SHR

There are many benefits to be gained from exercise and weight loss in the overweight-obese population, and both are commonly prescribed to achieve cardiometabolic health improvements. However, exercise for weight loss is an inefficient and unsustainable route for many individuals. Instead, exercise should be done for health while weight loss is achieved through dietary modifications. But which has a greater impact? The answer comes from the University of Copenhagen, Denmark who recently published additional data from the CUT-IT study where 64 overweight-obese out-patients (age 45-75 years) with coronary artery disease (CAD) were randomized to undergo 12 weeks of aerobic interval training (AIT) three times weekly or consume a low-energy diet (LED) for 8-10 weeks followed by 2-4 weeks of transition to a high-protein/low-glycemic index diet. The AIT protocol involved a 38 minute session beginning with a 10-minute moderate-intensity warm-up followed by high intensity interval training (85-90% of VO2peak, Borg scale 17–18) on...

Metabolically healthy obese – key protective factors Obesity is commonly accompanied by numerous comorbidities (metabolic syndrome) that involve insulin resistance (IR), type-2 diabetes (T2D), hypertension, dyslipidemia, cardiovascular diseases, and a systemic inflammatory state. However, not all obese adults have these conditions and there are in fact obese individuals who have less visceral fat and adverse health complications than would be expected, a condition that has been termed metabolically healthy obesity (MHO). Why are these people different? That is the central question answered by Goncalves et al, who reviewed the protective metabolic, genetic, and etiological factors of MHO that represent between 10% and 45% of the adult obese population. It turns out that everything is traceable to one seminal factor – lower visceral fat, which is what ultimately causes IR and the detrimental inflammatory and hormonal profile that contributes to increased risk for cardiovascular disease. Whether some individuals carry genetic predisposition to MHO,...

Individuals suffering from type-2 diabetes (T2D) can have a grocery list of health problems secondary to their condition, but the core issue is a dysregulation of glucose metabolism. The cause is multi-faceted and includes both genetic and environmental factors, but one consistently reappearing player is an excess amount of fat tissue – especially visceral fat. Therefore, it stands to reason that fat loss in individuals with T2D would lead to improvements in glucose metabolism. To test this hypothesis, researchers from the Mayo Clinic College of Medicine recruited 9 morbidly obese individuals with T2D (7 female) to follow a very low-calorie diet for 12-weeks. The diet consisted of 740 kcal daily for the first 4 weeks and 875 kcal daily thereafter, with meals derived from the Nutritional Guidelines for Bariatric Surgery. The participants met with a dietitian weekly and a behavioral psychologist every other week to facilitate compliance. Body composition measurements (DXA...

Smoking is associated with increased resting energy expenditure Cigarette smoking is known to be associated with lower bodyweight and weight gain is a common feature of smoking cessation. It is believed that nicotine acts by various mechanisms on the body’s energy balance and affects both the central nervous system and peripheral tissues by regulating the release of a wide range of neurotransmitters and hormones. Now, Blauw et al show in the first large-scale cohort of its kind that smokers have a 4.7% higher resting energy expenditure per kilogram of fat-free mass than never smokers. This result came from analysis of 1189 men and women from the Netherlands Epidemiology of Obesity (NEO) study. Where do we get our protein? According to Pasiakos et al from the US Army Research Institute of Environmental Medicine, who analyzed the NHANES 2007-2010 data on 10,977 adults, the average protein intake from animal, dairy, and plants was...

Obesity, screen time, and sedentariness predict lower academic achievement in children Antonio Garcia-Hermoso and Raquel Marina recently recruited 395 seventh-grade boys and girls from seven schools to estimate the relationship between weight, physical activity, screen time, and academic achievement. After adjusting for several confounding variables, they found that boys and girls with obesity had worse grades than their leaner peers and that kids who had more than 2-hours of screen time daily had worse grades independent of weight status and physical activity. These associations only became stronger when variables were combined. Both boys and girls who were obese, with low–medium physical activity and exceeded recommended screen time were less likely to earn high academic achievements than their counterparts who were non-obese, with high physical activity and met screen time recommendations, independent of potential confounders. Have you ever wondered what infants in the U.S. eat? To say good nutrition during infancy is...

