Browse the evidence

High psychological distress (stress, anxiety, depression) during COVID-19 lockdown significantly increases the probability of poor sleep quality in adults.

If you are experiencing high levels of stress, anxiety, or depression during a crisis, prioritize sleep hygiene immediately. The data shows that severe distress drastically increases the odds of poor sleep. Managing your mental state is not just about mood; it is a direct physiological lever for protecting your sleep quality.

Disruptions to circadian rhythms, specifically changes in habitual bedtime (earlier or later) and awakening time, are significant risk factors for poor sleep quality during lockdown.

Maintain consistent bedtimes and wake times, even when working from home. The data shows that shifting your sleep schedule (either earlier or later) significantly increases the risk of poor sleep. Regularity is more important than total hours when it comes to sleep quality.

Acute exercise induces a transient suppression of appetite (exercise-induced anorexia) and does not stimulate compensatory increases in energy intake on the day of exercise, regardless of whether the individual is lean or has overweight/obesity.

You can exercise to create a calorie deficit without worrying that you will automatically eat back the calories burned on the same day. While you might feel less hungry during and immediately after the workout, this effect is temporary and does not lead to overeating later. This holds true whether you are lean or have overweight/obesity.

Roux-en-Y gastric bypass (RYGB) provides superior long-term type 2 diabetes (T2DM) remission, lower relapse rates, and better glycemic control compared to sleeve gastrectomy (SG) in real-world clinical settings.

If you have Type 2 Diabetes and are considering bariatric surgery, Roux-en-Y Gastric Bypass (RYGB) is associated with better long-term diabetes remission and lower relapse rates compared to Sleeve Gastrectomy (SG). While SG is a common procedure, RYGB may offer superior metabolic benefits for diabetes management, though it involves a more complex surgery. Discuss these long-term outcomes with your surgeon to make an informed choice.

Large-scale food fortification and biofortification are highly cost-effective public health interventions that significantly reduce micronutrient deficiencies (anemia, vitamin A deficiency, iodine deficiency) and associated health burdens in low- and middle-income countries.

For public health policymakers in LMIC: Implement mandatory fortification of staple foods (wheat, maize, rice, salt, sugar, oil) with essential micronutrients (iron, iodine, vitamin A, folic acid). Ensure strong government enforcement, quality control, and monitoring to guarantee compliance. This is one of the most cost-effective ways to improve population health, reduce anemia, prevent birth defects, and boost economic productivity.

Low energy availability (EA <30 kcal/kg FFM/day) causes functional hypothalamic amenorrhea (FHA) in female athletes through suppressed GnRH pulsatility, leading to decreased estradiol and progesterone.

If you are a female athlete experiencing missed periods, check your energy intake relative to your exercise expenditure. If your energy availability is consistently below 30 kcal per kg of fat-free mass per day, you are at high risk for hormonal suppression. Consult a specialist to address this before bone health is compromised.

Low energy availability reduces resting metabolic rate (RMR) by approximately 8% as an energy-conserving mechanism, independent of changes in body composition.

If you are training heavily and eating very little, your body may slow down its baseline calorie burn to survive. This is a normal adaptation, not a broken metabolism. Restoring adequate energy intake will help normalize your metabolic rate.

Low energy availability suppresses leptin levels and elevates ghrelin and peptide YY (PYY), disrupting appetite regulation and contributing to the maintenance of low energy states.

Low energy intake changes your hunger hormones: leptin drops, ghrelin and PYY rise. This can make it harder to feel hunger cues accurately and may contribute to disordered eating patterns. Prioritize regular, adequate meals to normalize these hormones.

Low energy availability leads to decreased IGF-1 and increased GH, indicating GH resistance at the liver, which impairs bone and muscle anabolism.

If you are under-fueled, your body may produce more GH but fail to use it effectively (GH resistance), leading to low IGF-1. This impairs bone and muscle health. Restoring energy intake can help normalize this axis.

Baseline malnutrition, diagnosed via GLIM or ESPEN criteria, is a strong predictor of developing sarcopenia or severe sarcopenia within four years in community-dwelling older adults.

If you are an older adult, your nutritional status is a key predictor of whether you will lose muscle mass. Being malnourished (defined by criteria like low BMI, weight loss, or low muscle mass) increases your risk of developing sarcopenia by 3-4 times over four years. Focus on maintaining adequate nutrition, including protein intake, as a primary strategy to prevent muscle loss, rather than viewing muscle loss as inevitable.

Selenium deficiency alters gut microbiota composition and function, leading to a phenotype that increases susceptibility to cancer, thyroid dysfunction, inflammatory bowel disease, and cardiovascular disorders.

Ensure adequate selenium intake through diet (e.g., Brazil nuts, seafood, meat) or supplementation if deficient, as this supports a healthy gut microbiota which protects against chronic diseases like cancer and cardiovascular disorders.

In conditions of limited selenium supply, intestinal bacteria compete with the host for selenium, reducing host selenoprotein levels by two to three times.

If you have low selenium levels, be aware that your gut bacteria may compete for it. Ensuring adequate selenium intake through diet or supplementation can help maintain your own selenoprotein levels.

High-dose selenium supplementation (200 µg/day) as selenized yeast or L-selenomethionine has shown mixed results in cancer prevention trials, with some showing reduced risk and others showing no benefit or increased risk.

Selenium supplementation (200 µg/day) has shown mixed results in cancer prevention. It may be beneficial in some populations (e.g., those with low baseline selenium) but not others. Consult a healthcare provider for personalized advice.

