Too much belly fat, even for people with a healthy BMI, raises heart risks

People with too much fat around their midsections and vital organs are at increased risk for heart disease, even if their body mass index falls within what is considered a healthy range, according to a new scientific report.

The statement from the American Heart Association, published Thursday in its journal Circulation, summarizes research on the ways in which belly fat and other measures of obesity affect heart health. Belly fat also is referred to as abdominal fat and visceral adipose tissue, or VAT.

“Studies that have examined the relationship between abdominal fat and cardiovascular outcomes confirm that visceral fat is a clear health hazard,” writing committee chair Dr. Tiffany Powell-Wiley said in a news release. Powell-Wiley is chief of the Social Determinants of Obesity and Cardiovascular Risk Laboratory at the National Heart, Lung, and Blood Institute in Bethesda, Maryland.

Whether a person has too much belly fat is typically determined using the ratio of waist circumference to height (taking body size into account) or waist-to-hip ratio. This measurement has been shown to predict cardiovascular death independent of BMI, a measure of obesity that is based on height and weight.

Experts recommend both abdominal measurement and BMI be considered during regular health care visits because even in healthy weight individuals, it could mean an increased heart disease risk. Abdominal obesity is also linked to fat accumulation around the liver. That often leads to non-alcoholic fatty liver disease, which adds to cardiovascular disease risk.

Worldwide, around 3 billion people are overweight or have obesity. The “obesity epidemic contributes significantly” to many chronic health conditions and cardiovascular disease cases around the world, Powell-Wiley said. Specifically, obesity is associated with a higher risk of coronary artery disease and death from cardiovascular disease. It contributes to high cholesterol, Type 2 diabetes, high blood pressure and sleep disorders.

Yet some people whose BMI classifies them as obese, but who have low levels of abdominal fat, are at lower risk for heart problems, the analysis showed.

Meeting federal guidelines for 150 minutes of physical activity per week may be sufficient to reduce abdominal fat, the analysis found, with no additional loss from longer activity times. Exercise alone or in combination with diet changes have been shown in some instances to reduce abdominal obesity even without weight loss.

Also, weight loss from lifestyle changes improves blood sugar, blood pressure, and triglyceride and cholesterol levels – a cluster of factors referred to as metabolic syndrome, according to the new statement. It also reduces inflammation, improves blood vessel function and helps non-alcoholic fatty liver disease.

In addition, intense weight loss may help curb atrial fibrillation, a quivering or irregular heartbeat, according to the report. Estimates suggest obesity may account for one-fifth of all cases.

The new scientific statement evaluated research on managing and treating obesity, particularly abdominal obesity. Experts concluded that reducing calories and aerobic exercise were the most beneficial.

Bariatric weight loss surgery has been shown to reduce the risk for coronary artery disease better than weight loss achieved without surgery. This may be due to the larger amount of weight loss achieved with surgery and the resultant changes in metabolism that are typical after bariatric surgery.

The statement also addresses what’s known as the “obesity paradox.” That is, even though overweight and obesity are strong risk factors for cardiovascular disease, in the short-term, they don’t always mean patients have worse survival outcomes. The analysis concludes this may be because people classified as overweight or obese are often screened earlier for cardiovascular disease than people with healthy weight, so they are diagnosed and treated earlier.

“The underlying mechanisms for the obesity paradox remain unclear,” Powell-Wiley said. “Despite the existence of the paradox for short-term cardiovascular disease outcomes, the data show that patients with overweight or obesity suffer from cardiovascular disease events at an earlier age, live with cardiovascular disease for more of their lives and have a shorter average lifespan than patients with normal weight.”

Article published courtesy of American Heart Association News

Close to half of U.S. population projected to have obesity by 2030

About half of the adult U.S. population will have obesity and about a quarter will have severe obesity by 2030, according to a new study led by Harvard T.H. Chan School of Public Health.

photo credit: Harvard T.H. Chan

The study also predicts that in 29 states, more than half of the population will have obesity, and all states will have a prevalence of obesity higher than 35%. The study’s researchers estimate that, currently, 40% of American adults have obesity and 18% have severe obesity.