In 2012, researchers from Purdue University published a study suggesting that increasing total protein intake through whey protein supplementation was not effective in enhancing exercise-induced improvements in body composition and indices of metabolic syndrome in middle-aged overweight and obese adults. In this double-blind, randomized, placebo-controlled, community-based study, 220 inactive adults [about half of which had metabolic syndrome (MetS)] completed a 9-month resistance training (2 d/wk) and aerobic training (1 d/wk) exercise program that ultimately led to increases in whole-body strength and VO2max and an increase in lean-body mass (LBM) and reduction in fat mass (FM) despite no bodyweight change. However, during this intervention period, the participants were also instructed to consume a 200 kcal sachet twice daily with breakfast and lunch that contained 0, 10, 20, or 30 g whey protein (total daily supplemental dose 400 kcal and 0, 20, 40, and 60 g whey, respectively), which had no impact on...

Over the last decade, there has been a considerable amount of literature dedicated to clarifying the role that fructose plays in health and disease. Unlike glucose, fructose is primarily metabolized within the liver and bypasses a critical rate-limiting step (phosphofructokinase) in the energy production pathway of glucose. Bypassing this step means that the metabolism of fructose is less controlled than the metabolism of glucose, and this is the main reason why fructose and glucose have different metabolic effects. It has been shown in healthy adults that fructose stimulates DNL (de novo lipogenesis; the creation of fatty acids) to a greater extent than glucose, and this is the main reason why fructose has been portrayed as particularly harmful. However, isotopic tracer studies in humans suggest that 50% of ingested fructose is converted into glucose, 25% into lactate, at least 15% into liver glycogen, and only 10% oxidized directly or converted to fatty...

Adjectives are relative, and while I would not consider any obese person to be healthy in general, there is no doubt that some obese individuals are healthier than other obese individuals. This is no different from how some normal-weight people are going to be healthier than other normal-weight people. The divide between healthy and unhealthy is typically the criterion for metabolic syndrome, which requires that an individual possess three or more of the following: abdominal obesity, hypertension, low HDL-c, high triglycerides, and prediabetes. Taking medications to manage any of these conditions also counts. Regardless of weight, common sense tells us that someone without metabolic syndrome is going to be healthier in general than someone with metabolic syndrome, and meta-analyses support this for type-2 diabetes and cardiovascular disease and mortality. A question we might ask is why some people become metabolically unhealthy? Given the vast literature base supporting the health benefits of...

Are siblings to blame for body composition? This is a question that pondered in the minds of researchers from Brazil, who used data from a birth cohort in 1993 to evaluate the how the number of siblings in a family was related to body composition. Ultimately, 5249 mothers agreed to participate, and their children were assessed at ages 4, 6, 9, 11, 13 and 18 years with the Bod Pod. After adjustment for possible confounding variables, there was a significant association between the number of siblings and fat mass in both boys and girls, while only in girls was muscle mass was associated with sibling number. Boys who had more siblings were less fat and had a lower BMI, while girls with more siblings had less fat and more muscle. What are the “healthy” and “unhealthy” microbes? The human gut is home to trillions of microbes that outnumber the cells in...

Fasting can take a variety of forms. One such is alternate day fasting (ADF) in which individuals do exactly as the name states, alternate fasting and feeding days. Although this originally encompassed not eating for the entire day and creating a roughly 36 hour fast from dinner one night to breakfast two days after, a more prudent version involves only fasting until dinner the following day, about 24 hours. This form of ADF has a strong track record for aiding weight loss and reducing cardiometabolic risk in normal-weight and overweight-obese persons alike. However, although compliance in these and other trials has been exceptional with few reported adverse effects, concerns about the safety of ADF have yet to be directly addressed.