Browse the evidence

In women, visceral adipose tissue (VAT) is significantly more strongly associated with insulin resistance and impaired insulin secretion than abdominal subcutaneous adipose tissue (SAT), whereas in men, both fat depots are associated with insulin resistance to a similar extent.

If you are a woman, carrying fat around your organs (visceral fat) is much more dangerous for your insulin sensitivity than carrying fat under your skin (subcutaneous fat). Men are less discriminating; both types of abdominal fat affect their insulin resistance similarly. Because waist size alone doesn't tell you where the fat is located, relying solely on it may underestimate metabolic risk in women. Focus on reducing overall adiposity, as visceral fat is the primary driver of insulin resistance in women.

Gender-affirming hormone therapy significantly reduces mental health morbidity, including depression and anxiety, in transgender individuals.

If you are transgender and experiencing significant distress related to your gender identity, accessing gender-affirming hormone therapy under medical supervision is strongly associated with significant improvements in mental health, including reduced depression and anxiety. While physical risks exist, they should be managed through careful monitoring and appropriate medication selection (e.g., transdermal estrogen for those at high thrombotic risk), as the mental health benefits are substantial.

Insomnia disorder is an independent risk factor for the development of mental health disorders, including depression, anxiety, and suicide, suggesting that treating insomnia may have preventive value for these conditions.

Treat insomnia seriously not just for sleep quality, but as a critical step in preventing depression and anxiety. Addressing sleep problems early may reduce the risk of developing these mental health conditions.

Digital Cognitive-Behavioral Therapy for Insomnia (dCBT-I) is a cost-effective and viable method for delivering CBT-I at scale, potentially reducing healthcare expenditures.

If you cannot access a therapist for CBT-I, look for validated digital CBT-I programs. They are increasingly recognized as cost-effective and can provide the same core therapeutic benefits.

Mineral deficiencies (specifically Magnesium, Zinc, Iron, Copper, and Selenium) impair immune competence by disrupting innate and adaptive immune cell function and inflammation regulation, whereas maintaining adequate levels through a balanced diet supports optimal immune defense.

Focus on eating a varied diet rich in vegetables, nuts, seeds, whole grains, and lean proteins to naturally cover your mineral needs. You likely do not need supplements unless you are in an at-risk group (like an athlete with a restricted diet, elderly, or pregnant) or have a diagnosed deficiency. If you do supplement, do so under medical guidance to avoid toxicity, as too much of certain minerals (like Iron or Zinc) can actually harm your immune system or feed pathogens.

Magnesium deficiency promotes a pro-inflammatory state by increasing cytokine production (IL-6, TNF-alpha) and oxidative stress, while adequate Magnesium levels help regulate inflammation and support T-cell function.

If you have chronic low-grade inflammation, check your Magnesium levels. Ensuring adequate intake through foods like spinach, nuts, and seeds may help lower inflammatory markers like CRP. Do not self-prescribe high-dose supplements without testing, as balance is key.

Zinc supplementation (>75 mg/day) significantly reduces the duration of common colds, and adequate Zinc status is critical for T-cell maturation and preventing thymic atrophy, though excessive doses (>40 mg/day long-term) can cause immune dysfunction.

If you catch a cold, starting Zinc lozenges or supplements (totaling >75mg/day) within 24 hours may shorten the illness. Do not take high-dose Zinc (over 40mg/day) as a daily long-term supplement, as it can harm your immune system and cause other health issues. Get your Zinc from food sources like beef, oysters, and nuts instead.

Cotadutide, a dual GLP-1 and glucagon receptor agonist, significantly improves hepatic parameters (AST, ALT, FIB-4, NFS, PRO-C3) and lipid profiles (triglycerides) in patients with type 2 diabetes and obesity, with effects on liver enzymes appearing independent of weight loss.

