Bad break-ups may not trigger weight gain from emotional eating

October 17, 2019

Science Daily/Penn State

That pint of ice cream after a nasty breakup may not do as much damage as you think. Despite the emotional turmoil, people on average do not report gaining weight after a relationship dissolution, according to new research.

The study, which included researchers from Penn State, were investigating the German concept of "kummerspeck" -- excess weight gain due to emotional eating -- which literally translates to "grief bacon."

Marissa Harrison, associate professor of psychology at Penn State Harrisburg, said that while hoarding food after a breakup may have made sense for humans thousands of years ago, modern humans may have grown out of the habit.

"Food was much scarcer in the ancestral environment, so if your partner abandoned you, it could have made gathering food much harder," Harrison said. "It may have made sense if our ancestors hoarded food after a breakup. But our research showed that while it's possible people may drown their sorrows in ice cream for a day or two, modern humans do not tend to gain weight after a breakup."

According to the researchers, it has been well documented that people sometimes use food as a way to cope with negative feelings and that emotional eating can lead to unhealthy food choices. Because breakups can be stressful and emotional, it could potentially trigger emotional eating.

Additionally, ancient relationship dynamics may have made packing on the pounds after a breakup evolutionary advantageous.

"Modern women of course have jobs and access to resources now, but back then, it was likely that women were smaller and needed more protection and help with resources," Harrison said. "If their partner left or abandoned them, they would be in trouble. And the same could have gone for men. With food not as plentiful in the ancestral world, it may have made sense for people to gorge to pack on the pounds."

Harrison also noted that the existence of the word "kummerspeck" itself suggested that the phenomenon existed.

The researchers completed two studies to test the theory that people may be more likely to gain weight after a relationship breakup. In the first one, the researchers recruited 581 people to complete an online survey about whether they had recently gone through a breakup and whether they gained or lost weight within a year of that breakup.

Most of the participants -- 62.7 percent -- reported no weight change. According to Harrison, she and the other researchers were surprised by this result and decided to perform an additional study.

For the second study, the researchers recruited 261 new participants to take a different, more extensive survey than the one used in the first study. The new survey asked whether participants had ever experienced the dissolution of a long-term relationship, and whether they gained or lost weight as a result. The survey also asked about participants' attitudes toward their ex-partner, how committed the relationship was, who initiated the breakup, whether the participants tended to eat emotionally, and how much participants enjoy food in general.

While all participants reported experiencing a break up at some point in their lives, the majority of participants -- 65.13 percent -- reported no change in weight after relationship dissolution.

"We were surprised that in both studies, which included large community samples, we found no evidence of kummerspeck," Harrison said. "The only thing we found was in the second study, women who already had a proclivity for emotional eating did gain weight after a relationship breakup. But it wasn't common."

Harrison added that the results -- recently published in the Journal of the Evolutionary Studies Consortium -- may have clinical implications.

"It could be helpful information for clinicians or counselors with patients who tend to eat emotionally," Harrison said. "If your client is going through a breakup and already engages in emotional eating, this may be a time where they need some extra support."

https://www.sciencedaily.com/releases/2019/10/191017121930.htm

Overweight Danes are more likely to have overweight dogs

September 19, 2019

Science Daily/University of Copenhagen

A new study from the University of Copenhagen reports that the prevalence of overweight dogs is markedly larger among overweight owners than among normal weight owners. Part of the explanation lies in whether treats are used as training tools or "hygge-snacks." It is the first major study on canine obesity in Denmark.

There's a bit of truth to the saying "like owner, like dog." This has now been confirmed by researchers. For the first time in Denmark, researchers have systematically investigated the factors related to our four-legged friends being overweight or obese. One of the results demonstrates an unambiguous correlation between the weight status of a dog and its owner.

The study, conducted by researchers at the University of Copenhagen, shows that the prevalence of heavy or obese dogs is more than twice as large among overweight or obese owners than among owners who are slim or of a normal weight.

Part of the explanation rests upon how owners manage dog treats. The research results show a correlation between overweight dog owners and the use of dog treats as "hygge-candy" (cozy-candy).

"Whereas normal weight owners tend to use treats for training purposes, overweight owners prefer to provide treats for the sake of hygge. For example, when a person is relaxing on the couch and shares the last bites of a sandwich or a cookie with their dog," says Charlotte R. Bjørnvad of the University of Copenhagen's Department of Veterinary Clinical Sciences. Bjørnvad, a veterinarian and professor, is the main author of the research article, now published in the journal Preventive Veterinary Medicine.

The researchers studied 268 adult dogs recruited at animal clinics around Zealand and the Capital Region of Denmark. Of the pets recruited, 20% were either heavy or obese.

"Oftentimes, people don't consider their dog's weight status to be a problem. And this might contribute to a dog's being overweight. But being heavy or obese does have a great impact on dog health -- which on average results in a shortened lifespan," according to bioethics professor and article co-author, Peter Sandøe, of the University of Copenhagen's Department of Food and Resource Economics.

Previous studies have shown that on average, heavy dogs live 1.3 years less than dogs on restrictive diets and that part of the explanation may be an earlier development of osteoarthritis with the heavier weight.

Castration triples the risk of being heavy or obese

The researchers also looked into how castration and sterilization can be risk factors in relation to dog weight. The study shows that castrated male dogs have three times as high a risk of being heavy or obese compared to intact dogs. On the other hand, the study demonstrated that sterilization has no impact on weight in female dogs. Whether they are intact or not, female dogs, have an increased risk of being heavy compared with intact males.

"When males are castrated, they face just as high of a risk of becoming overweight as females. Castration seems to decrease the ability to regulate the appetite in male dogs and at the same time, it might also decrease the incentive to exercise which results in an increased risk of becoming overweight. Therefore, an owner should be careful about how they feed their dog after it has been castrated," says Bjørnvad.

Sandøe adds: "They might even want to consider not neutering. As long as there are no runaway females in the area, there are in most cases no reason to neuter."

The researchers hope that this new knowledge raises awareness about canine weight among veterinarians and dog owners, and that it contributes to better obesity prevention and treatment strategies by identifying focus areas for intervention.

https://www.sciencedaily.com/releases/2019/09/190919095230.htm

Deeper understanding of early life experiences can help combat chronic obesity and frequent bingeing

September 17, 2019

Science Daily/Elsevier

According to a new study in the journal Heliyon, published by Elsevier, dysfunctional eating patterns and habits in overweight and obese adults can be triggered by early life experiences that are deeply rooted within patients' personality features. As a result, weight loss interventions like surgery and cognitive-behavior therapy might not be sufficient to guarantee long-term success. Cognitive psychologists used the Schema Therapy (ST) model to gain a deeper understanding of the emotional and psychological functioning of these individuals with a view towards developing more effective treatment options.

"While the biological and environmental causes of obesity are well known, psychological determinants that might indicate chronic predispositions are less clear," explained lead investigator Barbara Basile, PhD, Association of Cognitive Psychology (APC), School of Cognitive Psychotherapy (SPC), Rome, Italy. "The results of our study suggest that dysfunctional eating patterns and habits associated with overweight and obesity are deeply rooted within patients' personality features and current interventions are not enough to guarantee a long-lasting effect."

