Browse the evidence

Waist circumference (WC) is a superior predictor of metabolic risk and mortality in the elderly compared to Body Mass Index (BMI), which is confounded by age-related height loss and muscle loss.

Stop relying solely on BMI if you are over 65. Measure your waist circumference instead, as it better reflects the visceral fat that drives diabetes and heart disease risk in older age.

The doubly labelled water (DLW) method provides a highly accurate and precise measure of energy expenditure in free-living subjects, serving as a gold standard for validating energy intake assessments.

The doubly labelled water method is the gold standard for measuring energy expenditure in free-living subjects, but its high cost and complexity limit its routine use. Alternative validation methods like the EI/BMR ratio are available.

Physical inactivity is a major global health risk, ranking as the fourth leading cause of mortality and contributing to 3.2 million deaths annually, primarily through cardiovascular disease, diabetes, hypertension, and certain cancers.

Recognize that physical inactivity is a critical health risk, comparable to smoking or obesity. Prioritize increasing daily movement to reduce the risk of cardiovascular disease, diabetes, and hypertension. In Arab countries, be aware that cultural and gender-specific barriers may exist, requiring tailored solutions to overcome them.

Approximately 19% of the carbohydrate content from a mixed meal is stored as liver glycogen in healthy humans, with net synthesis continuing for up to 4 hours post-meal.

Your liver stores about 28 grams of glycogen from a typical mixed meal, which is about 19% of the carbs you ate. This storage process takes up to 4 hours. This is a normal, healthy storage mechanism, not fat gain.

Obesity is primarily driven by behavioral and environmental factors (sedentary lifestyle and excess energy intake) interacting with genetic susceptibility, rather than genetics alone.

Focus on your environment and habits, not just your genes. Reduce sedentary time and manage calorie intake, as these are the primary levers for weight change.

Muscle disuse leads to a decline in basal muscle protein synthesis and, in the early stages (<5 days), a transient increase in muscle protein breakdown, resulting in net muscle loss.

Understand that muscle loss starts immediately upon disuse. The body stops building muscle (synthesis drops) and may break it down faster for the first few days. This is why rapid intervention with nutrition (protein) and eventual retraining is critical to minimize permanent loss.

Mitochondrial impairment accelerates epigenetic aging, while enhancing mitochondrial biogenesis slows it, establishing a direct link between mitochondrial function and the rate of epigenetic aging.

Mitochondrial health is a key driver of epigenetic aging. Impairing mitochondria accelerates the epigenetic clock, while boosting mitochondrial biogenesis slows it. This suggests that interventions supporting mitochondrial function (like exercise or specific nutrients) may slow epigenetic aging, independent of DNA repair or telomere length.

Skeletal muscle is a key metabolic tissue responsible for ~80% of postprandial glucose disposal, and its circadian disruption contributes to insulin resistance and metabolic syndrome.

Prioritize muscle-building activities and regular physical activity to improve your body's ability to handle glucose after meals. Since muscles handle most of your post-meal sugar, stronger muscles can help prevent insulin resistance and type 2 diabetes.

The doubly labelled water (DLW) method is the gold standard for measuring total energy expenditure in free-living humans because it accurately captures activity energy expenditure without interfering with subject behavior.

If you need to know your true energy expenditure in daily life, self-reports and most wearables are unreliable. The doubly labelled water method is the only validated way to measure this accurately without restricting your normal activities, though it is primarily a research tool due to cost and complexity.

Fat-free mass-adjusted total and basal energy expenditure peaks at approximately 50% above adult levels around 1 year of age, then declines to adult baseline levels by age 20, remaining stable through age 60 before declining in older adults.

Your body's energy needs change predictably as you age. You burn significantly more energy relative to your size as a toddler (peaking around age 1) than as an adult. As you age from 20 to 60, your metabolic rate (adjusted for size) stabilizes. After 60, it declines. Do not assume your metabolic rate is constant or scales linearly with your weight; use age- and size-specific estimates for nutritional planning rather than simple weight-based ratios.

Obesity is caused by the interaction of genetic factors with an obesogenic environment (constant access to energy-dense food and minimal physical demands), termed a 'pathoenvironment' or 'obesigenic environment'.

You are living in an environment designed to make you gain weight. This is not your fault alone. Successful weight management requires recognizing this 'pathoenvironment' and actively creating counter-environments (e.g., restricting access to calorie-dense foods, increasing physical demands).

Low-carbohydrate diets do not increase total energy expenditure (TEE) compared to high-carbohydrate diets when analyzed according to pre-registered protocols and accounting for energy conservation laws.

