Browse the evidence

Higher consumption of fish is negatively associated with the risk of dementia, with each serving per day associated with a significant reduction in risk.

Incorporate fish into your diet regularly. This study found that each daily serving of fish was associated with a nearly 69% reduction in the odds of dementia. Aim to include fish as a regular part of your meals to support cognitive health.

Higher consumption of non-refined cereals is positively associated with better composite cognitive performance.

Choose non-refined cereals over refined ones. This study found that higher consumption of non-refined cereals was linked to better overall cognitive performance. Swapping refined grains for whole grains may support cognitive health.

Testosterone supplementation increases fat-free mass and maximal voluntary strength in hypogonadal men, regardless of whether the dose is physiologic or supraphysiologic.

If you are a man with clinically low testosterone, testosterone replacement therapy will reliably increase your muscle mass and strength. This holds true whether you are older, HIV-positive, or even if you have normal testosterone levels but take high doses. However, do not expect this to improve your endurance running or cycling performance, nor does it guarantee a reduction in falls for older adults. Consult a doctor for blood tests before considering treatment.

High body fat percentage (BFP) and high visceral adipose index (VAI) are significantly associated with increased risk of overweight/obesity and abdominal obesity, whereas smoking and alcohol consumption are not associated with these conditions in southern China.

Focus on body composition rather than just weight. If you have a normal BMI but a high waist circumference or body fat percentage, your risk for metabolic issues is still elevated. Regularly monitoring waist circumference and body fat percentage is more informative than BMI alone for assessing obesity-related risks.

Long-term calcium (1,000 mg) and vitamin D3 (400 IU) supplementation reduces hip fracture risk in postmenopausal women who do not take personal supplements at baseline, with a hazard ratio of 0.62 after 5+ years.

If you are a postmenopausal woman and you do not currently take calcium or vitamin D supplements, taking 1,000 mg of calcium carbonate and 400 IU of vitamin D3 daily for at least 5 years can significantly reduce your risk of hip fractures. If you already take these supplements, adding more from this specific trial protocol does not appear to provide additional fracture protection. Be aware that this regimen slightly increases the risk of kidney stones, but does not increase cardiovascular risk.

Calcium and vitamin D supplementation (1,000 mg/400 IU) does not increase the risk of cardiovascular events (MI, stroke, CHD) in postmenopausal women, contradicting claims of adverse cardiovascular effects.

You do not need to avoid calcium and vitamin D supplements due to fear of heart attacks. This study of over 36,000 women found no increase in heart attacks, strokes, or other cardiovascular diseases with 1,000 mg calcium and 400 IU vitamin D3 daily. The primary benefit is bone health, specifically for those who do not already take these supplements.

Calcium and vitamin D supplementation (1,000 mg/400 IU) is associated with a modest reduction in urinary tract stone risk in adherent users, though the overall risk increase is small (HR 1.17).

Taking 1,000 mg of calcium and 400 IU of vitamin D3 daily slightly increases your risk of developing kidney stones (from 0.30% to 0.35% over 7 years). If you are prone to stones, discuss this with your doctor. However, for most women, this small risk is balanced by the significant benefit of reduced hip fracture risk.

Higher consumption of an unhealthy 'Western' dietary pattern is independently associated with smaller left hippocampal volume in older adults, while higher consumption of a healthy 'prudent' dietary pattern is associated with larger left hippocampal volume.

Focus on eating a 'prudent' diet rich in vegetables, fruit, whole grains, and fish, while minimizing 'Western' foods like processed meats, fried foods, and sugary drinks. This dietary pattern is associated with larger hippocampal volume, a brain region critical for memory and mood, in older adults.

Short-acting GLP-1 receptor agonists (exenatide twice daily, lixisenatide) produce greater reductions in postprandial glucose than long-acting agents (liraglutide, dulaglutide, exenatide once weekly) due to delayed gastric emptying, whereas long-acting agents provide superior fasting glucose control.

If you struggle with blood sugar spikes after meals, short-acting GLP-1 drugs (taken twice daily or before meals) may work better for you. If your main issue is high fasting blood sugar in the morning, long-acting GLP-1 drugs (taken once daily or weekly) are likely more effective. Discuss these options with your doctor to match the drug's mechanism to your specific glucose pattern.

Substituting red meat with white meat, particularly unprocessed white meat, is associated with a 25% reduction in all-cause mortality.

Try swapping your red meat meals for white meat, like chicken or fish. This study shows that making this swap, while keeping your total meat amount the same, can significantly lower your risk of dying from common diseases.

Replacing saturated and trans fatty acids with unsaturated fatty acids lowers LDL cholesterol and reduces cardiovascular disease risk, whereas simply reducing total fat without this substitution may worsen the lipid triad (high triglycerides, low HDL, small LDL particles).

Focus on swapping saturated fats (like butter or fatty meats) for unsaturated fats (like olive oil, nuts, or fish) rather than just cutting total fat. Simply eating less fat but replacing it with refined carbohydrates may not improve your cholesterol profile and could worsen it.

Reducing total fat intake in children and adolescents to 28-34% of energy does not compromise growth or development, provided total energy and essential nutrient intakes are adequate.

