Browse the evidence

Long-term DHEA replacement (50 mg/day) in patients with primary adrenal insufficiency reverses bone mineral density loss at the femoral neck and increases total and truncal lean mass without changing fat mass.

If you have Addison's disease, your body doesn't make enough DHEA. Taking 50mg of DHEA daily for a year can help stop bone loss in your hip and build muscle mass without adding fat. This is a specific medical treatment for a specific deficiency, not a general supplement for healthy people.

Aerobic exercise training (AEX) improves insulin-mediated glucose disposal (tissue sensitivity) in obese sedentary older men, but does not improve oral glucose tolerance (OGTT) unless combined with weight loss.

For older obese men, doing 40 minutes of moderate-to-vigorous aerobic exercise three times a week significantly improves how your body uses insulin, even if your weight doesn't change. However, to improve your body's response to a sugar load (oral glucose tolerance), you likely need to combine this exercise with actual weight loss.

Increased body weight and mechanical loading via the mechanostat increase bone mass and reduce osteoporosis prevalence, but this benefit plateaus or reverses at morbid obesity levels due to compromised bone quality and altered fracture mechanics.

Maintaining a healthy body weight is crucial for bone health because mechanical loading stimulates bone formation. However, extreme obesity may not provide additional bone benefits and can compromise bone quality. Focus on preserving lean muscle mass and engaging in weight-bearing activities rather than simply pursuing weight loss if your bone density is low.

Sarcopenic obesity (low muscle mass combined with high visceral adiposity) is significantly associated with increased physical functioning problems in older adults, and this association is partially mediated by insulin resistance.

For older adults, maintaining muscle mass is not enough if visceral fat is high. The combination of low muscle and high belly fat creates a metabolic state (insulin resistance) that actively harms physical function. To preserve mobility, interventions must address both muscle preservation and metabolic health (reducing visceral fat/insulin resistance), not just one or the other.

Muscle disuse induces muscle-specific insulin resistance (IR), which accelerates muscle mass loss, particularly in individuals with pre-existing Type 2 Diabetes.

If you have Type 2 Diabetes or insulin resistance, your muscles are more vulnerable to loss during periods of inactivity. Disuse makes your muscles resistant to insulin, which accelerates muscle breakdown. Managing blood sugar and attempting any safe movement or protein intake can help mitigate this accelerated loss.

Short-term withdrawal (2-4 days) from caffeine restores the plasma norepinephrine response to acute caffeine ingestion during exercise, which is blunted in habitual users without withdrawal.

For habitual caffeine users, stopping caffeine for 2-4 days before an event will trigger a stronger norepinephrine spike when you take caffeine, compared to taking it while still consuming your normal amount. However, this hormonal spike does not appear to improve performance (endurance) compared to taking caffeine without withdrawal.

High-fat diets increase circulating lipopolysaccharide (LPS) levels ('metabolic endotoxemia'), which triggers systemic inflammation and insulin resistance via the TLR4 pathway.

High-fat meals can increase gut-derived toxins (LPS) in the blood, triggering inflammation that worsens insulin resistance. Reducing dietary fat, particularly saturated fats, may help lower this inflammatory burden.

Androgen deprivation therapy (ADT) for prostate cancer causes significant metabolic complications, including insulin resistance, hyperglycemia, and metabolic syndrome, which accelerate cardiovascular mortality.

If you are undergoing Androgen Deprivation Therapy for prostate cancer, you are at a significantly higher risk for developing diabetes, high cholesterol, and heart disease. You must undergo regular screening for blood sugar and lipids. Aggressively manage your weight, diet, and exercise to counteract the muscle loss and fat gain caused by the therapy. Discuss cardiovascular risk with your doctor before starting treatment.

Hormonal Replacement Therapy (HRT) reduces visceral fat mass and improves insulin sensitivity in postmenopausal women, particularly when initiated during perimenopause or early menopause.

If you are going through menopause and concerned about weight gain, talk to your doctor about Hormonal Replacement Therapy (HRT). Starting HRT early (during perimenopause or shortly after menopause) can help reduce belly fat and improve how your body handles sugar. However, this should be combined with a healthy diet and exercise, and only done if your doctor determines it is safe for you.

Growth hormone (GH) administration during caloric restriction preserves lean body mass (nitrogen retention) for approximately 5 weeks, after which the anabolic effect is lost despite continued GH treatment.

If you are using Growth Hormone to preserve muscle while dieting, expect it to work for about 5 weeks. After that, the muscle-saving benefit disappears even if you keep taking it. It does not accelerate fat loss, so the risk/cost ratio worsens over time. Do not rely on it for long-term body composition changes.

Vigorous late-night exercise (ending ~2 hours before bedtime) does not disturb polysomnographic, actigraphic, or subjective sleep quality in healthy, physically fit young adults, despite causing elevated heart rate during the first three hours of sleep.

If you are young and physically fit, doing a hard workout late at night (ending about 2 hours before bed) will not ruin your sleep. You might wake up with a higher heart rate initially, but you will still fall asleep easily and get good restorative sleep. You do not need to stop exercising late just because of sleep concerns.

High-fat diets rich in saturated fatty acids (SFA) and Conjugated Linoleic Acids (CLA) induce hepatic steatosis, whereas diets rich in n-3 polyunsaturated fatty acids (PUFA) inhibit hepatic lipogenesis and prevent steatosis.

The type of fat you eat matters more than just the amount. Diets high in saturated fats and CLA can cause fatty liver, while diets rich in n-3 PUFAs (found in fish and some plant oils) can prevent it. Focus on the quality of your fats.