The key concepts within the ST approach include Early Maladaptive Schemas, Schema Modes and dysfunctional Coping strategies. All of these develop across the life span and originated in early childhood and adolescence, where emotional core needs, such as love and nurturance, safety, acceptance, autonomy, limits setting, etc., might not have been adequately satisfied by caregivers and significant others.

Using an ST framework, investigators assessed early maladaptive schema and coping modes in 75 normal, overweight, and obese patients. Overweight and obese adults reported more maladaptive schemas and dysfunctional coping strategies when compared to normal-weight individuals. Moreover, investigators found that stressors trigger shifts from one coping mode to another, some predictive of frequent binge and bulimic behaviors.

Maladaptive schemas encapsulate dysfunctional thoughts and behaviors and map out patterns of perception, emotion, and physical sensation rooted in early life experiences that subsequently shape individuals' beliefs about themselves and the world. The dysfunctional schemas observed in obesity are linked to coping mechanisms resulting in self-defeating thoughts and emotion-avoidant food attitudes and behaviors.

"Our findings highlight the role of the Insufficient Self-Control schema among overweight and obese individuals, which manifests as difficulties in tolerating distress and restraining impulses. We also documented that overeating and bingeing behaviors serve as self-soothing strategies that help individuals to cut off their feelings and quiet their internalized 'Punitive Parent'," noted Professor Basile.

Among study participants, overeating and bingeing behaviors served as self-soothing strategies when they experienced feelings of abandonment (the belief others will be unavailable or unpredictable in their support or connection); dependence/incompetence (the belief that one has failed, or will fail in important life areas of achievement); and subjugation (the belief that one must surrender control to others), as well as to quiet internalized Punitive Parent voices (inner dialogue that is self-blaming, punishing, and abusive that causes one to detach emotionally and reject help). Frequent bingeing was associated with belief patterns of abandonment, enmeshment (being excessively emotionally involved and connected with others at the expense of full individuation or normal social development); and failure (the belief that one always fails in important life areas of achievement) schemas, as well as by those who react impulsively with anger and frustration (Impulsive/Undisciplined Child) and by those with a Punitive Parent inner dialogue.

Professor Basile and her co-investigators believe that this deeper understanding of the emotional and psychological functioning of obese patients, recognizing the impact of early life experiences, might help clinicians promote the long-term efficacy of psychological interventions in overeating related pathologies.

Identifying each patient's unique maladaptive schema and modes is the first step of ST intervention. To help the patient deal with their future needs and emotions in a healthier way, treatment might also include:

·      Addressing and satisfying the frustrated core emotional needs, embedded in the vulnerable child mode, in a safe therapeutic relationship.

·      De-potentiating the punitive parental mode and its destructive messages.

·      Reducing dysfunctional coping mechanisms, such as the detached protector self-soothing.

·      Expanding the healthy adult mode.

"Addressing actual schema modes and the connected early experiences within a caring and solid clinical setting, such as the one used within ST practice, might be of particular value for obese patients," concluded Professor Basile.

https://www.sciencedaily.com/releases/2019/09/190917133050.htm

Negative impacts of food insecurity on children's health

September 9, 2019

Science Daily/American University

Food insecurity -- uncertainty about or a lack of consistent access to food that meets the needs of household members -- is a persistent social problem in the United States that affected roughly 14.3 million households in 2018 and nearly 14% of households with children, according to the U.S. Department of Agriculture. A new paper by researchers at the Boston University School of Social Work (BUSSW) and American University's School of Public Affairs (AU SPA) confirms the negative impact of food insecurity on child health, suggesting the urgent need for policies to combat this problem.

"Previous studies have pointed to a negative impact of food insecurity on child health, but our paper uses rich, nationally representative data to rule out other explanations for this relationship," says study lead author Margaret M.C. Thomas, MSW, doctoral candidate at BUSSW. "By comparing the outcomes of children in food-secure homes to those in food-insecure homes who were alike with respect to a large number of other factors, we have been able to more definitively characterize the serious negative health impacts of food insecurity."

Published in the journal Pediatrics, the research by Thomas and colleagues Associate Professor Daniel P. Miller, PhD (Boston University), and Associate Professor Taryn W. Morrissey, PhD (American University), points to a unique and negative effect of household food insecurity on children's health that is not due to the composition of their homes, the safety of their neighborhoods, or their household's income or receipt of public assistance. Instead, it shows the pervasive negative impacts of household food insecurity on children's health. "Household food insecurity was related to significantly worse general health, some acute and chronic health problems, worse health care access, and heightened emergency department use for children," says Morrissey.

The team of researchers used propensity scoring (PS) methods to investigate the effects of food insecurity on children's health by leveraging the inclusion of a measure of household food insecurity in the nationally representative National Health Interview Survey (NHIS). The NHIS data also include a rich set of background information about families including demographic characteristics, economic information, public program participation, and adult physical and mental health outcomes.

Thomas and her colleagues believe that their analytic approach is an important improvement over previous studies that use traditional regression methods. Using PS methods allowed them to better assess the causal impact of food insecurity on key domains of child health and health care use.

"Propensity scoring, a quasi-experimental family of methods, seeks to mimic the context of an experimental design by comparing outcomes among children who differ with respect to the household's food insecurity but who are alike in all other observable ways," Thomas says. "Because of the highly detailed information in the NHIS data, we were able to create a sample that is balanced with respect to known predictors of food insecurity."

Data on the independent impact of food insecurity on child health helps guide efforts to prevent food insecurity and ameliorate its consequences. The researchers suggest immediate policy responses, such as an increase in federal SNAP (Supplemental Nutrition Assistance Program) benefits for families.

"There are clear and consistent harmful impacts of food insecurity on children's general health, chronic health, acute health, and access to health care," Thomas says. "Without intervention, household food insecurity will continue to detrimentally impact children's health."

https://www.sciencedaily.com/releases/2019/09/190909131110.htm

Sugar alters compounds that impact brain health in fruit flies

September 6, 2019

Science Daily/University of Michigan

When fruit flies are exposed to a high sugar diet, key metabolites associated with brain health become depleted, according to a University of Michigan study.

This finding could tell researchers why behaviors that change with the internal energy state, such as food intake, learning and memory, and sleep, change on high-nutrient diets.

When our bodies metabolize food, that food is broken down into metabolites -- small molecules that perform many functions in the body, including providing fuel to cells and activating or inhibiting enzyme production. The study, published in Nature Communications, examines how metabolites in the brains and bodies of fruit flies change as the flies transition between hunger and satiety.

Through the study, the researchers found that the flies' metabolic profiles change rapidly during the quick transition from hunger to satiety, with the flies' brains showing a larger change than their bodies. In particular, the high sugar diet lowered the levels the brain metabolites N-acetyl aspartate, or NAA, and kynurenine.

The alteration of metabolites could impact how quickly the fly senses satiety, causing it to eat more. In fact, U-M researchers previously found that an increase in a specific metabolite with a high sugar diet caused overeating and weight gain.

Although scientists aren't clear on the role of NAA in the brain, it appears to provide fuel for brain cells and balances osmolarity -- or regulates cell volume -- in the brain. Lower levels of another metabolite, kynurenine, which is produced in high levels during exercise, is associated with depression.

"What we found was a metabolic remodeling," said senior author Monica Dus, U-M assistant professor of molecular, cellular and developmental biology. "It wasn't just a gradual accumulation from an early to longer exposure, but by the seventh day on a high sugar diet, these fruit flies had a completely different metabolic profile."

