Browse the evidence

Abdominal or upper-body obesity is independently associated with a higher risk of developing type 2 diabetes, hypertension, and cardiovascular disease compared to lower-body fat distribution.

If you are overweight, where you carry the weight matters for your health risks. Abdominal or upper-body fat is more strongly linked to diabetes and heart disease than lower-body fat. Monitoring waist circumference may provide better insight into your metabolic risk than BMI alone.

Obesity is associated with an increased risk of hypertension, with risk increasing as BMI and abdominal obesity increase.

Managing your weight is important for preventing high blood pressure. The risk of developing hypertension increases as your BMI increases, and those with a BMI of 32 or higher have nearly five times the risk compared to those with a BMI of 23 or lower.

Obesity is associated with an increased risk of coronary heart disease (CHD) mortality, with risk increasing as BMI and waist-to-hip ratio increase.

Maintaining a healthy weight is crucial for preventing heart disease. The risk of dying from coronary heart disease increases significantly as your BMI rises, with those having a BMI of 32 or higher facing nearly six times the risk compared to those with a BMI under 22.

Obesity is associated with an increased risk of gallbladder disease, with risk increasing as BMI and waist-to-hip ratio increase.

Maintaining a healthy weight can help prevent gallbladder disease. The risk of being hospitalized for gallbladder disease increases as your BMI increases, with morbidly obese women facing 2.5 times the risk compared to those with a BMI under 25.

Obesity is associated with an increased risk of cancer mortality, with risk increasing as BMI increases.

Maintaining a healthy weight can help reduce the risk of dying from cancer. The risk of cancer mortality increases as your BMI increases, with women who are at least 40% overweight facing 55% higher risk compared to those of average weight.

Obesity is associated with an increased risk of all-cause mortality, with risk increasing as BMI increases.

Maintaining a healthy weight is crucial for longevity. The risk of dying from any cause increases as your BMI rises, with the lowest mortality found among those with a BMI between 19.0 and 26.9 kg/m2.

Age-related sarcopenia is driven by a combination of motor unit loss, fiber atrophy (specifically Type II), inflammatory cytokine expression, and hormonal declines (IGF-1, testosterone).

Understanding that muscle loss is biological (hormonal/inflammatory) helps explain why it happens, but it does not negate the effectiveness of exercise as a treatment.

In healthy men, estrogen deficiency (caused by aromatase inhibition) is the primary driver of increased body fat, whereas testosterone deficiency is the primary driver of decreased lean mass, muscle size, and strength.

If you are a man experiencing fat gain or loss of muscle/strength, do not assume it is solely due to low testosterone. This study shows that low estrogen (estradiol) is a primary driver of fat gain, while low testosterone drives muscle loss. Treatment strategies should consider both hormones, not just testosterone replacement.

Sexual desire and erectile function decline when both testosterone and estradiol levels are low, indicating that both hormones are required for normal sexual function.

If you are experiencing low libido or erectile dysfunction, check both your testosterone and estradiol levels. Low estrogen can impair sexual function even if testosterone is normal. A balanced hormonal profile is key for sexual health.

Type 2 diabetes mellitus (T2DM) and insulin resistance are significant independent risk factors for the progression of NAFLD to NASH, fibrosis, and cirrhosis, and are associated with increased mortality.

If you have NAFLD and Type 2 Diabetes, managing your blood sugar and insulin resistance is critical to preventing liver damage. T2DM is an independent risk factor for progression to cirrhosis and liver-related mortality.

GLP-1 receptor agonists (GLP-1RAs) effectively treat type 2 diabetes and obesity by mimicking endogenous GLP-1 to stimulate glucose-dependent insulin secretion, suppress glucagon, delay gastric emptying, and reduce appetite via central nervous system signaling.

GLP-1 medications are highly effective for managing type 2 diabetes and obesity. They work by mimicking a natural hormone to boost insulin when needed, lower blood sugar, slow digestion, and reduce hunger. While they often require injections, many are now available as once-weekly shots or even pills. Side effects like nausea are common at first but usually fade. They are not for type 1 diabetes. Always combine with diet and exercise.

Pharmacological therapy with statins, fibrates, niacin, or thiazolidinediones (TZDs) can improve the atherogenic dyslipidemic phenotype in type 2 diabetes, leading to reduced coronary artery disease progression and cardiovascular events.

While diet and exercise are crucial, most people with type 2 diabetes and abnormal lipids will likely need medication to protect their heart. Drugs like statins, fibrates, or TZDs can significantly lower your risk of heart attacks and stroke by correcting specific blood fat abnormalities that lifestyle changes alone might not fully fix. Discuss these options with your doctor.

Weight gain during adulthood (after age 18) is a stronger predictor of diabetes risk than being overweight at age 18, as the risk associated with early-life BMI is eliminated when adjusted for current BMI.

Your weight at age 18 does not permanently sentence you to diabetes. What matters most is your current weight and how much weight you have gained since young adulthood. If you were heavier in your youth but have since reached an average or healthy weight, your risk is significantly lower than if you had remained heavy. Focus on preventing weight gain in adulthood.

Central (visceral) obesity is a primary driver of metabolic syndrome, hypertension, and insulin resistance through mechanisms involving increased lipolysis, pro-inflammatory cytokine release, and free fatty acid flux to the liver.