Fat oxidation during aerobic exercise is maximized at moderate intensities (approximately 60-65% VO2max) and decreases significantly at higher intensities (>75% VO2max) due to the Randle cycle and reduced plasma fatty acid availability.

To maximize the rate of fat oxidation, exercise at a moderate intensity, roughly 60-65% of your maximum oxygen uptake (VO2max). This is often described as a 'conversational pace.' Pushing into high-intensity zones shifts your body to burn more carbohydrates and less fat, even if you burn more total calories.

Endurance training increases maximal fat oxidation (MFO) and shifts the intensity at which MFO occurs to higher workloads, primarily through increased intramuscular triglyceride (IMTG) utilization and mitochondrial density.

If you train for endurance, your body becomes more efficient at burning fat. This is due to increased mitochondrial density and greater storage of fat within muscles (IMTG). This adaptation allows you to burn more fat at higher intensities than an untrained person.

Dietary fiber is a more reliable predictor of satiety and metabolic health than Glycemic Index, as low-GI diets often derive their benefits from higher fiber content rather than the glycemic response itself.

Prioritize fiber over Glycemic Index. If you are choosing between carbohydrate sources, pick the one with more fiber (vegetables, legumes, whole grains) rather than worrying about whether it spikes blood sugar quickly. High-fiber foods naturally promote fullness and better metabolic markers, making the GI calculation unnecessary for most people.

Vitamin D and 4-pyridoxic acid (Vitamin B6 metabolite) levels are significantly lower in the luteal and periovulatory phases, potentially increasing susceptibility to mood disorders like PMS by limiting neurotransmitter synthesis precursors.

Vitamin D and Vitamin B6 (as 4-pyridoxic acid) levels drop during the luteal and periovulatory phases. Since these vitamins are cofactors for neurotransmitter synthesis (serotonin, GABA), this drop may contribute to PMS/PMDD symptoms. Ensuring adequate intake of these nutrients, particularly during the second half of the cycle, may support mental health.

Ketogenic diets provide short-term improvements in seizure frequency, weight loss, and glycemic control, but these benefits are often temporary and outweighed by long-term risks including nutrient deficiencies, adverse lipid profiles, and increased chronic disease risk.

If you try a ketogenic diet, expect short-term improvements in weight and blood sugar, but do not expect it to be superior to other healthy diets in the long run. Be aware that you may experience nutrient deficiencies, increased LDL cholesterol, and other health risks. For most people, the long-term risks outweigh the short-term benefits.

Simple, high-contrast front-of-package warning labels (specifically black-and-white stop signs with 'High in' text) significantly improve consumer visualization, understanding, and intention to modify purchase behavior compared to complex or positive-framing labels.

For policymakers and public health advocates: Implement mandatory, high-contrast front-of-package warning labels (e.g., black-and-white stop signs with 'High in [Nutrient]'). Avoid complex traffic-light systems or positive-only labels, as evidence shows they are less understood and less effective at modifying purchase behavior, especially among low-SES populations. Simplicity and visual salience are key to driving healthier food choices.

Step intensity (cadence) is positively correlated with step count and independently associated with lower risk of chronic diseases, though the relationship is less consistent than step count alone.

While total steps are the primary driver, walking faster (higher cadence) adds additional benefit. However, you do not need to obsess over speed; simply increasing your total daily steps will likely increase your average cadence and provide protection.

Omega-3 polyunsaturated fatty acids (EPA, DHA, DPA) exert anti-inflammatory and pro-resolving effects by being metabolized into specialized pro-resolving mediators (SPMs) such as resolvins, protectins, and maresins, which actively terminate inflammation and promote tissue regeneration rather than merely suppressing immune responses.

Consuming omega-3 fatty acids (EPA, DHA, DPA) supports the body's active resolution of inflammation through specialized mediators like resolvins and protectins. This process helps clear cellular debris, promotes tissue regeneration, and regulates immune responses, offering a pathway to manage chronic inflammatory states associated with diseases like cardiovascular issues and autoimmune disorders.

Nicotinamide Riboside (NR) supplementation at doses up to 1000 mg/day for 8 weeks significantly increases whole blood NAD+ levels in a dose-dependent manner without causing flushing or elevating LDL cholesterol in healthy overweight adults.

If you are looking to boost NAD+ levels, taking Nicotinamide Riboside (NR) between 100mg and 1000mg daily for 8 weeks is a safe and effective strategy for healthy overweight adults. You can expect a significant increase in blood NAD+ (up to 140% at the highest dose) without the flushing side effects of Niacin or negative impacts on cholesterol. Start with a lower dose (100-300mg) to assess tolerance, though the study found all doses well-tolerated.

Dietary fiber (specifically fermentable fibers like pectin) reduces the production of indole, a precursor to the uremic toxin indoxyl sulfate, by triggering catabolite repression of the tnaA gene in indole-producing gut bacteria (e.g., E. coli).

To support gut health and potentially reduce the production of harmful metabolites like indole, incorporate fermentable fibers (such as pectin found in apples) into your diet. This encourages beneficial bacteria to produce protective metabolites (ILA, IPA) and suppresses the production of indole, which is linked to chronic kidney disease risk.

During pandemic lockdowns, adults and adolescents globally shifted toward modified eating behaviors characterized by increased snack frequency, higher consumption of sweets and ultra-processed foods, and decreased adherence to healthy diets (fruits/vegetables).

Pandemic lockdowns and restrictive measures led to a global shift in eating behaviors, with people consuming more snacks, sweets, and ultra-processed foods while eating fewer fruits and vegetables. This resulted in decreased adherence to healthy diets and increased alcohol consumption across various demographics.