Cancer cells also undergo this type of metabolic remodeling in order to fuel their growth, which is why diet may play a role in cancer treatment and a reason the Dus lab wanted to examine the shift of metabolites in the brain.

To examine how a high sugar diet affects the brains and bodies of fruit flies, the research team compared a group of fasting flies to a group of fed flies. In the fed flies, the researchers skipped giving them dinner, then fed them a breakfast of moderately sweet glucose jelly the next day.

The researchers mix the sugar jelly with blue or green dye, and after an hour, check the belly of the fly to make sure it's eaten. To make sure the animals have eaten their fill, the researchers put the flies on a lickometer covered with the glucose jelly. A lickometer is exactly what it sounds like: A meter that counts the number of times it has been licked.

Then, inside separate tubes, researchers freeze the sated flies as well as the group of fasting flies. This stops the metabolic process, so that researchers can look at what's going on in the flies' brains at the moment of satiety. The researchers shake the tubes, which shatters the fly. A sieve separates the fly's head, thorax, abdomen and legs. These parts were then sent to a company that uses mass spectrometry to measure the metabolites within the fly.

To help refine the list of metabolites in the flies, Alla Karnovsky, a research associate professor of computational medicine and bioinformatics at Michigan Medicine, created a tool called FlyScape. She based it on a previous tool she created for the analysis of human metabolomics data called MetScape. Like Metscape, Flyscape is open access: any researcher studying metabolites in fruit flies can use the software.

These tools help researchers look for patterns in metabolomics data. A researcher like Daniel Wilinski, a postdoctoral fellow in the Dus lab and first author of the manuscript, can input a list of metabolites found in her fruit fly subjects, as well as a list of genes from fruit flies, into Flyscape. The tool will produce visualizations of the metabolic networks of fruit flies.

"You can view the metabolites and genes that are changing between different conditions," Karnovsky said. "This helps us understand what biological processes are happening."

Co-author Peter Freddolino, assistant professor of biological chemistry and computational medicine and bioinformatics at Michigan Medicine, has worked with Dus on previous papers to study how a high sugar diet dulls the sense of taste in fruit flies.

"We examined what the changes in metabolites are that could be fundamentally perturbing the way that these cells were working," Freddolino said. "What this study tells us is what metabolomic pathways might be involved."

Ultimately, the study found that 20 metabolites, in addition to NAA and kynurenine, were impacted by sugar consumption. Next, says Dus, the research team plans to dial down into how changes in these metabolites impact the brain, altering food intake and affecting other conditions such as sleep, learning and memory.

https://www.sciencedaily.com/releases/2019/09/190906090559.htm

Poor diet can lead to blindness

September 3, 2019

Science Daily/University of Bristol

An extreme case of "fussy" or "picky" eating caused a young patient's blindness, according to a new case report published today in Annals of Internal Medicine.

The University of Bristol researchers who examined the case recommend clinicians consider nutritional optic neuropathy in any patients with unexplained vision symptoms and poor diet, regardless of BMI, to avoid permanent vision loss.

Nutritional optic neuropathy is a dysfunction of the optic nerve which is important for vision. The condition is reversible, if caught early. But, left untreated, it can lead to permanent structural damage to the optic nerve and blindness.

In developed countries like the UK, the most common causes of nutritional optic neuropathy are bowel problems or drugs that interfere with the absorption of various important nutrients from the stomach. Purely dietary causes are less common because food supply is good, but elsewhere in the world, poverty, war and drought are linked to malnutrition and higher rates of nutritional optic neuropathy.

Clinician scientists from Bristol Medical School and the Bristol Eye Hospital examined the case of a teenage patient who first visited his GP complaining of tiredness. The link between his nutritional status and vision was not picked up until much later, and by then, his visual impairment had become permanent.

Aside from being a "fussy eater," the patient had a normal BMI and height and no visible signs of malnutrition and took no medications. Initial tests showed macrocytic anemia and low vitamin B12 levels, which were treated with vitamin B12 injections and dietary advice. When the patient visited the GP a year later, hearing loss and vision symptoms had developed, but no cause was found. By age 17, the patient's vision had progressively worsened, to the point of blindness. Further investigation found the patient had vitamin B12 deficiency, low copper and selenium levels, a high zinc level, and markedly reduced vitamin D level and bone mineral density. Since starting secondary school, the patient had consumed a limited diet of chips, crisps, white bread, and some processed pork. By the time the patient's condition was diagnosed, the patient had permanently impaired vision.

The researchers concluded that the patient's 'junk food' diet and limited intake of nutritional vitamins and minerals resulted in the onset of nutritional optic neuropathy. They suggest the condition could become more prevalent in future, given the widespread consumption of 'junk food' at the expense of more nutritious options, and the rising popularity of veganism if the vegan diet is not supplemented appropriately to prevent vitamin B12 deficiency.

Dr Denize Atan, the study's lead author and Consultant Senior Lecturer in Ophthalmology at Bristol Medical School and Clinical Lead for Neuro-ophthalmology at Bristol Eye Hospital, said: "Our vision has such an impact on quality of life, education, employment, social interactions, and mental health. This case highlights the impact of diet on visual and physical health, and the fact that calorie intake and BMI are not reliable indicators of nutritional status."

The team recommends dietary history should be part of any routine clinical examination like asking about smoking and alcohol intake. This may avoid a diagnosis of nutritional optic neuropathy being missed or delayed as some associated visual loss can fully recover if the nutritional deficiencies are treated early enough.

https://www.sciencedaily.com/releases/2019/09/190903091437.htm

Suggested move to plant-based diets risks worsening brain health nutrient deficiency

Suggested move to plant-based diets risks worsening brain health nutrient deficiency

And UK failing to recommend or monitor dietary levels of choline, warns nutritionist

August 29, 2019

Science Daily/BMJ

The momentum behind a move to plant-based and vegan diets for the good of the planet is commendable, but risks worsening an already low intake of an essential nutrient involved in brain health, warns a nutritionist in the online journal BMJ Nutrition, Prevention & Health.

To make matters worse, the UK government has failed to recommend or monitor dietary levels of this nutrient -- choline -- found predominantly in animal foods, says Dr Emma Derbyshire, of Nutritional Insight, a consultancy specialising in nutrition and biomedical science.

Choline is an essential dietary nutrient, but the amount produced by the liver is not enough to meet the requirements of the human body.

Choline is critical to brain health, particularly during fetal development. It also influences liver function, with shortfalls linked to irregularities in blood fat metabolism as well as excess free radical cellular damage, writes Dr Derbyshire.

The primary sources of dietary choline are found in beef, eggs, dairy products, fish, and chicken, with much lower levels found in nuts, beans, and cruciferous vegetables, such as broccoli.

In 1998, recognising the importance of choline, the US Institute of Medicine recommended minimum daily intakes. These range from 425 mg/day for women to 550 mg/day for men, and 450 mg/day and 550 mg/day for pregnant and breastfeeding women, respectively, because of the critical role the nutrient has in fetal development.

In 2016, the European Food Safety Authority published similar daily requirements. Yet national dietary surveys in North America, Australia, and Europe show that habitual choline intake, on average, falls short of these recommendations.

"This is....concerning given that current trends appear to be towards meat reduction and plant-based diets," says Dr Derbyshire.

