Browse the evidence

Semaglutide induces body weight loss and metabolic remodeling beyond caloric restriction alone, driven by intake-independent mechanisms including adipose tissue browning, increased sympathetic innervation, and sustained locomotor activity.

Semaglutide provides metabolic benefits that go beyond simply eating less. It promotes fat loss through biological changes like increasing brown fat activity and reducing fat cell size, independent of how much you eat. This suggests that patients may achieve better results with semaglutide than with dieting alone, even if their food intake is similar.

Shifting the Australian population's BMI to an optimal level of ≤25 kg/m² yields substantial health gains, specifically 2.00 million undiscounted Health Adjusted Life Years (HALYs) over 20 years and 20.4 million over the remaining lifetime.

For public health policy, this simulation confirms that population-wide strategies to maintain a BMI under 25 kg/m² are among the most effective interventions for extending healthy life. The benefits are not just individual but systemic, significantly reducing the burden of chronic diseases like heart disease, diabetes, and osteoarthritis, with the greatest relative health improvements occurring in socioeconomically disadvantaged communities.

In oncology patients, muscle-specific strength (MSS) estimated via anthropometry (body weight or calf circumference) or bioimpedance (BIA) provides a reliable alternative to DXA-derived MSS, enabling functional assessment in resource-limited settings.

For cancer patients or clinicians without access to DXA scanners, you can accurately estimate muscle quality by dividing handgrip strength by body weight or calf circumference. This method correlates very strongly with the gold standard DXA test, allowing for effective monitoring of sarcopenia and treatment response in routine clinical settings.

Lean MASLD (normal BMI but with metabolic dysfunction) is a distinct phenotype driven by sarcopenia, adverse fat distribution, and genetic susceptibility, requiring different treatment strategies than obesity-driven MASLD.

If you have a normal BMI but metabolic issues (like high blood sugar or blood pressure), you can still develop fatty liver disease. This 'lean MASLD' is often linked to low muscle mass and genetics. Focus on building muscle and managing metabolic health rather than just losing weight.

Dietary weight loss stabilizes the proportion of lean mass lost (%LML) at approximately 25-33% once total weight loss exceeds 5%, contradicting the hypothesis that lean loss increases proportionally with greater weight loss.

When you lose weight through diet, you will lose some muscle along with fat. This is normal and accounts for about 25-33% of the total weight lost, regardless of how much weight you lose. Men tend to lose a slightly higher percentage of lean mass than women. To minimize this, combine your diet with resistance training and adequate protein intake, but do not fear that larger weight loss equals disproportionately larger muscle loss.

Diet-based weight loss interventions result in minimal loss of appendicular lean soft tissue (a surrogate for skeletal muscle), with losses accounting for less than 10% of total mass loss after adjusting for fat-free adipose tissue.

If you are losing weight through diet alone (without resistance training), you will not lose significant muscle mass. The study found that lean tissue loss was minimal (less than 10% of total weight lost) and that your muscle mass relative to your new body size actually increased. You do not need to fear muscle loss as a barrier to starting a diet.

Protein or amino acid supplementation combined with resistance exercise training in older adults produces a positive but minor effect on whole-body lean mass growth, while having minimal and inconsistent effects on muscle mass, strength, or functional capacity.

If you are an older adult doing resistance training, adding protein or amino acid supplements will likely help you gain a small amount of lean body mass (roughly 0.2-0.8 kg more than exercise alone). However, do not expect significant increases in strength, muscle size, or physical function from the supplement alone; the exercise is doing the heavy lifting. This benefit is most noticeable in frail or sarcopenic individuals, whereas those who are obese may see little to no benefit.

Nutritional interventions (protein, leucine, HMB, creatine) preserve or modestly increase lean mass in sarcopenia but fail to consistently restore muscle strength or physical function when applied in isolation.

Eat enough protein (at least 1.2g per kg of body weight daily) and consider creatine or HMB, but do not expect these supplements to fix your strength or balance on their own. You must combine them with resistance exercise to see functional benefits. Nutrition primes the muscle, but exercise builds the function.

