Browse the evidence

Longitudinal sleep trajectories characterized by consistently short sleep (<5 hours) or decreasing sleep duration are associated with significantly increased risks of cardiovascular events and all-cause mortality compared to stable normal sleep (7-8 hours).

Monitor your sleep duration over time, not just on a single night. If you consistently sleep less than 5 hours a night, or if your sleep duration is steadily decreasing over months or years, you are at a significantly higher risk for heart disease and early death. Aim for a stable 7-8 hours of sleep. If you are experiencing a decline in sleep, investigate underlying causes (stress, health issues) and seek medical advice, as this pattern is a strong predictor of adverse health outcomes.

Polysomnography (PSG) is an essential component of the preoperative workup for patients undergoing bariatric surgery because clinical parameters (BMI, neck circumference, Epworth Sleepiness Scale) are inadequate predictors of Obstructive Sleep Apnea (OSA).

If you are having weight loss surgery, do not skip the sleep study. Feeling tired or having a large neck does not reliably tell you if you have sleep apnea. You need a full night sleep study (PSG) before surgery to ensure you are safe during anesthesia and recovery.

Skeletal muscle mass measured via D3-creatine dilution is a strong predictor of functional capacity, mobility limitations, and injurious falls in older adults, whereas lean body mass measured by DXA is only weakly or not associated with these outcomes.

If you are assessing muscle health in older adults, standard DXA scans may underestimate the risk of falls and disability because they include non-muscle tissue in 'lean mass'. Accurate assessment of functional muscle mass (via D3-creatine dilution in research settings) reveals that muscle mass is a critical driver of mobility. For clinical practice, this implies that relying solely on DXA lean mass may miss high-risk individuals who have low functional muscle mass despite normal lean mass readings.

The joint use of Body Mass Index (BMI) and A Body Shape Index (ABSI) provides a significantly better assessment of cardio-metabolic risk factors (high triglycerides, low HDL, high fasting glucose) and visceral adipose tissue (VAT) thickness than using BMI alone.

If you are assessing metabolic health, do not rely on BMI alone. Calculate your A Body Shape Index (ABSI) using your waist circumference, height, and weight. Using both BMI and ABSI together provides a much more accurate picture of your risk for high triglycerides, low HDL, and high blood sugar than BMI by itself. This is especially important if you have a 'normal' BMI but carry weight around your midsection.

Native inulin supplementation (16g/day) combined with dietary advice to consume inulin-rich vegetables promotes greater weight loss and metabolic improvements in obese patients compared to placebo, but this efficacy is significantly compromised by concurrent metformin treatment.

If you are obese and not taking metformin, adding 16g of native inulin daily (starting with 8g for the first week) along with eating more inulin-rich vegetables (like garlic, onions, and artichokes) and eating 30% fewer calories can help you lose more weight and improve metabolic markers than just dieting alone. However, if you are already taking metformin, this specific supplement may not offer the same benefits, so discuss this with your doctor before starting.

Plant-based meat alternatives (PBMAs) often have higher sodium and saturated fat content than conventional meat, and their health benefits are largely inferred from traditional plant-based diets rather than direct evidence on the processed products themselves.

If you are switching to plant-based meats for health, read the label. They often have much more sodium than regular meat. For better health outcomes, prioritize whole plant proteins like beans, lentils, and tofu over highly processed meat alternatives.

Substituting animal meat with plant-based meat alternatives (PBMAs) may improve cardiovascular risk factors like TMAO levels, but may also negatively impact bone health markers compared to meat consumption.

If you switch to plant-based meats, monitor your overall diet. While it might help some heart health markers, it may not support bone health as well as meat. Ensure you are getting enough calcium and vitamin D from other sources.

Performing intense aerobic exercise prior to resistance training does not compromise muscle hypertrophy or strength gains and may actually enhance muscle volume increases compared to resistance training alone.

If you want to build muscle and improve cardiovascular health, you can do cardio before your weight training without worrying about losing muscle gains. In fact, this study suggests you might actually build more muscle volume by doing so. Just make sure to wait about 6 hours between your cardio and weight sessions, and perform the cardio intensely enough to challenge yourself.