If you are trying to lose weight, switching to a low-carbohydrate diet will not give you a metabolic advantage in terms of burning more calories at rest or during activity compared to a high-carbohydrate diet, provided you eat the same number of calories. Focus on maintaining a caloric deficit rather than macronutrient composition for energy expenditure benefits.

Bariatric surgery is not first-line therapy for women of reproductive age hoping to conceive quickly due to risks of nutrient deficiencies and the required 1-2 year delay before pregnancy.

Avoid bariatric surgery if you plan to get pregnant soon. It requires a 1-2 year wait and can cause vitamin deficiencies that harm the baby. Use weight loss medications instead.

Post-hoc exclusion of participants based on 'Unaccounted Energy' (a post-randomization variable) in feeding studies introduces severe confounding bias, artificially attenuating the observed increase in Total Energy Expenditure (TEE) associated with low-carbohydrate diets.

When evaluating low-carb diet studies, be skeptical of analyses that exclude participants who didn't 'adhere' perfectly. These exclusions often rely on flawed metrics (like Unaccounted Energy) that introduce bias. The original findings of increased energy expenditure on low-carb diets remain robust even when accounting for these methodological errors.

Lean mass is an inaccurate proxy for muscle mass in GLP-1 trials because it includes organs, bone, and fluids; MRI-based muscle volume z-scores provide a more accurate assessment of muscle health.

Do not rely solely on 'lean mass' numbers from standard scales or DXA scans to judge your muscle health. These numbers include water and organ weight. For a true picture of muscle, look at muscle volume and quality via advanced imaging like MRI, which shows if muscle fat is decreasing.

Increased economic development and industrialization are associated with higher obesity rates primarily due to increased caloric intake and diet quality (specifically ultraprocessed foods), rather than reduced physical activity or energy expenditure.

Stop blaming your lack of exercise for your weight gain. This research shows that moving less doesn't necessarily mean you burn significantly less energy than a highly active person of the same size. The real driver of obesity in modern societies is what you eat, specifically the high proportion of ultraprocessed foods that disrupt satiety and increase absorption. Focus on reducing ultraprocessed food intake rather than obsessing over increasing physical activity expenditure to fix obesity.

Intensive lifestyle intervention (ILI) focused on weight loss does not significantly reduce all-cause mortality in older adults with type 2 diabetes and overweight/obesity compared to diabetes support and education (DSE) over a median of 16.7 years.

For older adults with type 2 diabetes, engaging in intensive lifestyle programs (diet and exercise) is recommended to improve quality of life, fitness, and metabolic health, but should not be undertaken with the expectation that it will significantly extend lifespan compared to standard diabetes education. The intervention is safe and does not increase mortality risk.

Obesity is fundamentally a disorder of energy balance where excess energy intake exceeds expenditure, driven by a feedback system derangement involving economic, hedonic, and behavioral overrides rather than simple thermodynamic inefficiency.

Understand that obesity is not just a simple math problem of calories in vs. calories out, but a complex regulatory failure influenced by your environment and biology. To manage weight, you must address the 'hedonic overrides' (taste, convenience, cost) that disrupt your natural energy balance feedback loops, rather than relying solely on willpower.

Creatine supplementation does not significantly affect fat mass (FM), BMI, or body fat percentage (BFP) in the general population, although specific loading protocols with maintenance phases may lead to modest BFP reductions.

Do not take creatine expecting it to burn fat or change your body fat percentage. It will not significantly affect your fat mass or BMI. Its primary benefit is adding lean muscle mass when combined with resistance training.

Intensive lifestyle intervention (caloric restriction and increased physical activity) aiming for ≥7% weight loss in overweight/obese adults with type 2 diabetes does not significantly reduce the rate of major cardiovascular events or mortality compared to diabetes support and education, despite significant improvements in intermediate risk factors.

If you have type 2 diabetes, intensive lifestyle changes to lose 7% of your body weight will significantly improve your blood sugar, blood pressure, and fitness, but it may not be enough on its own to prevent heart attacks or strokes. You should still do it for other health benefits like kidney protection and mobility, but do not assume weight loss replaces the need for cardiovascular medications or monitoring.

Both groups lost similar amounts of lean body mass.

Both dietary approaches may preserve lean body mass during weight loss.

Participants gained 0.8±0.3 kg (p=0.01) during the ultra-processed diet.

Weight gain may occur with the consumption of ultra-processed foods.

Current rates of WMT utilization among patients with obesity are low, increasing from 5.3% to 7.1%.

Efforts should be made to increase the utilization of WMT among patients with obesity.

Gastrointestinal adverse effects were common, but the medication was otherwise well tolerated.

Clinicians should inform patients about potential gastrointestinal side effects while considering the overall tolerability of the treatment.