Tag Archives: #weightloss

Caloric Restriction Alters Microbiome, Enhancing Weight Loss (Medicine)

Researchers at UCSF have found that extreme caloric restriction diets alter the microbiome in ways that could help with weight loss but might also result in an increased population of Clostridiodes difficile, a pathogenic bacterium that can lead to severe diarrhea and colitis.

Such diets, which allow people only 800 calories per day in liquid form, are an effective approach to weight loss in people with obesity. The unexpected results of this study raise the question of how much the microbiome influences weight loss and which bacteria are significant in that process. The study appears in the June 23, 2021, issue of Nature.

“Our results underscore that the role of calories in weight management is much more complex than simply how much energy a person is taking in,” said Peter Turnbaugh, PhD, an associate professor of microbiology and immunology and a senior author on the study. “We found that this very-low-calorie diet profoundly altered the gut microbiome, including an overall decrease in gut bacteria.”

Turnbaugh and his research team leveraged a clinical trial looking at a very-low-calorie liquid diet. That trial, which resulted in successful weight loss for many of the participants, was led by Joachim Spranger, MD, a professor of endocrinology and metabolic diseases at Charité Universitätsmedizin in Berlin, and co-senior author on the Nature study.

To investigate the microbial connection between this very-low-calorie diet and shedding pounds, Spranger’s team collected and sequenced fecal samples from 80 participants – all of whom were post-menopausal women – before and after the trial, which lasted 16 weeks. The team then worked with members of the Turnbaugh lab to analyze the data and to transplant the samples into mice that had been raised in sterile environments.

The researchers allowed these mice to continue eating the same amount of food and found, to their surprise, that the rodents that had received a transplant of the post-diet microbiome lost weight.

“We drove weight loss just by colonizing these mice with a different microbial community,” Turnbaugh said.

The next step was to identify bacteria that could be responsible for the weight loss. To do that, Jordan Bisanz, PhD, a former postdoctoral fellow in the Turnbaugh lab and a first author on the study, sequenced the gut microbiomes of the test mice and compared them to those of control mice.

Bisanz discovered a bacterial factor behind changes in weight the team had observed: higher levels of C. difficile.

In the gut, C. difficile is associated with the process of fat metabolism. Initially, fats are digested with the help of bile salts. These bile salts are then broken down by bacteria other than C. difficile, producing what are called secondary bile salts. These bacterial metabolites keep the growth of C. difficile under control. In other words, people who are eating less, particularly less fat, can produce less bile, which in turn leads to fewer secondary bile acids and less of a check on the population of C. difficile.

“Ordinarily we would predict increased inflammation or even colitis following an increase in C. difficile,” said Turnbaugh, who is also an investigator at the Chan Zuckerberg Biohub, Curiously, when he and his team examined the mice, they found only mild inflammation. That lack of inflammation suggests that C. diff could have important effects on metabolism that are distinguishable from the bacterium’s ability to drive severe intestinal disease.

At the same time, Turnbaugh notes, it’s not at all certain what would happen if someone stayed on the diet for a longer period of time and whether that could result in a full-blown C. difficile infection, which can be life threatening if it gets out of control.

“Let’s be clear; we are definitely not promoting C. difficile as a new weight loss strategy,” said Turnbaugh. “We’ve got a lot of biology left to unpack here.” The data raise a lot of interesting and unexplored questions about what role C. difficile is playing beyond the severe inflammatory conditions associated with it, he said.

It’s important to understand whether diet-induced changes to C. difficile level are harmful in humans, and how the balance between different microbial species in the gut is affected by different dietary choices, Turnbaugh said. Ultimately, that knowledge could allow clinicians to add or remove specific microbes in a patient’s gut to help maintain a healthy body weight.

“Multiple lines of research shows that the gut microbiome can either hinder or enhance weight loss,” said Turnbaugh. “We want to better understand how common weight loss diets might impact the microbiome and what the downstream consequences are for health and disease.”

Additional UCSF authors include Peter Spanogiannopoulos, Qi Yan Ang, Su-Yang Liu, Danielle Ingebrigtsen, Steve Miller, Jessie A. Turnbaugh, and Katherine S. Pollard. Pollard is also affiliated with the Gladstone Institutes.

