Tag: weight loss

Optimum Heart Rate for Fat Burning can Vary Widely among Individuals

The study uncovered individual variations in fat burning during exercise. Graphs of two people’s fat burning curves highlight differences in fat burning rates at varying exercise intensities and demonstrate that fatMAX falls outside the predicted ‘fat burning zone’. Credit: Hannah Kittrell, Mount Sinai Physiolab and AIMS Lab at Icahn Mount Sinai

The ‘fat burning zone’ on commercial exercise machines often does not line up the best heart rate for burning fat as it differs for each individual, Icahn School of Medicine at Mount Sinai researchers report.

Instead, the researchers said, clinical exercise testing (a diagnostic procedure to measure a person’s physiological response to exercise) may be a more useful tool to help individuals achieve intended fat loss goals. The study, which used a machine learning-based modelling approach, was published online in Nutrition, Metabolism and Cardiovascular Disease.

“People with a goal of weight or fat loss may be interested in exercising at the intensity which allows for the maximal rate of fat burning. Most commercial exercise machines offer a ‘fat-burning zone’ option, depending upon age, sex, and heart rate,” says lead author Hannah Kittrell, MS, RD, CDN, a PhD candidate at Icahn Mount Sinai. “However, the typically recommended fat-burning zone has not been validated, thus individuals may be exercising at intensities that are not aligned with their personalised weight loss goals.”

The term FATmax is sometimes used to represent the exercise intensity and associated heart rate at which the body reaches its highest fat-burning rate during aerobic exercise. At this point, fat is a significant fuel source and therefore this intensity may be of interest to those seeking to optimize fat loss during workouts.

As part of the study, the researchers compared heart rate at FATmax, as measured during a clinical exercise test, to predicted heart rate at percentages of maximal effort within the typically recommended ‘fat-burning zone’. In a sample of 26 individuals, the researchers found that there was poor agreement between measured and predicted heart rate, with a mean difference of 23 beats per minute between the two measures. This suggests that general recommendations for a ‘fat-burning zone’ may not provide accurate guidance.

Next, the researchers plan to study whether individuals who receive a more personalised exercise prescription demonstrate more weight and fat loss, as well as improvement of metabolic health markers that identify health risks like type 2 diabetes, obesity, and heart disease.

“We hope that this work will inspire more individuals and trainers to utilise clinical exercise testing to prescribe personalised exercise routines tailored to fat loss. It also emphasises the role that data-driven approaches can have toward precision exercise,” says senior author Girish Nadkarni, MD, MPH, Professor of Medicine at Icahn Mount Sinai.

Source: The Mount Sinai Hospital / Mount Sinai School of Medicine

Meal Skipping, Diet Prescription Pills Least Effective Weight Loss Habits

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A new study in the Journal of the American Heart Association links a healthier diet and increased exercise to weight loss that reduces heart disease risk – while associating skipping meals and taking prescription diet pills with minimal weight loss, weight maintenance or weight gain.

For many in the study sample of more than 20 000, losing a “clinically significant” 5% of their body weight did not eliminate their risk factors for cardiovascular disease, results showed. In fact, the average composite score on eight risk factors for heart disease was the same across the entirety of the study population – regardless of weight loss or gain.

The study is the first to compare weight-loss strategies and results in the context of the American Heart Association’s “Life’s Essential 8,” a checklist promoting heart disease risk reduction through the pursuit of recommended metrics for body weight, blood pressure, cholesterol, blood sugar, smoking, physical activity, diet and sleep.

The Ohio State University researchers found that overall, US adults had an average score of 60 out of 100 on the Essential 8 suggesting there is plenty of room for improvement even among those whose diet and exercise behaviours helped move the needle on some metrics.

“The Life’s Essential 8 is a valuable tool that provides the core components for cardiovascular health, many of which are modifiable through behaviour change,” said senior study author Colleen Spees, associate professor of medical dietetics in the School of Health and Rehabilitation Sciences at Ohio State.

“Based on the findings in this study, we have a lot of work to do as a country,” she said. “Even though there were significant differences on several parameters between the groups, the fact remains that as a whole, adults in this country are not adopting the Life’s Essential 8 behaviours that are directly correlated with heart health.”

