Browse the evidence

Dual-Energy X-ray Absorptiometry (DXA) is a precise, safe, and widely available method for assessing body composition, specifically Lean Soft Tissue (LST) and Appendicular Skeletal Muscle (ASM), though it has limitations regarding body thickness and hardware variability.

If you need an accurate assessment of your muscle mass (specifically in arms and legs) and body fat, DXA is the preferred clinical tool due to its high precision and safety. It is increasingly available as a 'secondary' use of osteoporosis scanners. Ensure the machine is properly calibrated, as results can vary between manufacturers.

Cancer survivors, particularly men with prostate cancer and African American patients, consume significantly fewer than the recommended 5 daily servings of fruits and vegetables, indicating a need for targeted nutritional interventions.

Most cancer survivors do not eat the recommended 5 daily servings of fruits and vegetables. Men and African American patients are particularly likely to fall short of this goal. To improve health outcomes, consider using mailed educational resources or working with a dietitian to gradually increase fruit and vegetable intake, as this is a common area for improvement among survivors.

Dietary restriction (DR), particularly caloric restriction, is the most robust non-genetic intervention shown to extend lifespan across multiple species, from yeast to mammals.

While the paper does not provide a human protocol, it establishes that caloric restriction is the most robust non-genetic method for extending lifespan in biological models. For humans, this translates to exploring nutrient-dense, energy-restricted diets under medical supervision, with the goal of mimicking the genetic and metabolic benefits observed in model organisms, such as those identified in the GenDR database.

Men who spend more than 10 hours per week riding in a car or more than 23 hours per week in combined sedentary behaviors (car riding plus TV viewing) have a significantly higher risk of cardiovascular disease mortality compared to those with lower sedentary time, even after adjusting for physical activity levels.

If you spend more than 10 hours a week driving or over 23 hours a week on sedentary activities like driving and watching TV, your risk of dying from heart disease is significantly higher, even if you exercise. To protect your heart, try to break up long periods of sitting and reduce total sedentary time in addition to staying active.

High levels of physical activity are associated with notably lower rates of cardiovascular disease mortality even in the presence of high levels of sedentary behavior, suggesting that physical activity mitigates but does not entirely eliminate the risk associated with sedentary time.

Being physically active significantly lowers your risk of heart disease death, even if you sit for long periods. However, to get the best protection, you should also try to reduce your total sedentary time. Don't rely on exercise alone to offset the risks of a sedentary lifestyle.

Whole-of-dietary interventions significantly reduce symptoms of depression compared to control conditions, with a small-to-moderate effect size (Hedges' g = 0.275).

Improving your overall diet quality, whether by focusing on nutrients, reducing fat, or managing weight, can help reduce depressive symptoms. This is supported by a large body of research involving tens of thousands of people. You don't need a perfect diet, but making whole-of-diet changes is more effective than focusing on single nutrients.

High-fat Western diets promote gut dysbiosis characterized by increased Gram-negative bacteria, leading to metabolic endotoxemia (circulating LPS), systemic inflammation, and insulin resistance.

Reduce saturated fats and increase fiber intake. This shifts gut bacteria away from endotoxin-producing species, lowering circulating LPS and reducing the risk of insulin resistance and inflammation.

Physical activity based interventions specifically reduce the odds of gestational diabetes, whereas diet-based interventions do not show a significant reduction in gestational diabetes in IPD meta-analysis.

Engage in moderate physical activity during pregnancy. This specific type of intervention has been shown to reduce the risk of gestational diabetes.

High consumption of ultra-processed foods (defined as >4 servings daily) is independently associated with a 62% increased hazard of all-cause mortality compared to low consumption.

To lower your risk of early death, limit ultra-processed foods to less than 4 servings per day. Focus on reducing items like sugary drinks, processed meats, and packaged snacks, as these contribute most to the risk. Prioritize whole or minimally processed foods.

Each additional daily serving of ultra-processed food is associated with an 18% relative increase in all-cause mortality risk.

Track your daily servings of ultra-processed foods. Each extra serving adds 18% to your mortality risk. Reducing even one serving per day can significantly lower your long-term health risk.

Grip strength cutpoints of <26 kg for men and <16 kg for women identify clinically relevant weakness associated with mobility impairment (gait speed <0.8 m/s) in older adults.

To screen for mobility risk in older adults, measure grip strength. If a man's grip is below 26 kg or a woman's is below 16 kg, they are at significantly higher risk for slow walking and disability. This simple test helps identify who might benefit from strength interventions.

Sleep deprivation (defined as <6-7 hours/night or acute/chronic restriction) increases the risk of infectious diseases by impairing innate and adaptive immune responses, including reduced T-cell efficacy and antibody production.

Prioritize getting 7-8 hours of sleep nightly to maintain robust immune function. Chronic sleep restriction (<6 hours) significantly impairs your body's ability to fight off viruses and bacteria, making you more susceptible to respiratory infections and reducing the effectiveness of vaccines. Treat sleep as a critical health intervention, not optional downtime.

Muscle quality factors (composition, metabolism, fat infiltration, fibrosis, neural activation) are critical determinants of mobility and function in older adults, often preceding or occurring independently of muscle mass loss.

Don't just focus on building muscle size. As you age, prioritize exercises that improve muscle quality, such as resistance training for strength and power, and aerobic exercise for metabolic health. Be aware that factors like fat infiltration into muscles and neural efficiency play a huge role in your mobility, often more so than muscle size alone. Regular physical activity is the most effective way to maintain these qualities.