The study was funded by grants from the National Institutes of Health (R01HL122593; R21CA227232; P30DK098722; 1R01AR074500; 1R01DK114034) among others. For additional funding and authorship information, please see the study.

Featured image: Peter Turnbaugh, Ph.D. © UCSF

Reference: von Schwartzenberg, R.J., Bisanz, J.E., Lyalina, S. et al. Caloric restriction disrupts the microbiota and colonization resistance. Nature (2021). https://doi.org/10.1038/s41586-021-03663-4

Provided by UCSF

Starting the Day Off With Chocolate Could Have Unexpected Benefits (Food)

Researchers find time of day eating milk chocolate can impact regulation of body weight

WHO Frank A. J. L. Scheer, PhD, MSc, Neuroscientist and Marta Garaulet, PhD, Visiting Scientist, both of the Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women’s Hospital. Drs. Scheer and Garaulet are co-corresponding authors of a new paper published in The FASEB Journal.

WHAT Eating milk chocolate every day may sound like a recipe for weight gain, but a new study of postmenopausal women has found that eating a concentrated amount of chocolate during a narrow window of time in the morning may help the body burn fat and decrease blood sugar levels.

To find out about the effects of eating milk chocolate at different times of day, researchers from the Brigham collaborated with investigators at the University of Murcia in Spain. Together, they conducted a randomized, controlled, cross-over trial of 19 postmenopausal women who consumed either 100g of chocolate in the morning (within one hour after waking time) or at night (within one hour before bedtime). They compared weight gain and many other measures to no chocolate intake.

Researchers report that among the women studied:

  • Morning or nighttime chocolate intake did not lead to weight gain;
  • Eating chocolate in the morning or in the evening can influence hunger and appetite, microbiota composition, sleep and more;
  • A high intake of chocolate during the morning hours could help to burn fat and reduce blood glucose levels.
  • Evening/night chocolate altered next-morning resting and exercise metabolism.

“Our findings highlight that not only ‘what’ but also ‘when’ we eat can impact physiological mechanisms involved in the regulation of body weight,” said Scheer.

“Our volunteers did not gain weight despite increasing caloric intake. Our results show that chocolate reduced ad libitum energy intake, consistent with the observed reduction in hunger, appetite and the desire for sweets shown in previous studies,” said Garaulet.

Featured image credit: Screen Moment/Stocksy United

Reference: Hernández-González, T, González-Barrio, R, Escobar, C, et al. Timing of chocolate intake affects hunger, substrate oxidation, and microbiota: A randomized controlled trial. The FASEB Journal. 2021; 35:e21649. https://doi.org/10.1096/fj.202002770RR

Provided by Brigham and Women’s Hospital

Weight-loss Maintainers Sit Less Than Weight-stable People With Obesity (Physiology)

People who are successful at weight-loss maintenance spend less time sitting during the week and weekends compared to weight-stable individuals with obesity, according to a paper published online in Obesity, The Obesity Society’s flagship journal. This is the first study to examine time spent in various sitting activities among weight-loss maintainers.

Prior findings from 2006 in the National Weight Control Registry indicated that weight-loss maintainers watched significantly less television than controls, but other sitting activities were not examined. In the current study, weight-loss maintainers did not significantly differ from controls in reported weekly sitting time spent watching television, but did differ in time spent in non-work-related time using a computer or video game.

Differences between the current study and National Weight Control Registry findings could reflect changes over the past 15 years in available electronic devices, including the rise in availability of computers and video games. Weight-loss maintainers and controls also did not appreciably differ in time spent sitting while reading or studying, traveling; or talking, texting and socializing. These could be considered more mentally active forms of sedentary behavior.

“The findings hopefully will prompt future weight maintenance intervention research testing the effects of and optimal approaches for reducing sedentary behavior, including non-work-related computer and video game usage. Future research should include objective measures of sedentary behavior and activity,” said Suzanne Phelan, Department of Kinesiology and Public Health and The Center for Health Research, California Polytechnic State University, in San Luis Obispo. Phelan is the corresponding author of the study.

Participants in the study included 4,305 weight-loss maintainers from WW (formerly Weight Watchers) who had maintained >9.1 kg of weight loss (24.7 kg on average) for 3.3 years and had an average current BMI of 27.6 kg/m2. The group of weight-stable individuals with obesity had an average BMI of 38.9 kg/m2. To gather data, the Multicontext Sitting Time and Paffenbarger physical activity questionnaires were administered.