Data for the analysis came from 20 305 U.S. adults aged 19 or older (average age of 47) who participated in the National Health and Nutrition Examination Survey (NHANES) between 2007 and 2016. Participants reported their smoking status, physical activity, average hours of sleep per night, weight history and weight loss strategy, and what they had eaten in the previous 24 hours. Health exams and lab tests measured their body mass index, blood pressure, LDL (bad) cholesterol and blood glucose.

The Ohio State researchers used the data to determine individuals’ values for Life’s Essential 8 metrics and assessed their diet quality according to the Healthy Eating Index, which gauges adherence to US Dietary Guidelines for Americans.

Of the sample, 17 465 participants had lost less than 5% of their body weight, maintained their weight or gained weight in the past year. The remaining 2840 reported intentional loss of at least 5% of their body weight in the same time frame.

“Clinically significant weight loss results in improvements in some health indices,” Spees said. “People should feel hopeful in knowing that losing just 5% of their body weight is meaningful in terms of clinical improvements. This is not a huge weight loss. It’s achievable for most, and I would hope that incentives people instead of being paralysed with a fear of failure.”

In this study, adults with clinically significant weight loss reported higher diet quality, particularly with better scores on intakes of protein, refined grains and added sugar, as well as more moderate and vigorous physical activity and lower LDL cholesterol than the group without clinically significant weight loss. On the other hand, the weight-loss group also had a higher average BMI and HbA1c blood sugar measure and fewer hours of sleep – all metrics that would bring down their composite Life’s Essential 8 score.

A greater proportion of people who did not lose at least 5% of their weight reported skipping meals or using prescription diet pills as weight-loss strategies. Additional strategies reported by this group included low-carb and liquid diets, taking laxatives or vomiting, and smoking.

“We saw that people are still gravitating to non-evidence-based approaches for weight loss, which are not sustainable. What is sustainable is changing behaviours and eating patterns,” Spees said.

Source: Ohio State University

Migraine Drug Could be Beneficial for Weight Loss

Obesity
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The commonly prescribed triptans, a class of migraine drugs, may be useful in treating obesity, a new study published in Journal of Experimental Medicine suggests. In studies on obese mice, a daily dose of a triptan caused them to eat less food and lose weight over the course of a month.

“We’ve shown that there is real potential to repurpose these drugs, which are already known to be safe, for appetite suppression and weight loss,” said study leader Chen Liu, PhD.

Serotonin has long been known to play a key role in appetite. However, there are 15 different serotonin receptors. Researchers have struggled to understand the role of each serotonin receptor in appetite, and previous drugs, including fen-phen and lorcaserin, that targeted certain individual receptors have been withdrawn from the market due to side effects.

Triptans, which are used to treat acute migraines and cluster headaches, work by targeting a different receptor — the serotonin 1B receptor (Htr1b) — that had not previously been well studied in the context of appetite and weight loss, said Dr Liu.

For the new study, the researchers tested six prescription triptans in obese mice that were fed a high-fat diet for seven weeks. Mice fed two of these drugs ate about the same amount, but mice fed the other four ate less. After 24 days, mice given a daily dose of the drug frovatriptan lost, on average, 3.6% of their body weight, while mice not given a triptan gained an average of 5.1% of their body weight. The researchers saw similar results when they implanted devices into the animals that gave them a steady dose of frovatriptan for 24 days.

“We found that these drugs, and one in particular, can lower body weight and improve glucose metabolism in less than a month, which is pretty impressive,” said Dr Liu.

Since triptans are generally prescribed for short-term use during migraines, Dr Liu suspects that patients would not have noticed the longer-term impacts on appetite and weight in the past.

To determine exactly how frovatriptan impacts food intake and weight, the researchers engineered mice to lack either Htr1b or Htr2c, the serotonin receptor targeted by fen-phen and lorcaserin. In mice without Htr1b, frovatriptan no longer could decrease appetite or cause weight loss, while cutting out Htr2c had no effect. This confirmed that the drug worked by targeting the serotonin 1B receptor.