She commends the first report (EAT-Lancet) to compile a healthy food plan based on promoting environmental sustainability, but suggests that the restricted intakes of whole milk, eggs and animal protein it recommends could affect choline intake.

And she is at a loss to understand why choline does not feature in UK dietary guidance or national population monitoring data.

"Given the important physiological roles of choline and authorisation of certain health claims, it is questionable why choline has been overlooked for so long in the UK," she writes. "Choline is presently excluded from UK food composition databases, major dietary surveys, and dietary guidelines," she adds.

It may be time for the UK government's independent Scientific Advisory Committee on Nutrition to reverse this, she suggests, particularly given the mounting evidence on the importance of choline to human health and growing concerns about the sustainability of the planet's food production.

"More needs to be done to educate healthcare professionals and consumers about the importance of a choline-rich diet, and how to achieve this," she writes.

"If choline is not obtained in the levels needed from dietary sources per se then supplementation strategies will be required, especially in relation to key stages of the life cycle, such as pregnancy, when choline intakes are critical to infant development," she concludes.

https://www.sciencedaily.com/releases/2019/08/190829184143.htm

Excess body fat increases the risk of depression

August 27, 2019

Science Daily/Aarhus University

Carrying ten kilograms of excess body fat increases the risk of depression by seventeen per cent. The more fat, the greater the probability of developing depression. This is the main conclusion of a new study carried out by researchers from Aarhus University and Aarhus University Hospital, Denmark.

"Our study also indicated that the location of the fat on the body makes no difference to the risk of depression. This suggests that it is the psychological consequences of being overweight or obese which lead to the increased risk of depression, and not the direct biological effect of the fat. If the opposite was true we would have seen that fat located centrally on the body increased the risk the most, as it has the most damaging effect in biological terms," says the study's last author Dr. Søren Dinesen Østergaard.

He is professor at the Department of Clinical Medicine at Aarhus University and affiliated with the Department of Affective Disorders at Aarhus University Hospital.

Prior studies in the field have predominantly used Body Mass Index (BMI) to measure obesity. BMI is calculated solely on the basis of body weight and height and is therefore a fairly crude measure, that does not, for example, take build and muscle mass into account.

"BMI is an inaccurate way of measuring overweight and obesity. Many elite athletes with a large muscle mass and a low body fat mass will have a BMI above 25, which is classified as overweight according to the common definition. This obviously doesn't make much sense. Therefore, one of the strengths of our study is that we've been able to zoom in and look at the specific relationship between the amount of body fat and the risk of depression," explains Dr. Østergaard.

In the study, which has been published in the journal Translational Psychiatry, the researchers have analysed data from two large genetic data sets: the UK Biobank, which contains data on the correlation between genetic variants and physical measurements (including body fat mass distributed around parts of the body); and the Psychiatric Genomics Consortium, which contains information on the correlation between genetic variants and depression.

Dr. Østergaard also highlights his research group's choice of the 'Mendelian randomization' method as the main reason why the study was successful. He also emphasises that the findings are particularly significant in light of the fact that almost 40 per cent of the world's adult population is overweight.

"In addition to the known physical consequences of obesity such as diabetes and cardiovascular disease, there is also a significant and now well-documented psychological component, which needs to be dealt with as well. This is yet another argument for resolving the obesity epidemic," he says, before emphasising that it is important to have a balanced approach to the issue:

"As it appears to be the psychological consequences of obesity, such as a negative body image and low self-esteem that is the main driving force behind the increased risk of depression, society's efforts to combat obesity must not stigmatise, as this will probably increase the risk of depression even further. It is important to bear this in mind so we can avoid doing more harm than good in the effort to curb the obesity epidemic," says Dr. Østergaard.

FACTS ABOUT MENDELIAN RANDOMIZATION:

Mendelian randomization (named after the Austrian monk Gregor Mendel, who was the father of modern genetics) is a method which in recent years has helped researchers to overcome a major challenge associated with observational studies -- namely that of making causal inference. In observational studies researchers often find correlations between two conditions -- e.g. between obesity and depression -- where it is difficult, or rather impossible, to determine whether there is indeed a causal effect going from obesity to depression -- or vice versa. Mendelian randomization may solve this challenge.

Mendelian randomization can be described as nature's version of the randomised controlled trials that are carried out when testing whether a new drug has the desired (causal) effect in the treatment of a disease. In the clinical trials of drugs, lots are drawn to determine whether individual participants will receive the active drug or a placebo, without them knowing which treatment they have been assigned to. Instead, Mendelian randomization takes advantage of the fact that a completely natural randomization takes place during the formation of the sex cells (egg cells and sperm cells), which represent the origin of all human beings. When sex cells are formed, the parents' genetic variants -- including those that give rise to increased body fat- are randomly distributed. Therefore, some individuals will have received many of these variants and others less. In the study in question, the researchers have utilised this natural and random source of variation to determine whether people who have received many genetic variants for increased body fat have an increased risk of suffering depression.

THE RESEARCH RESULT -- MORE INFORMATION

Genetic epidemiological study utilising data from the UK Biobank (with information on the association between genetic variants and fat mass based on a study of 330,000 people) and the Psychiatric Genomics Consortium (with information on the association between genetic variants and depression based on a study of 135,000 people with depression and 345,000 control subjects).

https://www.sciencedaily.com/releases/2019/08/190827095100.htm

Junk food intake in children reduced by health education that addresses emotional issues

August 23, 2019

Science Daily/European Society of Cardiology

Teacher training followed by classroom education with information, activities, and emotional support improves lifestyles in teachers and students, according to research to be presented at ESC Congress 2019 together with the World Congress of Cardiology.(1) The study suggests that knowledge alone is insufficient to change behaviour.

"Numerous studies have addressed health issues in the school setting, but most have focused on physical activity and nutrition, with little attention to emotional issues such as self-esteem, depression and eating behaviours," said study author Dr Carolinne Santin Dal Ri, a paediatrician at the Institute of Cardiology of Rio Grande do Sul, Porto Alegre, Brazil.

The Happy Life, Healthy Heart programme randomly allocated ten public schools in the city of Frederico Westphalen, Brazil, to the intervention group (five schools) or control group (five schools). The study included 473 students aged 6 to 12 and 32 teachers. Baseline assessments included weight, height, physical activity, food intake, and health knowledge in children; and physical activity and food consumption in teachers. Measurements were repeated after the intervention was completed.

The intervention had two stages: teacher training followed by students in the classroom. Teachers attended four meetings over a four-month period, were given a booklet, and had access to video lessons. The material was in seven chapters:

1)    risk factors for cardiovascular diseases in childhood;

2)    choice of healthy foods;

3)    food labelling;

4)    sodium, sugars and fats;

5)    emotional health and quality of life;

6)    physical activity; and

7)    healthy practices and changes in habits.

Each section contained theory plus suggestions for classroom activities based on the theme, age of the children, and intended goals.

In the classroom, teachers covered one theme per week, including at least one activity.(2) Teachers were free to choose or amend the activities and could incorporate them into projects based on the school's syllabus. To encourage teacher participation, a group was created on a social network where they received messages and reminders from the researcher on the topic they were supposed to work on. Teachers also shared their own experiences. The researcher visited the intervention schools to stimulate teachers and offer guidance.

For the control group schools, teachers did not participate in the training course and students attended the school's usual classes about health and healthy eating based on the curriculum.