Results revealed that weight-loss maintainers versus weight-stable individuals with obesity spent three hours less per day sitting during the week (10.9 versus 13.9) and weekends (9.7 versus 12.6). Weight-loss maintainers compared with controls also spent one hour less per day in non-work-related sitting using a computer or playing a video game during the week (1.4 versus 2.3) and weekends (1.5 versus 2.5). There were no meaningful differences between weight-loss maintainers and weight-stable individuals with obesity in the number of television sets and sedentary-promoting devices in the home (15.8 versus 14.8). Weight-loss maintainers expended significantly more calories per week in physical activity (1,835 versus 785).

“These findings are important for understanding behaviors that may enhance weight loss maintenance, and one of those may be to reduce sitting time and other modes of sedentary behavior. However, this study also showed that physical activity was associated with improved weight-loss maintenance. Thus, this study does not imply that simply standing more rather than sitting will contribute to weight-loss maintenance, but may suggest that less sitting that results in more movement is what is key to weight loss maintenance. Hence, sit less and move more,” said John M. Jakicic, PhD, FACSM, FTOS, Distinguished Professor, and Director of the Healthy Lifestyle Institute and the Physical Activity and Weight Management Research Center at the University of Pittsburgh in Pennsylvania. Jakicic was not associated with the research.

Other authors of the study include James Roake, Noemi Alarcon and Sarah Keadle of the Department of Kinesiology and Public Health and The Center for Health Research, California Polytechnic State University, in San Luis Obispo. Chad Rethorst of Texas A&M Agrilife in Dallas, Texas and Gary Foster of WW International, Inc. of New York and the Center for Weight and Eating Disorders, Perelman School of Medicine, University of Pennsylvania, in Philadelphia also co-authored the study.

The paper, titled “Sitting Time, Type, and Context Among Long-Term Weight-Loss Maintainers“, will be published in the June 2021 print issue.

This research was supported by a grant from WW International, Inc.

Phelan reports receiving a research grant from WW International, Inc. Foster is an employee and shareholders of WW. At the time of the study, Rethorst was an employee and shareholder of WW. The remaining authors declared no conflicts of interest.

Provided by The Obesity Society

Researchers Find the Secret Behind Maintaining A Healthy Weight Loss (Medicine)

Almost one in five Danes live with obesity, which may have serious health consequences. In the world’s most recognized medical journal, Danish researchers now document how to effectively achieve and maintain a healthy weight loss.

Half of the Danish population have overweight, while 17 percent live with obesity. The condition is associated with increased risk for early death, as well as sequelae such as Type 2 diabetes, cardiovascular diseases, cancer, and infertility.

Weight regain after an initial successful weight loss in people with obesity, constitutes an important and unsolved problem. Until now, no well-documented study on which treatment method is best for maintaining a healthy weight loss has been available.

Researchers at University of Copenhagen and Hvidovre Hospital have completed a new, sensational study, which is being published in the world’s most quoted medical journal, The New England Journal of Medicine. By testing four different types of treatment following a diet-induced weight loss, the researchers demonstrate for the first time how it is possible for people with obesity to maintain long-term weight loss, says Professor Signe Torekov at the Department of Biomedical Sciences.

In a randomized clinical trial, the group of researchers has demonstrated a highly effective treatment after a diet-induced weight loss, by combining moderate to vigorous-intensive exercise with appetite-inhibiting obesity medication, an analogue to the appetite-inhibiting hormone GLP-1.

“This is new knowledge for doctors, dietitians and physical therapists to use in practice. This is evidence that we have been missing,” explains Signe Torekov, who has been heading the study.

“The problem is that people are fighting against strong biological forces when losing weight. The appetite increases simultaneously with decreased energy consumption, and this counteracts weight loss maintenance. We have an appetite-stimulating hormone, which increases dramatically when we lose weight, and simultaneously the level of appetite-suppressing hormones drops dramatically. In addition, a weight loss can provoke loss of muscle mass, while the body reduces the energy consumption. Thus, when the focus in obesity treatment has been on how to obtain a weight loss – rather than how to maintain a weight loss – it is really difficult to do something about your situation,” says Signe Torekov.