Higher velocity loss thresholds (20% and 40%) during resistance training maximize muscle hypertrophy compared to lower thresholds (0% and 10%), but excessive velocity loss (40%) induces negative neuromuscular adaptations such as slowed contraction delay and reduced early rate of force development.

For muscle growth, stop your sets when your bar speed drops by about 20% from your fastest rep. This gives you the best hypertrophy benefits without slowing down your muscle's ability to produce force quickly. Avoid stopping sets when speed drops by 40%, as this can hurt your power output. For strength, any moderate velocity loss (10-20%) works well, so prioritize technique and speed over total volume.

Monitoring accumulated training and match load in football is essential for controlling training demands, optimizing physiological adaptations, and guiding individual athlete performance, yet no consensus exists on the most effective monitoring system or metrics.

Track both external load (distance, speed zones via GPS) and internal load (heart rate, sRPE) across the entire week, not just match days. Since there is no single 'best' metric, consistency in how you measure load week-to-week is more important than the specific device used. Focus on the cumulative effect of training sessions, which make up 80% of the weekly load, to guide individual performance.

Saturated fatty acids (SFAs) promote inflammation and insulin resistance by activating the NLRP3 inflammasome and NF-κB pathways, whereas unsaturated fatty acids (UFAs) like EPA/DHA can inhibit these pathways.

The type of fat you eat matters for inflammation. Saturated fats (like palmitate) can trigger inflammatory pathways (NLRP3) and worsen insulin resistance. In contrast, unsaturated fats, particularly omega-3s (EPA/DHA), can help prevent this inflammation. Prioritize unsaturated fats for metabolic health.

Dietary supplements are generally safe and pose significantly lower risks of adverse events, hospitalizations, and fatalities compared to prescription drugs and even common foods.

You do not need to fear that taking a standard dietary supplement will cause you to end up in the emergency room or suffer a fatal outcome. The data shows that serious adverse events from supplements are extremely rare compared to prescription medications and even foodborne illnesses. However, you should still choose products from reputable manufacturers that undergo third-party testing (like NSF or Informed Choice) to ensure purity and avoid adulterated products.

Milk consumption is highest in older adults and specific regions (Central Latin America, Europe), while fruit juice consumption is highest in Australasia and high-income North America, with all three beverage categories being lowest in East Asia and Oceania.

If you are older, you likely consume more milk, which is a key source of calcium and vitamin D. If you live in East Asia or Oceania, your intake of all major non-alcoholic caloric beverages (SSBs, juice, milk) is among the lowest globally. Adjust your intake based on regional norms and age-related nutritional needs.

Scientific articles regarding the health effects of soft drinks, juice, and milk that are funded exclusively by the food/beverage industry are significantly more likely to conclude favorably for the sponsor's product compared to articles with no industry funding.

When evaluating health claims about soft drinks, juice, or milk, prioritize research that did not receive funding from the beverage industry. Industry-funded studies are significantly more likely to report favorable health outcomes for the sponsored product, suggesting a high risk of sponsorship bias.

Systematic reviews on sugar-sweetened beverages (SSBs) and weight gain that disclose financial conflicts of interest with food or beverage industries are five times more likely to conclude there is no positive association between SSB consumption and weight gain compared to reviews without such conflicts.

When evaluating health advice about sugary drinks, check who funded the research. If the study or review was funded by a beverage or food company, be skeptical of conclusions that claim these drinks do not contribute to weight gain. Independent research is more likely to find a link between SSB consumption and weight gain.

Global dietary quality, measured by the Alternative Healthy Eating Index (AHEI), is modest (mean score 40.3/100) and has improved only slightly (+1.5 points) globally between 1990 and 2018, with significant regional disparities where South Asia and Sub-Saharan Africa saw no improvement or decline.

Your overall diet matters more than any single food. Globally, average diet quality is low (40/100). To improve, focus on increasing fruits, vegetables, whole grains, and healthy fats while reducing sugar-sweetened beverages, red/processed meat, and sodium. This applies to everyone, but the specific gaps vary by region and education level. In many areas, simply increasing produce intake yields the biggest health return.