Resistance, sprint, and power training induce a shift from fast-twitch IIx fibers to the fast-twitch IIa phenotype, with minimal change in pure type I fibers.

If you engage in heavy resistance training, expect your muscle fibers to become more efficient at generating power (shifting from IIx to IIa), but do not worry about losing your slow-twitch endurance fibers. This adaptation supports better performance in power activities without compromising your base endurance.

Endurance training induces a shift toward a more oxidative phenotype, characterized by an increase in Type I fibers and a decrease in Type IIa fibers.

High-volume endurance training will make your muscles more efficient at using oxygen by increasing Type I fibers. If you are an endurance athlete, expect this shift. If you are a strength athlete, be aware that excessive endurance work might reduce your peak power, but you can mitigate this with proper tapering.

Consumption of fermented foods is associated with improved gut microbiome diversity, reduced inflammation, and metabolic health benefits, regardless of whether the product contains live microbes or is pasteurized.

Incorporate a variety of fermented foods (yogurt, kefir, sauerkraut, kimchi) into your diet. You do not need to worry if they are pasteurized; both live and dead microbes (postbiotics) offer benefits. If you have high blood pressure, choose lower-sodium options like yogurt or kefir over salty pickles, and consult your doctor if you are immunocompromised or have histamine intolerance.

A multidomain intensive lifestyle intervention (ILI) reduces the incidence of self-reported complaints about decision-making and problem-solving abilities in adults with type 2 diabetes who are overweight but not obese.

If you have Type 2 Diabetes and are overweight (but not obese), committing to a structured lifestyle program involving moderate calorie restriction and regular brisk walking (aiming for 175 minutes a week) can help protect your ability to make decisions and solve problems. This benefit was not seen in obese individuals in this study, so weight management strategies should be tailored carefully.

Modifying the Health Star Rating algorithm to penalize ultra-processed foods (via negative points or score capping) significantly improves alignment with the NOVA classification system, but reduces alignment with current Australian Dietary Guidelines for core food categories like cereals and convenience foods.

Current front-of-pack labels may give a 'health halo' to ultra-processed foods that look nutritious on paper. If you are trying to eat whole foods, look for the NOVA classification or ingredient list complexity, not just the star rating. Be aware that some 'core' foods (like instant oatmeal or plant milks) are ultra-processed and might be penalized by new labeling systems, even if they are currently recommended.

Physical activity attenuates the genetic predisposition to obesity associated with the FTO rs9939609 variant, effectively neutralizing the increased risk of higher BMI and subcutaneous fat area found in carriers of the risk allele.

If you carry the FTO risk gene, you are genetically predisposed to higher BMI, but this risk is not fixed. Regular physical activity and maintaining a healthy energy balance can effectively cancel out this genetic disadvantage. Do not let a genetic test result discourage you; activity is the specific counter-measure for this gene.

Among people with HIV and prediabetes, higher BMI, larger waist circumference, hypertriglyceridemia, and lower CD4 counts are associated with a significantly increased risk of progression to type 2 diabetes.

If you have HIV and prediabetes, your waist size, body weight, and triglyceride levels are strong indicators of your risk of developing full diabetes. Additionally, maintaining a higher CD4 count is protective. You should prioritize lifestyle interventions aimed at weight loss and managing triglycerides, as these are modifiable risk factors that can help prevent progression to diabetes.

Higher BMI categories (Class I-III obesity) are associated with adverse cardiometabolic profiles, including lower HDL-C, higher triglycerides, higher hsCRP, higher prevalence of hypertension and diabetes, lower physical activity (step counts), and higher mental health distress (PHQ-9/GAD-7 scores) compared to normal weight.

Maintaining a healthy weight is crucial for reducing cardiometabolic risk, but it is not the only factor. Individuals, especially those who are underweight or have obesity, should monitor blood pressure, lipids, inflammation (hsCRP), and mental health. Regular physical activity and managing stress are key components of overall health regardless of BMI category.