“This finding could be important for drug development,” said Dr Liu. “We not only shed light on the potential to repurpose existing triptans but also brought attention to Htr1b as a candidate to treat obesity and regulate food intake.”

Source: UT Southwestern Medical Center

Financial Rewards are an Effective Weight Loss Motivator

Bathroom scale
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A large scale weight loss programme conducted with Australia’s national science agency, CSIRO, has demonstrated that personal accountability coupled with financial rewards continue to be a key motivator for successful weight loss.

The report [PDF] analysed data from over 48 000 CSIRO Total Wellbeing Diet members, more than triple the sample size from the original study in 2018. The authors found that those who successfully claimed the financial incentive offered by the programme, managed a 28% greater weight loss than those members who did not claim it.

Financial reward claimants lost an average of 6.2kg (or 6.7% of their starting body weight), versus the 4.8kg (or 5.2% of starting body weight) lost by those who did not claim the financial reward.

CSIRO Research Scientist and report author Dr Gilly Hendrie said the research was telling evidence of how taking personal accountability by engaging in self-monitoring behaviours promoted healthy weight loss.

“It is encouraging to see the results of our study support other psychology and behavioural change research that self-accountability and financial incentives can have a meaningful impact on people’s weight loss success,” Dr Hendrie said. 

“Breaking unhealthy habits that have developed over a long time can be hard and it is easy to lose motivation if you are not seeing immediate results on the scales.

“We’ve found self-accountability activities like tracking your weight and taking progress photos can be positive for members to see the physical changes from one week to the next; it can give them the drive to stay on track and continue to form the healthy habits which will help them achieve their health goals,” she said.

In addition, two thirds of members who claimed the reward lost a clinically relevant amount of weight, more than 5% of their starting body weight, compared to half of the non-rewarded members.

“A five per cent reduction in body weight is proven to markedly lower the risk for type 2 diabetes and cardiovascular disease and improve metabolic function in obese and overweight people,” Dr Hendrie said.

Programme participant Brian Thomas said he believes the refund reward was key to his 27 kg weight loss.

“The refund reward was not only a key motivator to me signing up, but it helped me achieve my weight loss goals and regain my health because it sets up the framework to do things you need to do to be successful,” Mr Thomas said.

“If I didn’t have to track my food for the refund reward, maybe I would never have got into the habit of tracking. Even now, three months after I received my refund, I’m still keeping up those behaviours. It’s allowed me to make positive changes to my own life and habits, and it has had a positive impact on my family.  Best of all it didn’t cost me a cent.”

The CSIRO Total Wellbeing Diet offers a financial reward equal to the cost of the program (AUS $199/R2 200) for people who complete the 12-week programme and follow the science-based criteria to make lifestyle changes for long-term weight loss. The criteria include weekly weigh-ins, uploading a photo to track progress, and using a food diary at least three times per week.

Source: CSIRO

Using The 5:2 Diet for Weight Loss in Gestational Diabetes

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In a welcome finding, researchers have found that women who have had gestational diabetes can use the popular 5:2 diet for weight loss to help prevent the onset of type 2 diabetes.   

It can be a challenge to lose weight and keep it off, especially for mothers with a new baby. The study by the University of South Australia suggests that the popular 5:2 or intermittent fasting diet is as effective as a conventional energy-restricting diet, giving women greater choice and flexibility for weight loss.

The 5:2 diet allows five days of normal eating each week while substantially restricting calories over two days a week, as opposed to a typical diet that requires moderate energy restrictions daily.

A fifth of pregnancies are affected by gestational diabetes, which carries a ten-fold risk of developing type 2 diabetes later in life, exacerbated even further by being overweight.

A welcome finding for a growing problem
The study’s lead researcher, Dr Kristy Gray, said women looking to lose weight will welcome the finding: “Gestational diabetes is the fastest growing type of diabetes in Australia, affecting 15% of pregnancies.

“Healthy eating and regular physical activity are recommended to manage gestational diabetes, with continuous energy restriction diets – or diets that cut calories by 25–30% being the most common strategy for weight loss and diabetes prevention.