Women with polycystic ovary syndrome (PCOS) exhibit a distinct dyslipidemic profile characterized by elevated triglycerides, elevated LDL cholesterol, and reduced HDL cholesterol compared to controls, independent of obesity status.

If you have PCOS, you need a complete lipid panel (including ApoA-I and Lipoprotein(a)) regardless of your weight. Lifestyle changes (diet/exercise) are the first-line treatment, but you may require statins if LDL remains high, as your hormonal profile drives atherogenic changes independent of body mass.

Obstructive sleep apnea (OSA) independently causes insulin resistance, hypertension, and visceral obesity, contributing directly to the metabolic syndrome.

If you have symptoms of sleep apnea (loud snoring, daytime fatigue, witnessed breathing pauses), get tested. Treating OSA with CPAP can improve blood pressure, lipid profiles, and insulin sensitivity, reducing your risk of heart disease and diabetes, independent of weight loss.

Sleep deprivation and short sleep duration independently increase the risk of insulin resistance, glucose intolerance, and obesity.

Aim for 7-9 hours of sleep per night. Chronic sleep restriction (<6 hours) impairs your body's ability to process glucose and increases hunger hormones, making weight management and diabetes prevention significantly harder.

Aerobic exercise training increases skeletal muscle GLUT4 protein levels, which enhances insulin-stimulated muscle glucose disposal.

Regular aerobic exercise increases the amount of GLUT4, a protein that helps move glucose into your muscles. This makes your body more sensitive to insulin and helps manage blood sugar levels more effectively.

In Chinese adults with type 2 diabetes, higher levels of abdominal obesity indices (waist circumference, visceral adiposity index, lipid accumulation product, and Chinese visceral adiposity index) are significantly associated with an increased risk of incident cardiovascular events, with CVAI demonstrating the strongest predictive performance.

For people with type 2 diabetes, monitoring waist circumference or using calculated indices like CVAI is more critical for predicting heart disease risk than BMI alone. Reducing abdominal fat deposition is a key intervention strategy, particularly for those who are not overweight by BMI standards but carry visceral fat.

Sustained high-wheat fibre intake (24 g/d) increases plasma glucagon-like peptide-1 (GLP-1) and short-chain fatty acids (SCFA) in hyperinsulinaemic subjects, but this adaptation requires 9–12 months to manifest.

If you are insulin resistant, simply adding 24g of wheat fibre daily (e.g., one serving of high-fibre cereal) will not immediately fix your blood sugar. It takes 9 to 12 months of consistent intake for your gut bacteria to adapt and produce enough SCFA to boost GLP-1, a hormone that helps regulate insulin. Do not quit after a few months; the benefit is delayed but real.

Ectopic fat accumulation in organs such as the heart, liver, and pancreas is a primary driver of cardiometabolic disease and insulin resistance, often posing a higher risk than classical metrics like BMI.

Focus on reducing visceral and ectopic fat through lifestyle changes rather than just tracking weight. Regular exercise and a balanced diet are effective at reducing hepatic and pancreatic fat, which improves metabolic health even if BMI changes slowly.

GLP-1 receptor agonists (Exenatide and Liraglutide) are marketed drugs that suppress appetite and reduce body weight while improving glycemic control in diabetic patients.

If you have Type 2 Diabetes, ask your doctor about GLP-1 receptor agonists like Exenatide or Liraglutide. These are already available medications that help control blood sugar and also help with weight loss by suppressing appetite.

Low energy availability (LEA), defined as ≤30 kcal/kg LBM/day, acts as a potent disruptor of the endocrine milieu, triggering acute hormonal, metabolic, and physiological dysregulations in both females and males.

To maintain hormonal health, ensure your daily energy intake minus exercise expenditure, divided by your lean body mass, stays above 30 kcal/kg. This is critical for both men and women exercising regularly.

Twelve weeks of progressive aerobic exercise training increases markers of mitochondrial biogenesis (PGC-1α, CS, βHAD, SDH, COXIV) and dynamics (MFN1, MFN2, FIS1) in older men (74 ± 3 y) to a similar extent as in young men (20 ± 1 y).

If you are a healthy older man, engaging in 12 weeks of progressive aerobic exercise (like cycling) 3-4 times a week at 60-80% of your heart rate reserve will significantly boost your mitochondrial health and muscle size. Your body's ability to adapt to this exercise is comparable to that of a young adult, meaning you can achieve substantial improvements in aerobic capacity and muscle quality regardless of your age.

Anti-Müllerian Hormone (AMH) testing can be used as an alternative to ultrasound for diagnosing PCOS in adults, offering a low-cost, convenient option without evidence of overdiagnosis.

If you are an adult being evaluated for PCOS, ask your doctor if Anti-Müllerian Hormone (AMH) blood testing is a suitable alternative to ultrasound. This may be a more convenient and cost-effective diagnostic option with strong supporting evidence.

High-frequency low-dose caffeine administration (0.3 mg/kg/hour) effectively counteracts cognitive performance degradation and prevents accidental sleep onsets during extended wakefulness, particularly during the circadian performance nadir.

If you are facing a long shift or extended wakefulness, take small doses of caffeine (approx 0.3 mg per kg of body weight) every hour rather than one large dose. This strategy keeps your cognitive performance sharp and prevents accidental sleep, especially during your body's natural low-energy window (circadian nadir). Be aware that you might feel more subjectively sleepy than usual, but your objective performance will be protected.