Focus on reducing abdominal fat, as it is more dangerous than fat stored elsewhere. This involves managing overall energy balance and addressing insulin resistance through lifestyle changes, as visceral fat drives metabolic syndrome.

Women with polycystic ovary syndrome (PCOS) exhibit intrinsic insulin resistance independent of body mass index (BMI), with a prevalence of 75% in lean women and 95% in overweight women, as measured by the gold-standard euglycaemic-hyperinsulinaemic clamp.

If you have PCOS, do not assume your metabolic health is determined solely by your weight. Even if you are lean, you may have 'intrinsic' insulin resistance that lifestyle changes alone cannot fully correct. This biological reality requires targeted medical screening (like glucose tolerance tests) and potentially pharmacological interventions (like metformin) alongside lifestyle changes, regardless of your BMI.

Obesity (excess body fatness) is a convincing risk factor for at least 13 different cancer sites, including endometrial, postmenopausal breast, colorectal, esophageal, renal, meningioma, pancreatic, gastric cardia, liver, multiple myeloma, ovarian, gallbladder, and thyroid cancers.

Maintain a healthy body weight to reduce cancer risk. Focus on sustainable lifestyle changes like balanced nutrition and regular activity rather than rapid weight loss, as avoiding weight gain is a viable preventive measure.

In postmenopausal women, higher baseline BMI (specifically ≥35.0) is associated with a significantly increased risk of invasive breast cancer, particularly estrogen receptor-positive subtypes, and is linked to more advanced disease characteristics and higher mortality.

For postmenopausal women, maintaining a healthy weight (BMI < 25) is critical for reducing invasive breast cancer risk, especially estrogen receptor-positive types. While weight loss after becoming obese may not reverse the elevated risk established by high BMI, preventing obesity in the first place is the most effective strategy. Regular screening is essential, as obesity is also linked to more advanced disease stages.

Visceral fat is more metabolically hazardous than subcutaneous fat because it is more sensitive to lipolytic stimuli and releases free fatty acids directly into the portal vein, leading to hepatic insulin resistance and ectopic fat storage.

Target visceral fat reduction through diet and exercise. This type of fat is more dangerous than subcutaneous fat because it directly impacts liver health and insulin sensitivity.

FGF21 is required for the metabolic and behavioral adaptations to protein restriction, including increased energy expenditure, increased food intake, and reduced body weight gain.

This mechanism is specific to rodents; humans do not have FGF21 knockout models. However, it suggests that FGF21 signaling is a critical link between protein intake and metabolic rate. Low protein intake may blunt metabolic adaptation if FGF21 signaling is impaired.

Glucose tolerance decreases significantly from morning to evening, resulting in higher postprandial blood glucose levels in the afternoon and evening compared to the morning, driven by reduced insulin sensitivity and secretion.

Your body handles carbohydrates better in the morning. If you eat the same meal in the evening, your blood sugar will spike significantly higher (by 30-50 mg/dl) than if you ate it in the morning, even if you fasted for the same amount of time. Prioritize higher-carb meals earlier in the day to minimize glucose spikes.

Circadian rhythmicity and sleep independently and additively decrease glucose tolerance, with the combined effect of nighttime sleep and circadian timing causing the lowest glucose tolerance of the 24-hour cycle.

Your body's ability to regulate blood sugar drops significantly during sleep, even if you aren't eating. This is due to both the time of day (circadian rhythm) and the act of sleeping itself. Prioritizing good sleep hygiene helps maintain stable glucose levels overnight.

Higher levels of even-chain saturated fatty acids (myristic, palmitic, and stearic acid) in plasma phospholipids are positively associated with an increased risk of incident type 2 diabetes, whereas higher levels of odd-chain (pentadecanoic, heptadecanoic) and long-chain (arachidic, behenic, tricosanoic, lignoceric) saturated fatty acids are inversely associated with type 2 diabetes risk.

Stop treating all saturated fats as the same enemy. The type of fat matters significantly for diabetes risk. High levels of even-chain fats (like palmitic and stearic acid, often linked to processed foods and animal fats) are associated with higher diabetes risk. Conversely, odd-chain fats (like pentadecanoic and heptadecanoic acid, biomarkers for dairy fat) and long-chain fats are associated with lower risk. Focus on the quality and source of your fats rather than just minimizing total saturated fat intake.

Smoking (active and passive) significantly reduces fertility in both men and women, delaying conception and reducing ART success rates, with mechanisms including DNA damage, altered hormone levels, and zona pellucida thickening.

Stop smoking immediately if you are trying to conceive. This applies to both partners. Smoking reduces sperm quality in men and egg quality/hormonal balance in women. It also reduces the success of IVF. Quitting improves your chances of natural conception and ART success.

Subcutaneous white adipose tissue (WAT) expansion is metabolically protective, whereas preferential visceral WAT expansion is associated with increased risk for insulin resistance and metabolic syndrome.

Monitor your waist circumference as a proxy for visceral fat. A high waist-to-hip ratio indicates visceral fat accumulation, which is a stronger risk factor for diabetes and heart disease than overall BMI. Prioritize strategies that favor subcutaneous fat storage or prevent visceral accumulation, such as regular aerobic exercise and stress management.