Highly efficient when combining treatments

215 Danes with obesity and low fitness ratings participated in the study. The participants initially followed a low calorie diet over eight weeks, where they each lost approximately 13 kg, which brought significant improvements to their health with a drop in blood sugar level and blood pressure.

The participants were then randomly divided into four groups. Two of the groups received placebo medication, while the two other groups received obesity medication. Among the two placebo groups, one group followed an exercise program of minimum 150 minutes of physical activity at moderate intensity or 75 minutes at vigorous-intensity during the week or a combination of the two, while the other group maintained their current level of physical activity. The two groups receiving obesity medication were similarly divided into one group with and one group without an exercise program.

All participants in the study were weighed monthly and received nutritional and diet counseling with the focus on healthy weight loss according to the guidelines from the Danish health and food administrations.

After one year, the group with exercise alone and the group with obesity medication alone maintained the weight loss of 13 kg and health improvements. The placebo group gained half of the weight back with deterioration of all risk factors, for example for development of Type 2 diabetes and cardiovascular disease.

Graf 1
Illustration: Karina Kjærgård Kranker.

The most dramatic improvements occurred in the combination group, which followed the exercise program and received obesity medication. The researchers observed additional weight loss in this group, and the total weight loss was approximately 16 kg over one year. The health benefits were also double that of each of the single treatments, i.e., twice the loss of fat mass while preserving muscle mass, higher fitness ratings, reduced blood sugar and improved quality of life.

The two groups that exercised increased their fitness rating, lost fat mass, and gained muscle mass. This could indicate a healthier weight loss than for people, who had only lost fat mass without increasing the fitness rating.

“It is an important aspect to highlight, as you do not necessarily get a healthier body from losing weight if, at the same time, you lose a lot of muscle mass,” says Signe Torekov.

“It is great news for public health that a significant weight loss can be maintained with exercise for approximately 115 minute per week performed mostly at vigorous-intensity, such as cycling.  And that by combining exercise with obesity medication, the effect is twice as good as each of the individual treatments”.”

With the study, the researchers now hope people with obesity, together with their care provider, can create a useful framework for maintaining the weight loss.

Graf 2
Illustration: Karina Kjærgård Kranker.

Fundamental lifestyle change

Signe Torekov points out that many people with obesity have tried to lose weight before, only to regain the weight. This happens, because the general advice is to eat healthier and exercise more.

“Without a follow-up on whether people actually have support to perform exercise, the treatment will not be enough. Therefore, we also followed up with the participants on an ongoing basis to ensure that they received the support they needed in order to exercise. That is necessary, because maintaining weight loss is extremely hard. People need to understand this. Once you have lost weight, you are not “cured”. “The ongoing exercise and effort will likely need to continue for many years,” says Signe Torekov.

“Our study also demonstrates that without a structured treatment plan, there is a high risk of gaining the weight back. There were 12 individual consultations over the course of a year, including weighing and diet advice from Danish authorities according to guidelines for healthy weight maintenance. This was just not enough for the placebo group without exercise program, in this group all health benefits gained by weight loss during the eight week program were gone after one year, despite frequent weighing and diet and nutritional counseling based on official guidelines”. Torekov says.

According to Signe Torekov, this underscores the importance of participating in a mutual weight maintenance program based on feedback when starting a weight loss programme.

“Therefore, it is important that there is a system for supporting people with obesity in maintaining the lifestyle change. Our study can help with this, because we can say this actually works to doctors, dietitians and municipalities, if they create a structured, joint treatment plan with the individual using ongoing follow-ups,” says Torekov.

Read the full study here.

Featured image credit: Colorbox

Reference: Julie R. Lundgren, M.D., Ph.D., Charlotte Janus, Ph.D., Simon B.K. Jensen, M.Sc., Christian R. Juhl, M.D., et al., “Healthy Weight Loss Maintenance with Exercise, Liraglutide, or Both Combined”, N Engl J Med 2021; 384:1719-1730
DOI: 10.1056/NEJMoa2028198

Provided by University of Copenhagen

Weight Loss Surgery Reduces Brain Pressure In Patients With Increasingly Common Neurological Condition (Neuroscience)

Weight loss surgery is more effective than dieting to reduce brain pressure that can cause blindness in patients with a neurological condition, finds a study led by the University of Birmingham and University Hospitals Birmingham NHS Foundation Trust (UHB).