Both students and teachers benefitted from the intervention. The proportion of students following Brazilian Food Guide advice to avoid pizza/hamburgers and soft drinks increased significantly by 15% and 20%, respectively. In addition, there was a 28% increase in the number of teachers who were physically active.

Dr Santin Dal Ri said: "Children in both the intervention and control groups increased their level of health knowledge during the study. But only those in the intervention group changed their eating behaviours. This suggests that information on its own does not lead to lifestyle improvements. In our study, a programme that combined information with playful activities and emotional support was beneficial for children and teachers."

https://www.sciencedaily.com/releases/2019/08/190823080023.htm

How stress can curb the desire to eat in an animal model

August 16, 2019

Science Daily/University of Texas Health Science Center at Houston

Eating disorder researchers at The University of Texas Health Science Center at Houston (UTHealth) have discovered a neurocircuit in mice that, when activated, increased their stress levels while decreasing their desire to eat. Findings appear in Nature Communications.

The scientists believe their research could aid efforts to develop treatments for a serious eating disorder called anorexia nervosa, which has the highest mortality rate of any mental disorder, according to the National Institute of Mental Health. People with anorexia nervosa avoid food, severely restrict food, or eat very small quantities of only certain foods. Even when they are dangerously underweight, they may see themselves as overweight.

"We have identified a part of the brain in a mouse model that controls the impact of emotions on eating," said Qingchun Tong, PhD, the study's senior author and an associate professor in the Center for Metabolic and Degenerative Disease at McGovern Medical School at UTHealth.

Because mice and humans have similar nervous systems, Tong, the Cullen Chair in Molecular Medicine at UTHealth, believes their findings could shed light on the part of the human brain that regulates hunger.

The investigators believe they are among the first to demonstrate the role of this neurocircuit in the regulation of both stress and hunger.

While previous research has established that stress can both reduce and increase a person's desire to eat, the neural mechanisms that act on the regulation of eating by stress-related responses largely remain a mystery.

Tong's team focused on a neurocircuit connecting two parts of the mouse brain: the paraventricular hypothalamus, an eating-related zone in the brain, and the ventral lateral septum, an emotional zone in the brain. The neurocircuit acts as an on/off switch.

When researchers activated the neurocircuit, there was an increase in anxiety levels and a decrease in appetite. Conversely, when the investigators inhibited the neurocircuit, anxiety levels dropped and hunger increased.

The scientists used a research technique called optogenetics to turn the neurons in question on and off.

https://www.sciencedaily.com/releases/2019/08/190816191450.htm

Gut-brain connection helps explain how overeating leads to obesity

August 12, 2019

Science Daily/Baylor College of Medicine

A multi-institutional team reveals a previously unknown gut-brain connection that helps explain how those extra servings lead to weight gain.

Eating extra servings typically shows up on the scale later, but how this happens has not been clear. A new study published today in the Journal of Clinical Investigation by a multi-institutional team led by researchers at Baylor College of Medicine reveals a previously unknown gut-brain connection that helps explain how those extra servings lead to weight gain.

Mice consuming a high-fat diet show increased levels of gastric inhibitory polypeptide (GIP), a hormone produced in the gut that is involved in managing the body's energy balance. The study reports that the excess GIP travels through the blood to the brain where it inhibits the action of leptin, the satiety hormone; consequently, the animals continue eating and gain weight. Blocking the interaction of GIP with the brain restores leptin's ability to inhibit appetite and results in weight loss in mice.

"We have uncovered a new piece of the complex puzzle of how the body manages energy balance and affects weight," said corresponding author Dr. Makoto Fukuda, assistant professor of pediatrics at Baylor and the USDA/ARS Children's Nutrition Research Center at Baylor and Texas Children's Hospital.

Researchers know that leptin, a hormone produced by fat cells, is important in the control of body weight both in humans and mice. Leptin works by triggering in the brain the sensation of feeling full when we have eaten enough, and we stop eating. However, in obesity resulting from consuming a high-fat diet or overeating, the body stops responding to leptin signals -- it does not feel full, and eating continues, leading to weight gain.

"We didn't know how a high-fat diet or overeating leads to leptin resistance," Fukuda said. "My colleagues and I started looking for what causes leptin resistance in the brain when we eat fatty foods. Using cultured brain slices in petri dishes we screened blood circulating factors for their ability to stop leptin actions. After several years of efforts, we discovered a connection between the gut hormone GIP and leptin."

GIP is one of the incretin hormones produced in the gut in response to eating and known for their ability to influence the body's energy management. To determine whether GIP was involved in leptin resistance, Fukuda and his colleagues first confirmed that the GIP receptor, the molecule on cells that binds to GIP and mediates its effects, is expressed in the brain.

Then the researchers evaluated the effect blocking the GIP receptor would have on obesity by infusing directly into the brain a monoclonal antibody developed by Dr. Peter Ravn at AstraZeneca that effectively prevents the GIP-GIP receptor interaction. This significantly reduced the body weight of high-fat-diet-fed obese mice.

"The animals ate less and also reduced their fat mass and blood glucose levels," Fukuda said. "In contrast, normal chow-fed lean mice treated with the monoclonal antibody that blocks GIP-GIP receptor interaction neither reduced their food intake nor lost body weight or fat mass, indicating that the effects are specific to diet-induced obesity."

Further experiments showed that if the animals were genetically engineered to be leptin deficient, then the treatment with the specific monoclonal antibody did not reduce appetite and weight in obese mice, indicating that GIP in the brain acts through leptin signaling. In addition, the researchers identified intracellular mechanisms involved in GIP-mediated modulation of leptin activity.

"In summary, when eating a balanced diet, GIP levels do not increase and leptin works as expected, triggering in the brain the feeling of being full when the animal has eaten enough and the mice stop eating," Fukuda said. "But, when the animals eat a high-fat diet and become obese, the levels of blood GIP increase. GIP flows into the hypothalamus where it inhibits leptin's action. Consequently, the animals do not feel full, overeat and gain weight. Blocking the interaction of GIP with the hypothalamus of obese mice restores leptin's ability to inhibit appetite and reduces body weight."

These data indicate that GIP and its receptor in the hypothalamus, a brain area that regulates appetite, are necessary and sufficient to elicit leptin resistance. This is a previously unrecognized role of GIP on obesity that plays directly into the brain.

Although more research is needed, the researchers speculate that these findings might one day be translated into weight loss strategies that restore the brain's ability to respond to leptin by inhibiting the anti-leptin effect of GIP.

https://www.sciencedaily.com/releases/2019/08/190812160533.htm

High-fat diets affect your brain, not just your physical appearance

September 9, 2019

Science Daily/Yale University

Much research has pointed to how an unhealthy diet correlates to obesity, but has not explored how diet can bring about neurological changes in the brain. A recent Yale study has discovered that high-fat diets contribute to irregularities in the hypothalamus region of the brain, which regulates body weight homeostasis and metabolism.

Led by Sabrina Diano, the Richard Sackler Family Professor of Cellular & Molecular Physiology and professor of neuroscience and comparative medicine, the study evaluated how the consumption of a high-fat diet -- specifically diets that include high amounts of fats and carbohydrates -- stimulates hypothalamic inflammation, a physiological response to obesity and malnutrition.