For individuals with type 2 diabetes and obesity, cotadutide (a dual GLP-1/glucagon agonist) offers significant improvements in liver health markers (like AST, ALT, and fibrosis scores) and triglyceride levels, potentially beyond what standard GLP-1 drugs like liraglutide achieve. This benefit appears linked to the glucagon component of the drug. Treatment involves daily subcutaneous injections, starting at a low dose and titrating up, which helps manage initial gastrointestinal side effects like nausea. Patients should discuss this option with their healthcare provider, especially if they have concerns about liver health or lipid profiles.

Implementing specific health taxes on sugar-sweetened beverages at rates of 20% or higher significantly reduces consumption and improves population health outcomes, whereas lower rates (<20%) generally fail to produce meaningful behavioral change.

To effectively reduce sugar-sweetened beverage consumption, policymakers must implement specific taxes that raise the shelf price by at least 20%. Lower taxes (under 20%) are ineffective because consumers do not react to small price increases, especially if the tax is not clearly visible on the shelf. To mitigate political backlash regarding the regressive nature of these taxes, revenues should be earmarked for health-related spending or subsidies for healthy foods.

Sleep restriction (4-5 hours/night) increases 24-hour energy expenditure by ~5-7% in humans, but this metabolic cost is offset by a disproportionate increase in caloric intake (particularly from post-dinner snacks), resulting in a positive energy balance and weight gain.

If you are sleeping less than 7 hours, do not assume you are burning more calories and can eat more. Your body burns slightly more energy when awake, but your hormones (ghrelin/leptin) drive you to eat significantly more, especially late at night. This extra food intake outweighs the extra energy burned, leading to weight gain. Prioritize 7-9 hours of sleep to protect your metabolic health.

Circadian misalignment (e.g., shift work, eating at night) decreases 24-hour energy expenditure and impairs glucose metabolism, independent of caloric intake and physical activity levels.

If you work night shifts or eat late at night, your body's metabolism is less efficient. Your energy expenditure drops, and your body handles sugar worse. To mitigate this, try to eat your main meals during your biological day (even if it's during your 'day' while working nights) and prioritize getting high-quality sleep during the day. Avoid eating large meals during your biological night.

Sleep restriction (4-5 hours/night) impairs glucose metabolism and insulin sensitivity to levels similar to those seen in pre-diabetic or diabetic populations.

Chronic sleep restriction (4-5 hours/night) can impair your body's ability to regulate blood sugar to levels seen in pre-diabetic individuals. This happens even if you maintain a healthy weight. Prioritize 7-9 hours of sleep to protect your long-term metabolic health and reduce your risk of type 2 diabetes.

Ultra-marathon running causes a significant energy deficit leading to reductions in both body fat and skeletal muscle mass.

If you are preparing for an ultra-marathon, expect to lose some muscle and fat due to the massive energy expenditure. To minimize muscle loss, prioritize high carbohydrate intake during the race and ensure adequate protein intake in the days following the event to support recovery.

Previous race experience, specifically the number of ultra-marathon finishes and personal best marathon time, is the most important predictor of successful ultra-marathon performance.

If you are new to ultra-running, prioritize completing shorter ultra-distances to gain experience. Your personal best marathon time and the number of ultras you have finished are better predictors of your future success than your current fitness level alone. Start with shorter ultras to build this specific experience.

Chronic sleep loss (defined as <6 hours or >8-9 hours per night) significantly increases the incidence of cardiovascular disease, including coronary heart disease and stroke, and is associated with incident diabetes, weight gain, and all-cause mortality.

Aim for 7-8 hours of sleep per night. Both sleeping less than 6 hours and more than 9 hours is associated with significantly higher risks of heart disease and stroke. Prioritizing sleep duration is as critical for long-term health as diet and exercise.

Higher Chinese visceral adiposity index (CVAI) is significantly associated with increased prevalence of cardiovascular disease (CVD) and diabetic kidney disease (DKD) in diabetic adults, independent of BMI.