Idiopathic Intracranial Hypertension (IIH) is a debilitating condition that raises pressure in the brain and can lead to chronic headaches and even permanent sight loss. The illness, which often leaves patients with a reduced quality of life, predominately affects women aged 25 to 36 and weight gain is a major risk factor of developing IIH and relapses of the disease.

Weight loss has been shown to be an effective treatment, with a reduction in body weight of between three to 15% inducing disease remission. However, maintaining weight loss is notoriously difficult, as most patients regain weight over a two to five year period.

In the first clinical trial of its kind, the research team set out to analyse whether bariatric surgery or a 12-month community weight management intervention (delivered through Weight WatchersTM) would be the most effective for reducing brain pressure in women with IIH.

The trial, supported by the National Institute for Health Research (NIHR), involved 66 women with IIH with an average age of 32 years and a body mass index (BMI) of 35 or more. Half underwent bariatric surgery, while the other half took part in Weight WatchersTM. Brain pressure was measured by lumbar puncture at the start and after 12 and 24 months.

The results, published today in JAMA Neurology, showed that bariatric surgery was significantly more effective than community weight management, with those having had surgery seeing an average intracranial pressure reduction of 25% after 12 months.

The results also showed that the surgery group lost on average 23Kg, as compared to losing 2kg in the Weight WatchersTM group at 12 months. This difference was greater at 24 months with 24% more weight lost in the surgery group as compared to Weight WatchersTM. This was because the bariatric surgery group continued to lose more weight over time (28Kg from the start of the study to 2 years), whilst the community weight management group had regained weight lost and, on average, were only 1kg lighter than at the start of the study.

Senior author Alex Sinclair, Professor of Neurology at the University of Birmingham and Neurology lead of the Idiopathic Intracranial Hypertension Service at UHB, said: “A link between weight and IIH has long been observed but, until now, there has been no robust evidence that weight loss can reduce brain pressure.

“We have shown that weight loss achieved through bariatric surgery is significantly more therapeutic than community weight loss management interventions both in the short and longer term to treat IIH brain pressure.

“Whilst we recognise that bariatric surgery may not be an appropriate approach for all patients with IIH and increased weight, it is important to now have the evidence that a surgical approach can lead to significant sustained disease remission.”

First author Miss Susan Mollan, Director of Ophthalmic Research at UHB, added: “We hope that as a consequence of this research, current NHS and NICE guidance can change to include bariatric surgery as a treatment for women with IIH and a BMI greater than 35 when appropriate and in line with the patient’s best interests and wishes.

“Weight stigma is a major barrier to patient care in IIH. We also hope this research will prompt discussion and education around weight management to ensure this sensitive topic is approached with care and dignity.”

Co-author James Mitchell, Lecturer in Neurology at the University of Birmingham, added: “Weight regain is often driven by biology rather than willpower, and obesity is a chronic relapsing disease that requires lifelong treatment. Therefore, it’s essential that patients are given appropriate support to achieve weight loss and further work is done to ensure they have good access to weight management services.”


  • Mollan et al (April, 2021). ‘Bariatric surgery versus community weight management intervention for the treatment of idiopathic intracranial hypertension (IIH:WT): A randomized clinincal trial.’ JAMA Neurology. DOI: 10.1001/jamanerol.2021.0659

Provided by University of Birmingham

An Avocado A Day Keeps Your Gut Microbes Happy (Food)

Eating avocado as part of your daily diet can help improve gut health, a new study from University of Illinois shows. Avocados are a healthy food that is high in dietary fiber and monounsaturated fat. However, it was not clear how avocados impact the microbes in the gastrointestinal system or “gut.”

Adding avocado to your meal improves gut health, a new University of Illinois study shows. © College of ACES, University of Illinois.

“We know eating avocados helps you feel full and reduces blood cholesterol concentration, but we did not know how it influences the gut microbes, and the metabolites the microbes produce,” says Sharon Thompson, graduate student in the Division of Nutritional Sciences at U of I and lead author on the paper, published in the Journal of Nutrition.