The study was published in the December 19, 2019 issue of the New England Journal of Medicine.

The researchers said the predictions are troubling because the health and economic effects of obesity and severe obesity take a toll on several aspects of society. “Obesity, and especially severe obesity, are associated with increased rates of chronic disease and medical spending, and have negative consequences for life expectancy,” said Steven Gortmaker, professor of the practice of health sociology at Harvard Chan School and senior author of the study.

For the study, the researchers used self-reported body mass index (BMI) data from more than 6.2 million adults who participated in the Behavioral Risk Factor Surveillance System Survey (BRFSS) between 1993 and 2016. Body mass index (BMI) is calculated by dividing a person’s weight in kilograms by the square of their height in meters. Obesity is defined as a BMI of 30 or higher, and severe obesity is a BMI of 35 or higher.

Self-reported BMIs are frequently biased, so the researchers used novel statistical methods to correct for this bias.

The large amount of data collected in the BRFSS allowed the researchers to drill down for obesity rates for specific states, income levels, and subpopulations.

The results showed that by 2030, several states will have obesity prevalence close to 60%, while the lowest states will be approaching 40%. The researchers predicted that nationally, severe obesity will likely be the most common BMI category for women, non-Hispanic black adults, and those with annual incomes below $50,000 per year.

“The high projected prevalence of severe obesity among low-income adults has substantial implications for future Medicaid costs,” said lead author Zachary Ward, programmer/analyst at Harvard Chan School’s Center for Health Decision Science. “In addition, the effect of weight stigma could have far-reaching implications for socioeconomic disparities as severe obesity becomes the most common BMI category among low-income adults in nearly every state.”

Ward and his co-authors said that the study could help inform state policy makers. For example, previous research suggests that sugar-sweetened beverage taxes have been an effective and cost-effective intervention for curtailing the rise in obesity rates. “Prevention is going to be key to better managing this epidemic,” said Ward.

Study links irregular sleep patterns to metabolic disorders

A new study has found that not sticking to a regular bedtime and wakeup schedule, and getting different amounts of sleep each night, can put a person at higher risk for obesity, high cholesterol, hypertension, high blood sugar and other metabolic disorders. In fact, for every hour of variability in time to bed and time asleep, a person may have up to a 27% greater chance of experiencing a metabolic abnormality.

The results of the study, which was funded by the National Heart, Lung, and Blood Institute (NHLBI), part of the National Institutes of Health, appear today in the journal Diabetes Care(link is external).

“Many previous studies have shown the link between insufficient sleep and higher risk of obesity, diabetes, and other metabolic disorders,” said study author Tianyi Huang, Sc.D., epidemiologist of the Channing Division of Network Medicine at Brigham and Women’s Hospital, Boston. “But we didn’t know much about the impact of irregular sleep, high day-to-day variability in sleep duration and timing. Our research shows that, even after considering the amount of sleep a person gets and other lifestyle factors, every one-hour night-to-night difference in the time to bed or the duration of a night’s sleep multiplies the adverse metabolic effect.”

For the current study, researchers followed 2,003 men and women, ages 45 to 84, participating in the NHLBI-funded Multi-Ethnic Study of Atherosclerosis (MESA). The participants were studied for a median of six years to find out the associations between sleep regularity and metabolic abnormalities. To ensure objective measurement of sleep duration and quality, participants wore actigraph wrist watches to closely track sleep schedules for seven consecutive days. They also kept a sleep diary and responded to standard questionnaires about sleep habits and other lifestyle and health factors. Participants completed the actigraphy tracking between 2010 and 2013 and were followed until 2016 and 2017.