For children over 2, you can safely reduce fat to about 30% of calories without worrying about stunted growth, as long as they are eating enough total food and getting enough protein. Do not restrict fat in infants under 2.

In male patients, abdominal (waist) circumference is a closer independent correlate of OSA severity (AHI) than neck circumference or BMI, whereas in female patients, neck circumference is the best anthropometric correlate.

Body shape matters for OSA risk assessment differently for men and women. For men, waist size is a better indicator of OSA severity than neck size. For women, neck size remains the key anthropometric indicator. Doctors should account for these sex-specific differences when assessing risk.

Substituting dietary saturated fatty acids with monounsaturated or polyunsaturated fatty acids improves insulin sensitivity in healthy individuals, whereas high saturated fat intake is associated with insulin resistance.

To improve your body's sensitivity to insulin, focus on the quality of the fats you eat rather than just cutting total fat. Replace saturated fats (found in red meat, butter) with unsaturated fats (found in olive oil, nuts, seeds, fish). This substitution, done while keeping your overall calorie intake stable, has been shown to improve insulin sensitivity. You do not need to eliminate fat entirely; simply choosing the right types supports metabolic health.

Both exercise alone and combined exercise/diet interventions significantly improve knee pain, disability, and physical performance in older adults with knee osteoarthritis, with no significant between-group differences in pain scores.

Starting an exercise program is beneficial for reducing knee pain and improving function in older adults with osteoarthritis, regardless of whether they lose weight. You do not need to lose weight to get pain relief from exercise, although losing weight may offer additional biomechanical benefits.

Calorie restriction (CR) without malnutrition prevents or delays age-associated chronic diseases, including abdominal obesity, type 2 diabetes, hypertension, and cardiovascular diseases, in both non-human primates and humans.

To gain the anti-aging benefits of calorie restriction, reduce your daily calorie intake by 30-60% compared to your current maintenance level, but ensure you are eating nutrient-dense foods that provide 100% of your daily requirements for vitamins, minerals, and protein. This approach has been shown to protect against obesity, diabetes, and heart disease in both monkeys and humans.

Higher proportions of saturated fatty acids (palmitic acid) and lower proportions of linoleic acid in serum lipids and skeletal muscle phospholipids are strongly associated with reduced insulin sensitivity in observational studies.

Your blood fat profile (specifically high saturated fat and low linoleic acid) is a strong warning sign for insulin resistance. While changing fats won't 'cure' resistance quickly, maintaining a profile rich in unsaturated fats is associated with better insulin sensitivity.

Metformin treatment in women with PCOS leads to regularization of the menstrual cycle, reduction in hyperandrogenism, and improvement in cardiovascular risk factors.

If you have PCOS, ask your doctor about metformin. It is the most common medication used for this condition because it helps fix the underlying insulin resistance. This can help restore regular periods, lower male hormone levels, and improve heart health risks. Lifestyle changes like diet and exercise are also recommended, especially if you are overweight.

High intake of high fructose corn syrup (HFCS) from processed foods and beverages promotes de novo lipogenesis, insulin resistance, and liver fibrosis, whereas fructose from whole fruits does not carry the same risk and is safe within a Mediterranean diet.

Avoid sugary drinks and processed foods containing high fructose corn syrup, as they directly contribute to liver fat and fibrosis. You do not need to avoid whole fruits, which are part of a healthy Mediterranean diet. Focus on reducing added sugars to improve liver health.

Long-term administration of nutritional interventions that accelerate recovery from exercise-induced muscle damage (EIMD) may impinge on muscle adaptation due to the hormetic effect of blunting necessary inflammatory signaling.

Do not use recovery supplements (like high-dose antioxidants or anti-inflammatories) every day. Reserve them for specific high-stress periods, such as tournament weeks or when you have back-to-back competitions. On normal training days, allow natural inflammation to occur to ensure your muscles adapt and grow.

Acute intranasal insulin administration reduces food intake in men but not in women, indicating higher sensitivity of men to central anorexigenic insulin signaling.

If you are a healthy man, acute intranasal insulin may help you eat less, but this effect does not appear to exist for women. This suggests that treatments targeting central insulin signaling for weight loss may need to account for gender-specific biological responses.

Increasing the price of specific foods like edible vegetable oil and pork can effectively reduce fat intake in the population, particularly among the poor.

Policymakers can use food pricing strategies to reduce fat intake. Increasing the price of edible oils and pork can lower fat consumption without harming protein intake for low-income groups.

Calcium supplementation combined with Vitamin D reduces hip fracture incidence in elderly women (mean age 84) and non-vertebral fracture rates in older adults (mean age 71).

If you are elderly, taking both Calcium and Vitamin D together is more effective for preventing hip fractures than Calcium alone. This combination helps correct Vitamin D status and lowers PTH, which protects bone.

High fitness levels attenuate mortality risk in obese individuals, making it more beneficial to be fit and overweight than normal weight and unfit.

Do not let your weight stop you from exercising. Improving your fitness (cardiovascular capacity) significantly lowers your mortality risk, even if you are obese. It is better to be a fit overweight person than an unfit normal-weight person. Focus on building fitness through regular activity.