The researchers found that people who ate avocado every day as part of a meal had a greater abundance of gut microbes that break down fiber and produce metabolites that support gut health. They also had greater microbial diversity compared to people who did not receive the avocado meals in the study.

“Microbial metabolites are compounds the microbes produce that influence health,” Thompson says. “Avocado consumption reduced bile acids and increased short chain fatty acids. These changes correlate with beneficial health outcomes.”

The study included 163 adults between 25 and 45 years of age with overweight or obesity – defined as a BMI of at least 25 kg/m2 – but otherwise healthy. They received one meal per day to consume as a replacement for either breakfast, lunch, or dinner. One group consumed an avocado with each meal, while the control group consumed a similar meal but without the avocado. The participants provided blood, urine, and fecal samples throughout the 12-week study. They also reported how much of the provided meals they consumed, and every four weeks recorded everything they ate.

While other research on avocado consumption has focused on weight loss, participants in this study were not advised to restrict or change what they ate. Instead they consumed their normal diets with the exception of replacing one meal per day with the meal the researchers provided.

The purpose of this study was to explore the effects of avocado consumption on the gastrointestinal microbiota, says Hannah Holscher, assistant professor of nutrition in the Department of Food Science and Human Nutrition at U of I and senior author of the study.

“Our goal was to test the hypothesis that the fats and the fiber in avocados positively affect the gut microbiota. We also wanted to explore the relationships between gut microbes and health outcomes,” Holscher says.

Avocados are rich in fat; however, the researchers found that while the avocado group consumed slightly more calories than the control group, slightly more fat was excreted in their stool.

“Greater fat excretion means the research participants were absorbing less energy from the foods that they were eating. This was likely because of reductions in bile acids, which are molecules our digestion system secretes that allow us to absorb fat. We found that the amount of bile acids in stool was lower and the amount of fat in the stool was higher in the avocado group,” Holscher explains.

Different types of fats have differential effects on the microbiome. The fats in avocados are monounsaturated, which are heart-healthy fats.

Soluble fiber content is also very important, Holscher notes. A medium avocado provides around 12 grams of fiber, which goes a long way toward meeting the recommended amount of 28 to 34 grams of fiber per day.

“Less than 5% of Americans eat enough fiber. Most people consume around 12 to 16 grams of fiber per day. Thus, incorporating avocados in your diet can help get you closer to meeting the fiber recommendation,” she notes.

Eating fiber isn’t just good for us; it’s important for the microbiome, too, Holscher states. “We can’t break down dietary fibers, but certain gut microbes can. When we consume dietary fiber, it’s a win-win for gut microbes and for us.”

Holscher’s research lab specializes in dietary modulation of the microbiome and its connections to health. “Just like we think about heart-healthy meals, we need to also be thinking about gut healthy meals and how to feed the microbiota,” she explains.

Avocado is an energy-dense food, but it is also nutrient dense, and it contains important micronutrients that Americans don’t eat enough of, like potassium and fiber.

“It’s just a really nicely packaged fruit that contains nutrients that are important for health. Our work shows we can add benefits to gut health to that list,” Holscher says.

References: Sharon V Thompson, Melisa A Bailey, Andrew M Taylor, Jennifer L Kaczmarek, Annemarie R Mysonhimer, Caitlyn G Edwards, Ginger E Reeser, Nicholas A Burd, Naiman A Khan, Hannah D Holscher, Avocado Consumption Alters Gastrointestinal Bacteria Abundance and Microbial Metabolite Concentrations among Adults with Overweight or Obesity: A Randomized Controlled Trial, The Journal of Nutrition, , nxaa219, https://doi.org/10.1093/jn/nxaa219

Provided by College of Agricultural, Consumer & Environmental Sciences – University of Illinois

Gastric Bypass Surgery Leads to Long-term Diabetes Remission (Medicine)

More than half of adults with type 2 diabetes had long-term remission following gastric bypass surgery, according to a new study published in the Endocrine Society’s Journal of Clinical Endocrinology & Metabolism.