For middle-aged and elderly adults with type 2 diabetes, maintaining a longitudinal BMI within 18.5–26.9 kg/m² significantly reduces all-cause, cardiovascular, and cancer mortality compared to lower or higher sustained BMI levels.

If you have type 2 diabetes, aim to keep your BMI between 18.5 and 26.9 kg/m² over the long term. This range is associated with the lowest risk of death from all causes, heart disease, and cancer. Avoid sustained periods where your BMI is consistently above 27 kg/m², as this increases mortality risk.

Sustained exposure to a BMI of 27 kg/m² or higher is positively associated with increased all-cause, cardiovascular, and cancer mortality in patients with type 2 diabetes.

Keep your BMI below 27 kg/m². Sustained exposure to a BMI of 27 or higher increases your risk of dying from heart disease, cancer, or other causes. If your BMI is consistently above 27, work with your doctor to lower it gradually.

Obesity accelerates aging and increases mortality risk in younger individuals, but the relationship between adiposity and mortality becomes non-linear and potentially protective in elderly populations, where overweight status may be associated with lower mortality than healthy weight.

If you are older, do not panic about being slightly overweight (BMI 25-30). Research suggests this range may be associated with better survival outcomes than being underweight or even 'healthy' weight in the elderly. Focus on maintaining muscle mass and metabolic health rather than aggressive weight loss, which can be detrimental in older adults.

Among individuals with overweight or obesity who achieve initial weight loss (≥5%) in the first year, long-term maintenance of that weight loss (years 6-15) is significantly greater for those assigned to metformin compared to those assigned to intensive lifestyle intervention (ILS).

If you have prediabetes or are at high risk, achieving even a modest 5% weight loss in the first year is a strong predictor of long-term success. For those who achieve this, adding metformin (if prescribed) may help you keep the weight off better than lifestyle changes alone over the long haul (10+ years). It acts as a maintenance aid rather than just an initial weight loss tool.

Fatmax training does not significantly increase maximal oxygen consumption (VO2max) compared to other forms of exercise, but it does improve it in sedentary obese individuals.

Fatmax training improves cardiovascular fitness (VO2max) in obese, sedentary individuals, though the gains are modest. It is a safe starting point for those who cannot tolerate high-intensity exercise.

Intermittent fasting (IF) significantly reduces body weight, BMI, body fat mass, LDL cholesterol, and triglycerides in Chinese adults compared to control groups, but does not significantly reduce waist circumference, total cholesterol, HDL cholesterol, fasting glucose, or blood pressure.

If you are Chinese and looking to lose weight or improve lipid profiles, intermittent fasting (like 16:8 TRE or 5:2) is an effective strategy. Expect a modest weight loss (around 2kg) and improvements in LDL and triglycerides. However, do not expect IF to significantly lower your blood pressure or fasting glucose on its own. Adherence may be challenging due to typical eating patterns, so choose a protocol that fits your lifestyle.

Alternate-day modified fasting (ADMF) improves subjective sleep quality (SSQ) and reduces daytime dysfunction compared to daily calorie restriction, but does not significantly change total sleep quality (PSQI) or daytime sleepiness (ESS).

If you are an overweight woman, ADMF may help you feel more rested during the day and improve your subjective sense of sleep quality, even if it doesn't change your total sleep score or daytime sleepiness levels. Focus on the daytime benefits rather than just sleep duration.

Dietary composition directly and rapidly alters gut microbiome composition, with plant-based diets increasing beneficial SCFA-producing bacteria (Bifidobacteria, Lactobacilli) and animal-based/high-fat diets increasing bile-tolerant anaerobes (Bacteroides, Bilophila) and pro-inflammatory pathways.

Focus on the type of food rather than just calories. Plant-based proteins (pea, whey) and fibers increase beneficial bacteria that produce anti-inflammatory short-chain fatty acids. Animal proteins and high saturated fats tend to increase bile-tolerant bacteria linked to inflammation. Prioritize whole food sources of carbohydrates (fiber) over artificial sweeteners to support a healthy microbiome.