Two weeks of unilateral limb immobilization induces a coordinate down-regulation of mitochondrial bioenergetic and carbohydrate metabolism pathways in human skeletal muscle, leading to significant reductions in muscle strength and cross-sectional area.

If you must immobilize a limb (e.g., cast, brace) for two weeks, expect significant strength and size loss, driven largely by a shutdown of mitochondrial energy production. This metabolic suppression happens very early (within 48 hours). To mitigate this, active rehabilitation of the non-immobilized limb and nutritional strategies supporting mitochondrial health may be considered, though the primary intervention is minimizing immobilization time.

Protein ubiquitination and the expression of atrogenes (atrogin-1, MuRF-1) are significantly increased early (48 hours) during immobilization but return to baseline levels by 14 days, suggesting a transient role for this pathway in short-term human muscle atrophy.

Early in an injury period (first 2 days), your body may ramp up protein breakdown markers, but this does not necessarily mean muscle loss continues at the same rate or via the same mechanism after the first week. The body shifts focus to metabolic down-regulation.

Macroscopic increases in muscle size (hypertrophy) do not necessarily reflect proportional increases in contractile (myofibrillar) protein; instead, they often result from sarcoplasmic expansion (fluid, glycogen, non-contractile proteins), leading to a dilution of myofibrillar protein concentration.

When you see muscle size increase, do not automatically assume it is all 'quality' contractile tissue. A significant portion of early or even chronic hypertrophy can be 'sarcoplasmic'—driven by fluid, glycogen, and non-contractile proteins. This means your strength-to-size ratio might not improve as much as your tape measure suggests. Focus on strength metrics and protein synthesis markers, not just visual size, to gauge true contractile adaptation.

A Body Shape Index (ABSI) is a stronger predictor of all-cause mortality than BMI, waist circumference, waist-to-height ratio, or waist-to-hip ratio, with higher ABSI correlating to increased death rates.

Use the Body Shape Index (ABSI) instead of just BMI or waist circumference to assess your long-term mortality risk. ABSI is calculated using your height, weight, and waist circumference. A higher ABSI indicates a higher risk of death, independent of your BMI. While more complex to calculate than BMI, it offers a more accurate prediction of health outcomes by specifically targeting abdominal obesity relative to body size.

ABSI remains a consistent predictor of mortality hazard over long-term follow-up (at least 20 years), whereas the predictive power of other metrics may not be as persistent.

ABSI is a reliable long-term predictor of mortality risk, remaining significant for at least 20 years after measurement. This makes it a valuable tool for long-term health assessment, unlike some other metrics that may lose predictive power over time.

Food Balance Sheets (FBS) and household surveys systematically overestimate true individual nutrient intake due to waste, processing losses, and non-consumption allocation, making supply data a theoretical upper bound rather than a consumption measure.

When evaluating global nutrition reports, remember that 'supply' is the maximum possible intake, not what people actually eat. In developing nations, actual nutrient intake is likely lower than reported supply data suggests due to waste and processing losses.

Individuals with Medicare, dual-eligible insurance, lower education, older age, and male sex bear the highest annual diet-related CMD costs.

Targeted interventions for older adults, men, those with lower education, and those with public insurance (Medicare/dual-eligible) could yield significant cost savings. Focus on increasing nuts, seeds, and seafood omega-3s, and reducing processed meats, sodium, and SSBs.

High dietary dissimilarity (variety of food attributes) is associated with greater gain in waist circumference and does not reduce the risk of type 2 diabetes, refuting the notion that 'eating everything in moderation' improves metabolic health.

Do not assume that eating a wide variety of foods is automatically healthy. If your 'variety' includes many processed, high-sodium, or high-sugar foods, it may lead to abdominal fat gain and higher diabetes risk. Focus on the quality of the foods you eat, not just the number of different types. High dietary dissimilarity (eating many different types of foods with different attributes) was linked to worse metabolic outcomes in this study.