©Science photo library

Bariatric surgery helps people with severe obesity lose a lot of weight and improve their health. Two common types of bariatric surgery are lap band surgery, which places a band around the top of the stomach to create a very small pouch that can hold only a small amount of food, and gastric bypass, which reduces the size of the stomach, causes hormonal changes, and can lower the amount of nutrients that are absorbed from food. One of the biggest benefits of bariatric surgery is that it can improve or eliminate type 2 diabetes.

“If a patient with type 2 diabetes is considering weight loss surgery, choosing gastric bypass soon after diagnosis can increase their chance of remission or achieving a blood sugar level that does not need treatment,” said study author Jonathan Q. Purnell, M.D., of the Oregon Health & Science University in Portland, Ore. “Our large study confirms the importance of weight loss on inducing diabetes remission, but also finds gastric bypass has benefits independent of weight. If we can understand what these benefits are, it could lead to new diabetes treatments.”

The researchers studied 2,256 adults with severe obesity (a BMI of at least 35 kg/m²) who completed annual research assessments for up to seven years after bariatric surgery, roughly 35 percent of whom had type 2 diabetes. Fifty seven percent of participants with diabetes achieved remission after gastric bypass surgery, and 22 percent reached remission after lap band surgery. For both procedures, remission was more common in younger participants and those who had diabetes for a shorter time prior to their procedure. The researchers found a greater likelihood of diabetes remission after gastric bypass independent of weight loss, suggesting mechanisms beyond weight loss are contributing to improved blood sugar levels.

References: Jonathan Q Purnell, MD, Elizabeth N Dewey, MS, Blandine Laferrère, MD, Faith Selzer, PhD, David R Flum, MD, MPH, James E Mitchell, MD, Alfons Pomp, MD, Walter J Pories, MD, Thomas Inge, MD, PhD, Anita Courcoulas, MD, Bruce M Wolfe, MD, Diabetes Remission Status During Seven-year Follow-up of the Longitudinal Assessment of Bariatric Surgery Study, The Journal of Clinical Endocrinology & Metabolism, , dgaa849, https://academic.oup.com/jcem/advance-article/doi/10.1210/clinem/dgaa849/6006261 https://doi.org/10.1210/clinem/dgaa849

Provided by The Endocrine Society

Popular Weight-loss Surgery in Teenagers Weakens Bones (Medicine)

“Childhood obesity is a major public health issue that has increased over the last 10 years,” said lead investigator Miriam A. Bredella, M.D., professor of radiology at Harvard Medical School in Boston, Massachusetts, and vice chair of the Department of Radiology at Massachusetts General Hospital in Boston. “Sleeve gastrectomy is the most common bariatric surgery procedure performed in children and adults.”

CT in a 17-year-old female prior to sleeve gastrectomy. Volumetric bone mineral density pre-surgery was 183 mg/cm³. ©Radiological Society of North America

In a sleeve gastrectomy, approximately 75% of the stomach is removed to restrict food intake and induce weight loss. It results in a typically round stomach taking on the shape of a tube or sleeve. The number of sleeve gastrectomy procedures performed on adolescents increased 100-fold from 2005 to 2014.

“In adults, bariatric surgery can have long-term effects on bone, leading to higher fracture risk,” Dr. Bredella said. “We wanted to determine the effects of sleeve gastrectomy performed on adolescents during the crucial years when bone mass is being accrued.”

The study examined 52 adolescents with moderate to severe obesity, 26 of whom underwent sleeve gastrectomy. The other 26 were in the control group. Mean age was 17.5 years, and mean body mass index (BMI) was 45. BMI of 30 or above is considered obese. Thirty-eight of study participants were girls. Before and 12 months after sleeve gastrectomy (or no surgery), the patients underwent quantitative CT of the lumbar spine, to quantify volumetric bone mineral density. Quantitative CT is a highly accurate technique for detecting changes in volumetric bone mineral density after extreme weight loss.

Recent studies have shown that bone marrow fat responds to changes in nutrition and may serve as a biomarker for bone quality. Therefore, patients underwent proton MR spectroscopy to quantify bone marrow fat of the lumbar spine.

One year following surgery, the adolescents who underwent sleeve gastrectomy lost 34 (+/-13) kg, or 75 (+/-28) pounds, while there was no significant change in weight in the control group. Compared to the controls, sleeve gastrectomy patients had a significant increase in bone marrow fat and a decrease in bone density in the lumbar spine.