The researchers reaffirmed that inflammation occurs in the hypothalamus as early as three days after consumption of a high-fat diet, even before the body begins to display signs of obesity. "We were intrigued by the fact that these are very fast changes that occur even before the body weight changes, and we wanted to understand the underlying cellular mechanism," said Diano who is also a member of the Yale Program in Integrative Cell Signaling and Neurobiology of Metabolism.

The researchers observed hypothalamic inflammation in animals on a high fat diet and discovered that changes in physical structure were occurring among the microglial cells of animals. These cells act as the first line of defense in the central nervous system that regulate inflammation. Diano's lab found that the activation of the microglia was due to changes in their mitochondria, organelles that help our bodies derive energy from the food we consume. The mitochondria were substantially smaller in the animals on a high-fat diet. The mitochondria's change in size was due to a protein, Uncoupling Protein 2 (UCP2), which regulates the mitochondria's energy utilization, affecting the hypothalamus' control of energy and glucose homeostasis.

The UCP2-mediated activation of microglia affected neurons in the brain that, when receiving an inflammatory signal due to the high fat diet, stimulated the animals in the high-fat diet group to eat more and become obese. However, when this mechanism was blocked by removing the UCP2 protein from microglia, animals exposed to a high fat diet ate less and were resistant to gain weight.

The study not only illustrates how high-fat diets affect us physically, but conveys how an unhealthy diet can alter our food intake neurologically. "There are specific brain mechanisms that get activated when we expose ourselves to specific type of foods. This is a mechanism that may be important from an evolutionary point of view. However, when food rich in fat and carbs is constantly available it is detrimental."

Diano's long-standing goal is to understand the physiological mechanisms that regulate how much food we consume, and she continues to perform research on how activated microglia can affect various diseases in the brain, including Alzheimer's disease, a neurological disorder that is associated with changes in the brain's microglial cells and has been shown to have higher incidence among obese individuals.

https://www.sciencedaily.com/releases/2019/09/190909121234.htm

Curbing your enthusiasm for overeating

Mouse study focuses on cannabis-like molecules that augment feeding behavior

June 11, 2019

Science Daily/University of California - Riverside

Signals between our gut and brain control how and when we eat food. But how the molecular mechanisms involved in this signaling are affected when we eat a high-energy diet and how they contribute to obesity are not well understood.

Using a mouse model, a research team led by a biomedical scientist at the University of California, Riverside, has found that overactive endocannabinoid signaling in the gut drives overeating in diet-induced obesity by blocking gut-brain satiation signaling.

Endocannabinoids are cannabis-like molecules made naturally by the body to regulate several processes: immune, behavioral, and neuronal. As with cannabis, endocannabinoids can enhance feeding behavior.

The researchers detected high activity of endocannabinoids at cannabinoid CB1 receptors in the gut of mice that were fed a high-fat and sugar -- or Western -- diet for 60 days. This overactivity, they found, prevented the food-induced secretion of the satiation peptide cholecystokinin, a short chain of amino acids whose function is to inhibit eating. This resulted in the mice overeating. Cannabinoid CB1 receptors and cholecystokinin are present in all mammals, including humans.

Study results appear in the journal Frontiers in Physiology, an open-access journal.

"If drugs could be developed to target these cannabinoid receptors so that the release of satiation peptides is not inhibited during excessive eating, we would be a step closer to addressing the prevalence of obesity that affects millions of people in the country and around the world," said Nicholas V. DiPatrizio, an assistant professor of biomedical sciences in the UCR School of Medicine who led the research team.

DiPatrizio explained that previous research by his group on a rat model showed that oral exposure to dietary fats stimulates production of the body's endocannabinoids in the gut, which is critical for the further intake of high-fat foods. Other researchers, he said, have found that levels of endocannabinoids in humans increased in blood just prior to and after eating a palatable high-energy food, and are elevated in obese humans.

"Research in humans has shown that eating associated with a palatable diet led to an increase in endocannabinoids -- but whether or not endocannabinoids control the release of satiation peptides is yet to be determined," said Donovan A. Argueta, a doctoral student in DiPatrizio's lab and the first author of the research paper.

Previous attempts at targeting the cannabinoid CB1 receptors with drugs such as Rimonabant -- a CB1 receptor blocker -- failed due to psychiatric side effects. However, the DiPatrizio lab's current study suggests it is possible to target only the cannabinoid receptors in the gut for therapeutic benefits in obesity, greatly reducing the negative side effects.

The research team plans to work on getting a deeper understanding of how CB1 receptor activity is linked to cholecystokinin.

"We would also like to get a better understanding of how specific components of the Western diet -- fat and sucrose -- lead to the dysregulation of the endocannabinoid system and gut-brain signaling," DiPatrizio said. "We also plan to study how endocannabinoids control the release of other molecules in the intestine that influence metabolism."

https://www.sciencedaily.com/releases/2019/06/190611081915.htm

Offering children a variety of vegetables increases acceptance

September 9, 2019

Science Daily/Elsevier

Although food preferences are largely learned, dislike is the main reason parents stop offering or serving their children foods like vegetables. A new study in the Journal of Nutrition Education and Behavior, published by Elsevier, demonstrated that repeatedly offering a variety of vegetables increased acceptance and consumption by children.

"In Australia, dietary guidelines for vegetable consumption by young children have increased although actual consumption is low," said lead author Astrid A.M. Poelman, PhD, CSIRO Agriculture & Food, Sensory, Flavour and Consumer Science, North Ryde, Australia. "This study introduces an effective strategy for parents wanting to address this deficiency."

This study recruited 32 families with children between the ages of four and six where low consumption of vegetables was reported. Parents completed an online survey and attended an information meeting prior to participating. Three groups were created: children introduced to a single vegetable; children to receive multiple vegetables; and a group where eating habits were not changed.

Study data were collected in several ways: two dinner meals served at the research facility during which children could eat as much of the broccoli, cauliflower and green beans as they wished; changes to actual vegetables consumed at home, childcare or school recorded through food diaries; and parents reporting on usual vegetable consumption.

Strategies of offering vegetables were parent led and home based. Families introducing one vegetable served broccoli and families trying multiple vegetables served broccoli, zucchini and peas. Parents were provided with a voucher to purchase the vegetables and given instructions on portion size and cooking instructions along with tips on how to offer the vegetables. Children were served a small piece of vegetable three times a week for five weeks. A sticker was given as a reward to children trying a vegetable.

There was no difference between groups at the start of the study for any of the methods measured. The dinner meal, during which the children ate without parents present, did not increase consumption perhaps due to an unfamiliar setting. Vegetable acceptance increased for both the single and multiple vegetable groups during the intervention. Families that offered multiple vegetables recorded an increase in consumption from .6 to 1.2 servings, while no change in consumption was observed in families serving a single vegetable or families that did not change their eating habits. Increased acceptance for multiple vegetables was noted during the five weeks of the study and sustained at three-month followup. Following the study parents reported that offering the vegetables was "very easy" or "quite easy" with the majority following the instructions provided by the study.

Dr. Poelman recommended, "While the amount of vegetables eaten increased during the study, the amount did not meet dietary guidelines. Nonetheless, the study showed the strategy of offering a variety of vegetables was more successful in increasing consumption than offering a single vegetable."

https://www.sciencedaily.com/releases/2019/09/190909123713.htm

Overweight kids actually eat less right after stressful events

September 3, 2019

Science Daily/University of Michigan

A new study recently found that overweight adolescents -- considered particularly susceptible to stress eating -- actually ate less when exposed to a lab stressor.