“Objective metrics and a big and diverse sample size are strengths of this study,” said Michael Twery, Ph.D., director of the NHLBI’s National Center on Sleep Disorders Research. “As is the study’s ability to look not only at current factors, but to conduct a prospective analysis that allowed us to assess whether patterns of irregular sleep could be linked to future metabolic abnormalities.”

The researchers’ hypothesis that there were, in fact, such associations, proved correct. Individuals with greater variations in their bedtimes and in the hours they slept had a higher prevalence of metabolic problems, and these associations persisted after adjusting for average sleep duration. This was also the case when they looked at the participants who developed metabolic disorders during the 6.3 years of follow up.

The prospective results showed that the variations in sleep duration and bedtimes preceded the development of metabolic dysfunction. According to the authors, this provides some evidence supporting a causal link between irregular sleep and metabolic dysfunction.

Participants whose sleep duration varied more than one hour were more likely to be African-Americans, work non-day shift schedules, smoke, and have shorter sleep duration. They also had higher depressive symptoms, total caloric intake, and index of sleep apnea.

Increasing sleep duration or bedtime variability was strongly associated with multiple metabolic and simultaneous problems such as lower HDL cholesterol and higher waist circumference, blood pressure, total triglycerides, and fasting glucose.

“Our results suggest that maintaining a regular sleep schedule has beneficial metabolic effects,” said study coauthor Susan Redline, M.D., senior physician in the Division of Sleep and Circadian Disorders at Brigham and Women’s Hospital. “This message may enrich current prevention strategies for metabolic disease that primarily focus on promoting sufficient sleep and other healthy lifestyles.” 

NIH study finds heavily processed foods cause overeating and weight gain

People eating ultra-processed foods ate more calories and gained more weight than when they ate a minimally processed diet, according to results from a National Institutes of Health study.

Researchers from the National Institutes of Health Kevin D. Hall, Ph.D., center, and Stephanie Chung, M.B.B.S., right, talk with a study participant at the NIH Clinical Center.Jennifer Rymaruk, NIDDK

The difference occurred even though meals provided to the volunteers in both the ultra-processed and minimally processed diets had the same number of calories and macronutrients. The results were published in Cell Metabolism(link is external).

This small-scale study of 20 adult volunteers, conducted by researchers at the NIH’s National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), is the first randomized controlled trial examining the effects of ultra-processed foods as defined by the NOVA classification system. This system considers foods “ultra-processed” if they have ingredients predominantly found in industrial food manufacturing, such as hydrogenated oils, high-fructose corn syrup, flavoring agents, and emulsifiers.

Previous observational studies looking at large groups of people had shown associations between diets high in processed foods and health problems. But, because none of the past studies randomly assigned people to eat specific foods and then measured the results, scientists could not say for sure whether the processed foods were a problem on their own, or whether people eating them had health problems for other reasons, such as a lack of access to fresh foods.

“Though we examined a small group, results from this tightly controlled experiment showed a clear and consistent difference between the two diets,” said Kevin D. Hall, Ph.D., an NIDDK senior investigator and the study’s lead author. “This is the first study to demonstrate causality — that ultra-processed foods cause people to eat too many calories and gain weight.”

For the study, researchers admitted 20 healthy adult volunteers, 10 male and 10 female, to the NIH Clinical Center for one continuous month and, in random order for two weeks on each diet, provided them with meals made up of ultra-processed foods or meals of minimally processed foods. For example, an ultra-processed breakfast might consist of a bagel with cream cheese and turkey bacon, while the unprocessed breakfast was oatmeal with bananas, walnuts, and skim milk.

The ultra-processed and unprocessed meals had the same amounts of calories, sugars, fiber, fat, and carbohydrates, and participants could eat as much or as little as they wanted.

Dietitians at the Clinical Center of the National Institutes of Health designed recipes to test the effects of ultra-processed and unprocessed diets on study participants.Jennifer Rymaruk, NIDDK

“We need to figure out what specific aspect of the ultra-processed foods affected people’s eating behavior and led them to gain weight,” Hall said. “The next step is to design similar studies with a reformulated ultra-processed diet to see if the changes can make the diet effect on calorie intake and body weight disappear.”