Performing squats to depths greater than 90 degrees of knee flexion does not increase ACL or PCL injury risk and may enhance joint stability through increased soft tissue constraint, while maximizing quadriceps and gluteus maximus activation.

If you have healthy knees, squatting deep (past parallel) is safe and likely better for your ligaments than stopping at 90 degrees. It also recruits more muscle. If you have specific knee pain or cartilage issues, consult a professional to determine your safe depth.

Adherence to a Mediterranean diet supplemented with extra-virgin olive oil (EVOO) significantly reduces the incidence of invasive breast cancer in postmenopausal women at high cardiovascular risk compared to a control low-fat diet.

If you are a postmenopausal woman with cardiovascular risk factors, incorporating extra-virgin olive oil as a primary fat source (aiming for roughly 1 liter per week distributed across your meals) into a Mediterranean-style diet may significantly lower your risk of developing invasive breast cancer. This benefit appears driven by the polyphenols and monounsaturated fats in the oil, rather than just calorie reduction. Focus on high-quality EVOO and use it to replace saturated fats, rather than adding it on top of an already high-fat diet.

Alcohol consumption is a direct cause of liver disease, with risk increasing linearly with dose, and binge drinking independently increases the risk of alcoholic liver disease (ALD) regardless of average daily consumption.

Alcohol causes liver damage in a dose-dependent manner. There is no universally 'safe' limit, but risk increases with higher doses and binge patterns. Women are particularly susceptible to lower thresholds of damage. Reducing alcohol intake and avoiding binge drinking are key strategies to prevent alcoholic liver disease.

Older adults (60-75 years) retain the capacity for significant myofiber hypertrophy in response to resistance training, effectively restoring type II fiber size to levels comparable to young adults, despite exhibiting smaller absolute hypertrophy gains than young men.

If you are over 60, you can still build significant muscle size with resistance training. While you might not grow as fast as a 25-year-old, your muscles will still get bigger, particularly the fast-twitch fibers responsible for power. Stick to a consistent 3-days-per-week schedule, focus on progressive overload (doing more weight or reps over time), and allow for adequate recovery, as your regenerative processes may be slower than younger individuals.

Obesity and diabetes are high-risk factors for severe coronavirus disease 2019 (Covid-19), leading to increased morbidity, mortality, and progression to respiratory failure.

If you have obesity or diabetes, you are at a significantly higher risk for severe Covid-19. This is due to factors like chronic inflammation, immune dysfunction, and lung mechanics. Ensure you are up to date on vaccinations and take precautions to avoid infection.

When muscle strength is normalized to body mass, obese individuals exhibit relative weakness compared to non-obese individuals, which contributes to functional limitations and disability risk.

Losing weight is often more effective for improving mobility than building muscle alone, because obesity creates a 'relative weakness' where your muscles are strong but not strong enough for your body weight. To improve function, you must either reduce the load (lose fat) or significantly increase muscle mass to improve the strength-to-weight ratio.

Repeated high-force eccentric exercise significantly reduces delayed-onset muscle pain and creatine kinase release in subsequent bouts, indicating an adaptation to muscle damage.

If you perform high-force eccentric exercises (like lowering weights slowly), expect significant muscle pain and stiffness after the first session. However, if you repeat the same exercise 2-3 times with 2-week intervals, the pain and muscle damage markers (like creatine kinase) will be significantly reduced in subsequent sessions. This adaptation does not increase your strength, but it does make the exercise more tolerable.

Consumption of non-digestible oligosaccharides (NDO), specifically inulin-type fructans, exerts a prebiotic effect by selectively stimulating the growth and activity of bifidobacteria and lactic acid bacteria in the human large intestine.

Eat 4-40 grams of inulin or oligofructose daily (found in chicory root, onions, garlic, bananas) to boost beneficial gut bacteria. You don't need massive doses; consistency matters more than quantity. This feeds bifidobacteria and lactic acid bacteria, improving gut flora balance.

Consumption of non-digestible oligosaccharides (NDO) improves bowel habit by increasing stool frequency and weight, providing relief from constipation.

Include NDO-rich foods (chicory, onions, garlic) in your diet to improve bowel regularity. If you are constipated, NDO can help normalize stool frequency and increase stool bulk by 1.5-2 grams per gram consumed. Start with moderate amounts to avoid initial gas.

Obese adults who are metabolically healthy face a substantially increased risk of developing type 2 diabetes compared to metabolically healthy normal-weight adults, contradicting the notion that healthy obesity is a harmless condition.

If you are obese but have normal blood pressure, cholesterol, and blood sugar, you are not 'off the hook' for diabetes risk. Your risk is still significantly higher than someone of normal weight with the same healthy markers. Focus on sustainable lifestyle changes to manage weight and metabolic health, rather than relying solely on current blood work results.

High-fat diet consumption induces gut microbiota dysbiosis (decreased Bacteroidetes, increased Firmicutes), which promotes obesity and chronic disease risk through enhanced energy harvest and gut permeability.

Focus on the quality of fats in your diet, not just the total calories. High-fat diets can alter your gut bacteria in ways that promote fat storage and inflammation. Reducing processed high-fat foods may help restore a healthier gut microbiome, potentially aiding weight management and reducing chronic disease risk.