People often react to stress by binging on sweets or fattening comfort foods, cravings fueled by the appetite-stimulating stress hormone cortisol.

But overweight adolescents -- considered particularly susceptible to stress eating -- actually ate less when exposed to a lab stressor, and the foods they eschewed were the high fat and sugar options, according to a University of Michigan study.

Even more surprising, kids who produced the most cortisol after the stressor saw the biggest appetite reduction, eating about 35% fewer calories in the two hours after the stressor, said principal investigator Rebecca Hasson, associate professor of movement science at the U-M School of Kinesiology.

Results were similar whether adolescents in the study were monitoring their food intake or not. This matters because people who restrict calories are more likely to stress eat.

That didn't happen among these dieters, and the results suggest that a biological response -- such as the flood of cortisol or the satiety hormone leptin -- drove the adolescents' reduced appetite.

Hasson and colleague Matthew Nagy, the study's first author and an alumnus of the U-M School of Public Health, wanted to understand how biology and behavior impacted the eating patterns of overweight kids.

"These are really exciting findings because they give us a chance to observe eating patterns when adults are exposed to stress, which is a very important factor in childhood obesity, long-term cardiovascular risk and type 2 diabetes risk," said Hasson, who also leads the U-M Childhood Disparities Research Lab and is an associate professor of nutritional sciences in the School of Public Health.

"This doesn't mean stress kids out and they'll lose weight. This is in the short term only. They may eat more calories later. Typically, many kids did say they turned to food when stressed, so maybe this was a time effect."

Also, even if the cortisol spike didn't cause overeating, it's still metabolically unhealthy, she said.

The study, which appears in Psychosomatic Medicine, involved about 60 kids.

Hasson said much work remains to see who's susceptible to big cortisol spikes and the long-term effects of stress. Previous studies have found that overweight adults with high cortisol responses after stress also experience short-term calorie reduction.

https://www.sciencedaily.com/releases/2019/09/190903084044.htm

Extra weight in 60s may be linked to brain thinning years later

July 24, 2019

Science Daily/University of Miami Miller School of Medicine

Having a bigger waistline and a high body mass index (BMI) in your 60s may be linked with greater signs of brain aging years later, according to a study published by a leading University of Miami neurologist researcher in the July 24, 2019, online issue of Neurology®, the medical journal of the American Academy of Neurology. The study suggests that these factors may accelerate brain aging by at least a decade.

"People with bigger waists and higher BMI were more likely to have thinning in the cortex area of the brain, which implies that obesity is associated with reduced gray matter of the brain," said study author Tatjana Rundek, M.D., Ph.D., a UHealth neurologist, professor of neurology, epidemiology, and public health and scientific director of the Evelyn F. McKnight Brain Research Institute.

"These associations were especially strong in those who were younger than 65, which adds weight to the theory that having poor health indicators in mid-life may increase the risk for brain aging and problems with memory and thinking skills in later life," said Dr. Rundek,

The study involved 1,289 people with an average age of 64. Two-thirds of the participants were Latino. Participants' BMI and waist circumference were measured at the beginning of the study. An average of six years later, participants had MRI brain scans to measure the thickness of the cortex area of the brain, overall brain volume and other factors.

A total of 346 of the participants had a BMI of less than 25, which is considered normal weight; 571 people had a BMI of 25 to 30, which is considered overweight; and 372 people had a BMI of 30 or higher, which is considered obese.

For waist circumference, which can be different for men and women, the normal weight group, which was 54 percent women, had an average of 33 inches, the overweight group, which was 56 percent women, had an average of 36 inches, and the obese group, which was 73 percent women, had an average of 41 inches.

Having a higher BMI was associated with having a thinner cortex, even after researchers adjusted for other factors that could affect the cortex, such as high blood pressure, alcohol use and smoking. In overweight people, every unit increase in BMI was associated with a 0.098 millimeter (mm) thinner cortex and in obese people with a 0.207 mm thinner cortex. Having a thinner cortex has been tied to an increased risk of Alzheimer's disease.

Having a bigger waist was also associated with a thinner cortex after adjusting for other factors.

Rundek said, "In normal aging adults, the overall thinning rate of the cortical mantle is between 0.01 and 0.10 mm per decade, and our results would indicate that being overweight or obese may accelerate aging in the brain by at least a decade."

"These results are exciting because they raise the possibility that by losing weight, people may be able to stave off aging of their brains and potentially the memory and thinking problems that can come along with brain aging," Rundek said. "However, with the rising number of people globally who are overweight or obese and the difficulty many experience with losing weight, obviously this is a concern for public health in the future as these people age."

Rundek noted that the study does not prove that extra weight causes the cortex to get thinner; it only shows an association.

A limitation of the study was that, like many studies of older people, it is possible that the healthiest people are more likely to live longer and take part in studies, so that may affect the results. 

https://www.sciencedaily.com/releases/2019/07/190724161155.htm

Warning to those wanting to spice up their lives

July 22, 2019

Science Daily/University of South Australia

Think twice before adding that extra kick of chili sauce or chopped jalapeno to your meal. New research involving the University of South Australia shows a spicy diet could be linked to dementia.

A 15-year study of 4582 Chinese adults aged over 55 found evidence of faster cognitive decline in those who consistently ate more than 50 grams of chili a day. Memory decline was even more significant if the chili lovers were slim.

The study, led by Dr Zumin Shi from Qatar University, showed that those who consumed in excess of 50 grams of chili a day had almost double the risk of memory decline and poor cognition.

"Chili consumption was found to be beneficial for body weight and blood pressure in our previous studies. However, in this study, we found adverse effects on cognition among older adults," Dr Zumin says.

UniSA epidemiologist Dr Ming Li, one of five researchers involved in the study, says chili intake included both fresh and dried chili peppers but not sweet capsicum or black pepper.

"Chili is one of the most commonly used spices in the world and particularly popular in Asia compared to European countries," Dr Li says. "In certain regions of China, such as Sichuan and Hunan, almost one in three adults consume spicy food every day."

Capsaicin is the active component in chili which reportedly speeds up metabolism, fat loss and inhibits vascular disorders but this is the first longitudinal study to investigate the association between chili intake and cognitive function.

Those who ate a lot of chili had a lower income and body mass index (BMI) and were more physically active compared to non-consumers. Researchers say people of normal body weight may be more sensitive to chili intake than overweight people, hence the impact on memory and weight. Education levels may also play a role in cognitive decline and this link requires further research.

https://www.sciencedaily.com/releases/2019/07/190722105939.htm

Jogging and five other exercises ward off weight gain despite 'obesity genes'

August 1, 2019

Science Daily/PLOS

For people who inherited genes that increase their chance of becoming obese, there is hope for keeping the weight off. A study by Wan-Yu Lin of National Taiwan University and colleagues, published 1st August in PLOS Genetics, identified the types of exercise that are especially effective at combating genetic effects that contribute to obesity.