For example, slight differences in protein levels between the ultra-processed and unprocessed diets in this study could potentially explain as much as half the difference in calorie intake.

“Over time, extra calories add up, and that extra weight can lead to serious health conditions,” said NIDDK Director Griffin P. Rodgers, M.D. “Research like this is an important part of understanding the role of nutrition in health and may also help people identify foods that are both nutritious and accessible — helping people stay healthy for the long term.”

While the study reinforces the benefits of unprocessed foods, researchers note that ultra-processed foods can be difficult to restrict. “We have to be mindful that it takes more time and more money to prepare less-processed foods,” Hall said. “Just telling people to eat healthier may not be effective for some people without improved access to healthy foods.”

Too much dietary fat in the brain may impact mental health

A team of researchers from the University of Glasgow in the United Kingdom and the Gladstone Institutes, in San Francisco, CA, has recently studied how eating a diet high in saturated fats might make depression more likely, using mouse models to do so.

The investigators — led by Prof. George Baillie, from the University of Glasgow — note that this is a particularly important research topic, as obesity-related depression seems to happen via different mechanisms from depression in otherwise healthy individuals.

In its study paper, which appears in the journal Translational Psychiatry, the research team explains that many people with obesity and depression, who doctors treat with regular antidepressants, do not see any benefits from the treatment.

At the same time, people with obesity and depression also do not experience some of the side effects that people typically associate with those antidepressants, such as further weight gain.

“When compared with patients of normal body weight, overweight and obese patients showed a substantially slower response to antidepressant treatment, less improvement in neuroendocrinology and cognitive processing, and less antidepressant-induced weight gain,” the researchers write.

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Credit: MedicalNewsToday

Experts confirm breastfeeding protects against child obesity – New WHO studies

A new study from WHO/Europe shows that, despite efforts aimed at prevention, parts of the WHO European Region continue to struggle with comparably higher rates of childhood obesity, while a second study shows that babies who have never or only infrequently been breastfed have an increased risk of becoming obese as children.

Mother cuddling with her newborn baby in the living room. Photo credit: HuffPost UK

Progress on tackling the childhood obesity crisis has been slow and inconsistent throughout the Region, according to the 2 studies released at this year’s European Congress on Obesity in Glasgow, United Kingdom.

“The longer a child is breastfed, the greater their protection from obesity. This knowledge can strengthen our efforts in preventing obesity. Acting on childhood obesity – including severe obesity – can have major benefits, not only for child health and well-being, but also for national health care systems, so we must do all we can to promote and protect breastfeeding across the Region,” said Dr Bente Mikkelsen, Director of the Division of Noncommunicable Diseases and Promoting Health through the Life-course, WHO/Europe.

Consequences of severe obesity

Severe obesity in children is associated with immediate and long-term cardiovascular, metabolic and other negative health outcomes. When comparing overweight children to children with severe obesity, the latter have a much worse cardio-metabolic risk factor profile. According to the new WHO study, “Prevalence of severe obesity among primary school children in 21 European countries”, severe obesity affects almost 400 000 of the roughly 13.7 million children aged 6–9 years living in the 21 participating countries.

This study is the first that investigates the prevalence of severe obesity in school children. Severe obesity is a serious public health issue and the results of this study show that a large number of children in the European Region suffer from it. Given its impact on education, health, social care and the economy, the new report emphasizes that obesity needs to be addressed via a range of approaches, from prevention to early diagnosis and treatment.

Link between breastfeeding and obesity

The second study, “Association between characteristics at birth, breastfeeding and obesity, in 22 countries”, found that despite the consistent flow of research evidence showing the health benefits from breastfeeding, along with numerous policy initiatives aimed at promoting optimal breastfeeding practices, adoption of exclusive breastfeeding in the European Region remains below the global recommended level.