“Adolescents who underwent sleeve gastrectomy had bone loss and an increase in bone marrow fat, despite marked loss of body fat,” Dr. Bredella said. “While weight-loss surgery is successful for weight loss and improving metabolic disorders, it has negative effects on bone.”

Dr. Bredella said the loss of bone density following sleeve gastrectomy was expected because greater weight-bearing strengthens bones. In addition to a loss of bone density, other effects of weight-loss surgery include a disruption of hormones and nutrients important for bone health.

“We need to identify mechanisms that will help prevent bone loss in these patients and to make adolescents with obesity more aware of bone health,” she said. “Adolescence is the critical time for bone mass accrual, and any process that interferes with bone accrual during this time can have dire consequences later in life.”

Provided by RSNA

Calories By The Clock? Squeezing Most Of Your Calories In Early Doesn’t Impact Weight Loss (Medicine)

Research Highlights:

* Time-restricted eating, which restricts eating to specific hours of the day, did not impact weight among overweight adults with prediabetes or diabetes.
* Adults in the 12-week study ate the same healthy, pre-prepared foods, however, one group ate the bulk of their calories before 1 p.m. each day, versus the other group that ate 50% of their calories after 5 p.m.

Restricting meals to early in the day did not affect weight among overweight adults with prediabetes or diabetes, according to preliminary research to be presented at the American Heart Association’s Scientific Sessions 2020. The meeting will be held virtually, Friday, November 13 – Tuesday, November 17, 2020, and is a premier global exchange of the latest scientific advancements, research and evidence-based clinical practice updates in cardiovascular science for health care worldwide.

“We have wondered for a long time if when one eats during the day affects the way the body uses and stores energy,” said study author Nisa M. Maruthur, M.D., M.H.S., associate professor of medicine, epidemiology and nursing at Johns Hopkins University in Baltimore. “Most prior studies have not controlled the number of calories, so it wasn’t clear if people who ate earlier just ate fewer calories. In this study, the only thing we changed was the time of day of eating.”

Maruthur and colleagues followed 41 overweight adults in a 12-week study. Most participants (90%) were Black women with prediabetes or diabetes, and average age of 59 years. Twenty-one of the adults followed a time-restricted eating pattern, limiting eating to specific hours of the day and ate 80% of their calories before 1 p.m. The remaining 20 participants ate at usual times during a 12-hour window, consuming half of their daily calories after 5 p.m. for the entire 12 weeks. All participants consumed the same pre-prepared, healthy meals provided for the study. Weight and blood pressure were measured at the beginning of the study; then at 4 weeks, 8 weeks and 12 weeks.

The analysis found that people in both groups lost weight and had decreased blood pressure regardless of when they ate.

“We thought that the time-restricted group would lose more weight,” Maruthur said. “Yet that didn’t happen. We did not see any difference in weight loss for those who ate most of their calories earlier versus later in the day. We did not see any effects on blood pressure either.”

The researchers are now collecting more detailed information on blood pressure recorded over 24 hours, and they will be compiling this information with the results of a study on the effects of time-restricted feeding on blood sugar, insulin and other hormones.

“Together, these findings will help us to more fully understand the effects of time-restricted eating on cardiometabolic health,” Maruthur said.

Co-authors are Scott Pilla, M.D., M.H.S.; May T.T. Maw, M.B.B.S.M., M.P.H.; Daisy Duan, M.D.; Di Zhao, Ph.D.; Eliseo Guallar, M.D., Dr. P.H.; Ruth Alma Turkson Ocran, Ph.D.; Karen White, M.S.; Beiwen Wu, M.S.P.H.; Jeanne Charleston, R.N.; Lawrence J. Appel, M.D., M.P.H.; and Jeanne M. Clark, M.D., M.P.H. Author disclosures are in the abstract. The study was funded by a grant from the American Heart Association.

Additional Resources:

Multimedia, including a video perspective interview with Alexis C. Wood, Ph.D., chair of the writing group for the American Heart Association Scientific Statement: Caregiver Influences on Eating Behaviors in Young Children (May 2020), may be downloaded from the right column of the release link https://newsroom.heart.org/news/calories-by-the-clock?preview=b6fd89ef6b6c8a9bf6d448a9bf3ab580

Provided by American Heart Association