For diabetic patients, tracking visceral fat risk via the Chinese Visceral Adiposity Index (CVAI) provides a more accurate prediction of heart and kidney disease risk than BMI alone. Clinicians should prioritize CVAI calculations to identify high-risk individuals for early intervention, particularly women who show a stronger association between CVAI and kidney disease.

Direct supplementation with EPA and DHA is significantly more effective for cardiovascular health and raising the n-3 index than consuming alpha-linolenic acid (ALA) from plant sources, due to the extremely low and variable bioconversion rate of ALA to EPA/DHA in humans.

If your goal is cardiovascular protection or raising your blood omega-3 levels, direct sources of EPA and DHA (from fish or algae supplements) are far more effective than relying on plant sources like flax or chia seeds. Your body converts very little of the plant-based ALA into the active EPA and DHA needed for these benefits. Vegans should prioritize algae-based EPA/DHA supplements to ensure adequate intake.

Stearidonic acid (SDA) is a more effective plant-based precursor for increasing EPA levels than alpha-linolenic acid (ALA) because it bypasses the rate-limiting delta-6-desaturase enzyme step in the conversion pathway.

If you cannot take fish or algae oil, look for supplements containing Stearidonic Acid (SDA) from sources like Echium plantagineum or Buglossoides arvensis (Ahiflower). These provide more EPA than equivalent amounts of standard flax or chia oil because they skip the hardest step of conversion in your body.

Genetic variants in the FADS1-2-3 gene cluster significantly reduce the bioconversion of ALA to EPA/DHA, making direct EPA/DHA supplementation necessary for populations with high prevalence of these variants (e.g., Americans, East Asians).

If you are of American or East Asian descent, your body is genetically less efficient at converting plant omega-3s (flax/chia) into active forms. You should prioritize direct sources of EPA and DHA (fish or algae oil) to ensure you get the benefits, whereas South Asian or African populations may have better conversion efficiency from plant sources.

Non-Hispanic Asian adults in the US experienced significant increases in all measured adiposity metrics (BMI, waist circumference, body fat percentage) and lean mass between 2011 and 2018.

Non-Hispanic Asian adults are experiencing rising adiposity. Monitor body fat percentage and waist circumference, as standard BMI may underestimate health risks. Consider adopting lower BMI cutoffs (≥27.5) for obesity classification if advised by a healthcare provider.

Environmental interventions that reduce the availability or increase the price of sugar-sweetened beverages (SSBs) significantly decrease SSB consumption and sales.

To reduce sugar-sweetened beverage intake, change the environment rather than relying on willpower. Make healthy drinks (water, diet) the default and easy to find, while making SSBs harder to find or more expensive. This works for individuals (home delivery of water) and communities (school policies, store promotions).

Higher gut microbial alpha diversity (Shannon index and richness) and a higher abundance of specific butyrate-producing bacterial taxa are associated with lower insulin resistance (HOMA-IR) and a lower prevalence of type 2 diabetes.

Maintaining a diverse gut microbiome, particularly one rich in butyrate-producing bacteria, is linked to better insulin sensitivity and a lower risk of Type 2 Diabetes. While this study is observational, it suggests that dietary strategies supporting microbial diversity (often associated with high-fiber, plant-rich diets) may support metabolic health.

Dietary habits are the dominant factor explaining inter-individual variation in the plasma metabolome, accounting for more variance than genetics or the gut microbiome for the majority of metabolites.

Your diet has a significantly larger impact on your blood metabolite levels than your genetics or gut bacteria do for most metabolic markers. Focusing on food quality and specific food items (like coffee or fish) can directly alter your metabolic profile more effectively than trying to change your genetic makeup.

Plasma metabolite levels can accurately predict an individual's diet quality score, reflecting the relationship between diet and disease.

You can use blood metabolite profiles to objectively assess your diet quality, providing a more accurate picture than self-reported food surveys alone.