Worldwide, obesity is a challenging condition to control because it results from interactions between a person's genetics and lifestyle. Doctors often recommend exercise, but it is not clear which kinds are best for curbing weight gain in individuals whose genetics make them more likely to become obese. A new study of 18,424 Han Chinese adults, aged 30 to 70 years, examined the interactions between the individuals' genetics and their self-reported exercise routines. The researchers looked specifically at five measures of obesity, such as body mass index (BMI), body fat percentage and waist-to-hip ratio. They found that regular jogging was the best type of exercise for managing obesity, according to the five measures. Moreover, mountain climbing, walking, power walking, certain types of dancing, and long yoga practices also reduce BMI in individuals predisposed to obesity. Surprisingly, cycling, stretching exercises, swimming and Dance Dance Revolution did not counteract the genetic effects on obesity.

Overall, the study suggests that when it comes to obesity, genetics are not destiny, and the effects can be lessened by several kinds of regular exercise. Previous research has shown that frequent physical activity blunts the genetic effects on obesity, but these studies focused only on BMI. The new study also considers four other measures of obesity that are more closely linked to metabolic problems. As obesity continues to be a serious public health challenge, the benefits of exercise cannot be overstated.

https://www.sciencedaily.com/releases/2019/08/190801142527.htm

Weight stigma in men associated with harmful health consequences

July 30, 2019

Science Daily/UConn Rudd Center for Food Policy and Obesity

As many as 40% of men report experiencing weight stigma, but little is known about how this stigma affects their health. This study found that men experiencing weight stigma have more depressive symptoms, are more likely to binge eat, and have lower self-rated health.

Men's health may be compromised by weight stigma, finds the latest research from the Rudd Center for Food Policy and Obesity at the University of Connecticut.

Weight stigma is pervasive against people with obesity, and can contribute to both physical and emotional health problems for those targeted. As many as 40% of men report experiencing weight stigma, but when it comes to how this stigma affects their health, men have received less attention in research compared to women.

"It's often assumed that conversations about weight loss, poor body image, and dieting are more salient for women. Men are frequently overlooked, but that does not necessarily mean that men are less affected by weight stigma or less likely to internalize negative biases," says Mary Himmelstein, lead author of the study.

The research, published in the journal Obesity, involved two groups of men: 1,249 men from a diverse national survey panel, and 504 men from an online data collection service. Both groups of men completed identical surveys about their experiences of weight-based stigma, how much they internalized these experiences (e.g., blamed themselves), as well as their psychological wellbeing and health behaviors.

Key findings include:

 ·     Both experienced and internalized weight stigma were associated with more depressive symptoms and more dieting behaviors.

·     Men who experienced weight stigma had increased odds of engaging in binge eating.

·     Men who internalized weight stigma had lower self-rated health.

These findings suggest the need for increased attention to men not only in research on links between weight stigma and health, but also among health professionals treating men for various health conditions, in which weight stigma may play a contributing role. In particular, it may be useful for health care providers to ask men about weight stigma to help identify those who may be vulnerable to depression or disordered eating behaviors, which are underdiagnosed in men.

"Our study shows that weight stigma is not a gendered issue. It can affect men's health in the same damaging ways in which we already know that it harms women's health, and neglecting these issues in men, either in research or clinical practice, may put them at a serious disadvantage in treatment," says Himmelstein. "Opportunities for supportive interventions should be available for men, women, and non-binary individuals alike to help them cope with weight stigma in less harmful ways."

https://www.sciencedaily.com/releases/2019/07/190730083717.htm

Individuals with obesity get more satisfaction from their food

July 30, 2019

Science Daily/Elsevier

A new study found no significant difference in taste perceptions between participants of normal weight and those who were overweight. However, participants with obesity had initial taste perceptions that were greater than participants who were not obese, which declined at a more gradual rate than participants who were not obese. This quantification of satisfaction from food may help explain why some people eat more than others.

The propensity to overeat may, in part, be a function of the satisfaction derived from eating. A new study in the Journal of the Academy of Nutrition and Dietetics, published by Elsevier, found no significant difference in taste perceptions between participants of normal weight and those who were overweight. However, participants with obesity had initial taste perceptions that were greater than participants who were not obese, which declined at a more gradual rate than participants who were not obese. This quantification of satisfaction from food may help explain why some people eat more than others.

"Obesity is a major public-health problem. Thirty percent of the US population is obese, and obesity-related health problems (diabetes, hypertension, etc.) are increasing. Causes of obesity are varied, but food consumption decisions play an important role, especially decisions about what foods to eat and how much to consume. Taste perceptions may lead to overeating. If people with obesity have different taste perceptions than nonobese people, it could lead to better understanding of obesity and possibly designing new approaches to prevent obesity," explained lead investigator Linnea A. Polgreen, PhD, Department of Pharmacy Practice and Science, University of Iowa, Iowa City, IA, USA.

As individuals consume more of a food item, they experience diminishing marginal taste perception, which means their level of perceived taste from additional consumption may tend to decline (ie, additional consumption may become less pleasurable). The relationship between perceived taste and quantity consumed has traditionally been referred to as sensory-specific satiety.

In order to determine if marginal taste perceptions differ among participants of normal-weight, those who are overweight and those with obesity, and whether knowledge of nutritional information affects marginal taste perception, researchers at the University of Iowa conducted a non-clinical, randomized controlled trial of 290 adults (161 with normal BMI, 78 considered overweight, and 51 considered obese) to measure instantaneous taste perceptions. Eighty percent of the participants were female, and ages ranged from 18 to 75 years. Participants were offered and rated one piece of chocolate at a time in a controlled environment and could eat as much as they wanted without feeling uncomfortable. They consumed between two and 51 pieces. Half of the study participants received nutritional information about the chocolate before the chocolate tasting began.

The study identified a consistent association between taste from food, specifically chocolate, and BMI by directly observing instantaneous taste changes over a period of time, rather than just at the beginning and end of a period of consumption, as in prior studies.

Typically, the appeal of a specific food may decline as more of that food is eaten: the first bite of chocolate is better than the 10th, a phenomenon consistent with the concept of sensory-specific satiety. As anticipated, researchers found that ratings generally went down after each piece of chocolate consumed with no significant difference in taste perceptions between normal and overweight participants reported. However, participants with obesity had higher levels of initial taste perception, rated subsequent pieces higher than their counterparts without obesity, and their ratings declined at a more gradual rate compared to participants with normal weight and those with obesity. People hungrier prior to the study had greater taste perception; women's taste perceptions declined faster than men's; and providing nutritional information prior to chocolate consumption did not affect taste perception.

"In our study population, people with obesity reported a higher level of satisfaction for each additional piece of chocolate compared to nonobese people. Thus, their taste preferences appear markedly different," noted co-investigator Aaron C. Miller, PhD, Department of Epidemiology, University of Iowa, Iowa City, IA, USA. "Our findings further indicate that obese participants needed to consume a greater quantity of chocolate than nonobese participants to experience a similar decline in taste perceptions. Specifically, obese women needed to eat 12.5 pieces of chocolate to fall to the same level of taste perception as nonobese women who ate only 10 pieces, which corresponds to a difference of 67.5 calories. This may, in part, explain why obese people consume more than nonobese people."

These findings suggest that understanding and manipulating taste perceptions, in addition to targeting nutritional awareness, may be crucial to understanding and preventing obesity. Strategies that work for individuals of normal-weight or those who are overweight may not work as effectively for individuals with obesity if they derive more satisfaction from eating additional amounts of food. If these findings are generalizable to other foods, they may help inform future interventions.

https://www.sciencedaily.com/releases/2019/07/190730083710.htm