“The trouble is, however, that new mums often put themselves last – they’re struggling with fatigue and juggling family responsibilities – so when it comes to weight loss, many find it hard to stick to a low-calorie diet.

“The 5:2 diet may provide a less overwhelming option. As it only cuts calories over two days, some women may find it easier to adopt and adhere to, as opposed to a consistently low-calorie diet requiring constant management.

“Our research shows that the 5:2 diet is just as effective at achieving weight loss as a continuous energy-restricted diet in women who have had gestational diabetes, which is great, because it provides women with greater choice and control,” she said, adding that women should seek advice from health professionals before starting the diet.

The research investigated the effects of both the 5:2 diet (five days eating normally and two days eating 500 calories) and a continuous energy-restricted diet (1500 calories per day) on weight loss and diabetes risk markers in women with a previous diagnosis of gestational diabetes. Both diets cut energy intake by about 25% a week.

The study was published in the American Journal of Clinical Nutrition.

Source: University of South Australia

GPs Should Aim for Diabetes Remission Through Weight Loss

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A large-scale review of clinical evidence concluded that achieving ‘remission’ for people with type 2 diabetes through dietary approaches and weight loss should be the primary treatment goal of GPs and healthcare practitioners.

Corresponding author Dr Duane Mellor at Aston University said: “Accounting for all the evidence, our review suggests remission should be discussed as a primary treatment goal with people living with type 2 diabetes. There are multiple dietary approaches that have been shown to bring about T2DM remission though at present meal replacements offer the best quality evidence. Low carbohydrate diets have been shown to be highly effective and should also be considered as a dietary approach for remission.”

Lead author, Dr Adrian Brown, UCL Division of Medicine said: “Traditionally T2DM has focussed on managing a person’s blood glucose with medication, however the approach doesn’t address the underlying causes of T2DM. There is now a growing body of research that shows losing significant weight, 10-15kg, either through weight loss surgery or dietary approaches, can bring about type 2 diabetes remission (non-diabetic blood sugar levels).”

Expert reviewers analysed over 90 research papers covering international clinical trials and clinical practice data of dietary methods used to treat T2DM. Their findings were published in the Journal of Human Nutrition & Dietetics.

The study found that meal-replacement diets helped 36% people successfully achieve remission, while low carbohydrate diets were able to help 17.6 % of people achieve and maintain remission for at least two years. People who lost the most weight and kept the weight off using both of these dietary approaches were able to stay in remission.

Calorie restricted and Mediterranean diets were somewhat less effective, with only about 5% of people on calorie restricted diets and 15% of people on a Mediterranean diet staying in remission after one year.

There were multiple definitions of ‘remission’: one is a return to non-diabetic blood sugar levels (glycated haemoglobin less than 48mmol/mol), without diabetes drugs. Other definitions however say weight (especially fat around the midsection) must be lost to achieve remission, and others allow medication to be used.

Some reports also suggested low-carbohydrate diets can normalise blood sugar levels even without weight loss, since carbohydrates cause blood sugar levels to rise. A low-carbohydrate diet means reduced blood sugar, leading to improved blood sugar control. However, if weight is lost without blood glucose being non-diabetic, the authors are suggesting this should instead be called mitigation, as the underlying mechanisms of T2DM are not being addressed.

Dr Brown said: “The evidence is clear that the main driver of remission remains the degree of weight loss a person achieved. Therefore, for those not achieving weight loss but achieving a non-diabetic blood glucose we are suggesting this isn’t remission per se, but rather ‘mitigation’ of their diabetes.”

The review concluded that while weight loss seems to best predict remission success, it assumes fat loss from the pancreas and liver. Future studies should compare how these diets work for different ethnic groups, as T2DM can occur at different body weights in different ethnic groups.

Dr Mellor added: “Not everyone will be able to achieve remission, but people who are younger (less than 50), male, have had type 2 diabetes for less than six years and lose more weight are more likely to be successful.”

Source: Ashton University

Weight Loss in 80% Following Series of Different Diets

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In a study testing three successive and varying diets, nearly 80 percent of participants in a lost a “clinically significant” amount of body weight in less than two years.