WHO recommends exclusive breastfeeding for the first 6 months of life. Thereafter, infants should be given nutritionally adequate complementary foods with continued breastfeeding up to 2 years of age or beyond.

This study showed that, in nearly all countries, more than 77% of children were breastfed; but there were a few exceptions – in Ireland 46% of children were never breastfed, in France 38% and in Malta 35%. Only 4 out of 12 countries had a prevalence of exclusive breastfeeding (for 6 months or more) of 25% or higher: Tajikistan (73%), Turkmenistan (57%), Kazakhstan (51%) and Georgia (35%).

According to the study, breastfeeding practices in the Region fall short of WHO recommendations for a number of reasons, including: inefficient policies to encourage breastfeeding, lack of preparation of health professionals to support breastfeeding, intensive marketing of breast milk substitutes, and problems in legislation on maternity protection.

“The promotion of breastfeeding presents a window of opportunity for obesity prevention policy to respond to the problem of childhood obesity in the European Region. Existing national policies to promote breastfeeding practices and how these policies are developed, can lead some countries to be more or less successful in combating obesity,” said Dr Joao Breda, Head of the WHO European Office for Prevention and Control of Noncommunicable Diseases, who also led the WHO Childhood Obesity Surveillance Initiative, known as COSI. Research from this initiative was used for both reports.

COSI was established more than 10 years ago to estimate prevalence and monitor changes in overweight and obesity in children aged 6–9 years. Since then, there have been 5 rounds of data collection in more than 40 countries and among more than half a million children.

To grow up healthy, children need to sit less and play more

Children under five must spend less time sitting watching screens, or restrained in prams and seats, get better quality sleep and have more time for active play if they are to grow up healthy, according to new guidelines issued by the World Health Organization (WHO).

“Achieving health for all means doing what is best for health right from the beginning of people’s lives,” says WHO Director-General Dr Tedros Adhanom Ghebreyesus. “Early childhood is a period of rapid development and a time when family lifestyle patterns can be adapted to boost health gains.”

The new guidelines on physical activity, sedentary behaviour and sleep for children under 5 years of age were developed by a WHO panel of experts. They assessed the effects on young children of inadequate sleep, and time spent sitting watching screens or restrained in chairs and prams. They also reviewed evidence around the benefits of increased activity levels.

Children playing at Boboh Beach in Sierra Leone. Photo credit: ABC

“Improving physical activity, reducing sedentary time and ensuring quality sleep in young children will improve their physical, mental health and wellbeing, and help prevent childhood obesity and associated diseases later in life,” says Dr Fiona Bull, programme manager for surveillance and population-based prevention of noncommunicable diseases, at WHO.

Failure to meet current physical activity recommendations is responsible for more than 5 million deaths globally each year across all age groups.  Currently, over 23% of adults and 80% of adolescents are not sufficiently physically active. If healthy physical activity, sedentary behaviour and sleep habits are established early in life, this helps shape habits through childhood, adolescence and into adulthood.

“What we really need to do is bring back play for children,” says Dr Juana Willumsen, WHO focal point for childhood obesity and physical activity. “This is about making the shift from sedentary time to playtime, while protecting sleep. “

The pattern of overall 24-hour activity is key: replacing prolonged restrained or sedentary screen time with more active play, while making sure young children get enough good-quality sleep. Quality sedentary time spent in interactive non-screen-based activities with a caregiver, such as reading, storytelling, singing and puzzles, is very important for child development.

The important interactions between physical activity, sedentary behaviour and adequate sleep time, and their impact on physical and mental health and wellbeing, were recognized by the Commission on Ending Childhood Obesity, which called for clear guidance on physical activity, sedentary behaviour and sleep in young children.

Applying the recommendations in these guidelines during the first five years of life will contribute to children’s motor and cognitive development and lifelong health