The participants adhered to a sequence of a calorie-restrictive diet, a low-carb/high-fat diet and an intermittent fasting diet, losing 11.1 kilograms on average.

The results were published in the journal Nutrition.

“Almost 80 percent of participants lost a clinically significant amount of weight,” said study leader Rebecca Christensen, a PhD candidate at the Dalla Lana School of Public Health. “This is important because losing just five percent of your body weight is associated with improvements in cardiometabolic function and other health concerns.

“That lets us know that we have a lot of different tools in the toolbox to pick from when initiating a dietary intervention.”

Christensen says that staying on the same diet can be tough, which is why she is pleased that the study’s findings suggest there may be an alternative.

“It can be quite hard for patients to maintain dietary interventions,” she said. “This might be where successive diets have an advantage as changing things up makes it easier to stick to a diet.”

As more people attempt to shed their pandemic weight, Christensen said she also found that there is no right month to start your diet. Rather, it is just about getting started, adding that reaching a very low body mass index (BMI) need not be the goal.

“We know that that’s not necessarily feasible,” she said. “But the very least they are reaching the weight that we know is beneficial for their health which is why we want to do the intervention.”

Source: University of Toronto

‘Game-changing’ Weight Loss Drug Semaglutide Approved by FDA

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The US Food and Drug Administration approved a ‘game changing’ weight loss drug called Wegovy (semaglutide) for chronic weight management in adults with obesity or overweight.

This injection is the first drug for chronic weight management in adults with general obesity or overweight to be approved since 2014. The drug is indicated for chronic weight management in patients with a body mass index (BMI) of 27 kg/m2 or greater who have at least one weight-related ailment or in patients with a BMI of 30 kg/m2 or greater, and is to be used in conjunction with diet and exercise.

“Today’s approval offers adults with obesity or overweight a beneficial new treatment option to incorporate into a weight management program,” said John Sharretts, MD, deputy director of the Division of Diabetes, Lipid Disorders, and Obesity in the FDA’s Center for Drug Evaluation and Research. “FDA remains committed to facilitating the development and approval of additional safe and effective therapies for adults with obesity or overweight.”

Approximately 70% of American adults have obesity or overweight, and >67% of sub-Saharan Africans. This is a serious health issue linked to leading causes of death such as heart disease, stroke and diabetes, and also to increased risk of certain types of cancer. Losing 5% to 10% of body weight through diet and exercise has been associated with a reduced risk of cardiovascular disease in adult patients with obesity or overweight.

Wegovy works by mimicking a hormone called glucagon-like peptide-1 (GLP-1) that targets areas of the brain regulating appetite and food intake. The medication dose must be increased gradually over 16 to 20 weeks to 2.4 mg once per week to reduce gastrointestinal side effects.

The drug’s safety and efficacy were studied in four 68-week trials. Over 2600 patients received Wegovy for up to 68 weeks in these four studies and more than 1500 patients received placebo.

The largest placebo-controlled trial enrolled diabetes free adults with an average age of 46 years, and 74% of whom were female. The average body weight was 105 kg and average BMI was 38 kg/m2. Individuals receiving Wegovy lost an average of 12.4% of their initial body weight compared to individuals who received placebo. Another trial enrolled adults with type 2 diabetes. The average age was 55 years and 51% were female, with an average body weight of 100 kg and average BMI of 36 kg/m2. In this trial, individuals receiving Wegovy lost 6.2% of their initial body weight compared to the placebo group.

“The approval of Wegovy in the US brings great promise to people with obesity. Despite the best efforts to lose weight, many people with obesity struggle to achieve and maintain weight loss due to physiological responses that favour weight regain,” said Martin Holst Lange, executive vice president, Development at Novo Nordisk. “The unprecedented weight loss for an anti-obesity medication marks a new era in the treatment of obesity, and we now look forward to making Wegovy available to people living with obesity in the US”.

Unfortunately, the drug may be out of the reach of many people in need of it, with indications being that the medication may be charged at around US$1,300 a month.

Source: Food and Drug Administration