Browse the evidence

Prebiotics and probiotics can positively modulate gut microbiota by increasing butyrate producers and reducing body fat, offering a potential alternative or adjunct to restrictive diets and surgery for improving metabolic outcomes.

If you are looking to support your gut health and potentially reduce body fat without drastic dietary changes or surgery, consider trying specific prebiotics and probiotics. The review suggests they can increase beneficial bacteria and reduce body fat, though results depend on the specific strain and duration of use.

High polygenic scores for obesity or type 2 diabetes significantly increase disease risk but are currently weak predictors of individual outcomes, necessitating the integration of lifestyle and environmental factors for accurate risk assessment.

Do not rely on direct-to-consumer genetic tests to predict your weight or diabetes risk. While you may have a higher genetic predisposition, these tests are currently poor predictors of individual outcomes. Focus on modifiable factors like diet, physical activity, and sleep, as these environmental factors interact with your genetics to determine your actual health status. Personalized care requires combining genetic insights with lifestyle data, not just genetics alone.

Females and males experience similar relative increases in muscle hypertrophy and lower-body strength when following the same resistance training protocol, but females exhibit a significantly larger relative increase in upper-body strength.

If you are a female starting resistance training, do not expect your absolute strength numbers to match males, but expect your relative improvements in upper-body strength to be greater than males. For muscle size and lower-body strength, your relative progress will be on par with males. Stick to the same training protocols used by males; you do not need a different program to see excellent results.

Hunter-gatherer populations exhibit very low prevalence of obesity and metabolic diseases (such as type 2 diabetes and hypertension) despite high physical activity levels, suggesting that lifestyle factors beyond simple energy balance (e.g., diet composition, pathogen load) are critical for metabolic health.

Adopting a lifestyle with high physical activity and whole-food diets can significantly reduce the risk of obesity, diabetes, and hypertension, even into old age. Focus on maintaining muscle mass and activity levels rather than fearing these diseases as inevitable.

Sleep irregularity, measured by the Sleep Regularity Index (SRI), is significantly associated with increased cardiometabolic risk, including higher 10-year atherosclerotic cardiovascular disease (ASCVD) risk, obesity, hypertension, and markers of type 2 diabetes (fasting glucose, HbA1c), independent of sleep duration.

Track your sleep consistency, not just duration. Use a wearable or app to calculate your Sleep Regularity Index (SRI) or simply aim to go to bed and wake up at the same time every day, including weekends. This consistency is linked to lower risks of heart disease, diabetes, and obesity, independent of how many hours you sleep.

Phase-sensitive 8-electrode segmental bioelectrical impedance analysis (BIA) provides high-accuracy predictions of whole-body and segmental skeletal muscle mass (SMM) comparable to MRI, with no significant difference in goodness-of-fit between standing and supine measurement positions.

For accurate tracking of muscle mass without expensive MRI scans, use a medical-grade, phase-sensitive, 8-electrode segmental BIA device. Ensure you follow the manufacturer's protocol for either standing or supine measurement, as both are equally accurate with this technology. Do not rely on simple wrist-ankle consumer scales for precise muscle mass estimation, as they are less accurate.

Higher adherence to a plant-based dietary index (high plant foods, low animal foods) is associated with lower longitudinal insulin resistance, lower risk of prediabetes, and lower risk of type 2 diabetes.

Adopt a diet that emphasizes plant foods (vegetables, fruits, whole grains, nuts, legumes) and reduces animal foods (meat, dairy, eggs). You do not need to be strictly vegan. Increasing your plant-based score by 10 units (e.g., more fruits/vegetables, less red meat) is associated with a 13-18% lower risk of developing type 2 diabetes and lower insulin resistance. Ensure your plant foods are high quality (whole grains, not sweets).

The A Body Shape Index (ABSI) provides superior mortality risk stratification compared to BMI and other waist indices (WC, WHR) because it is designed to be independent of BMI, allowing for the identification of high-risk individuals within all BMI categories, including underweight and obese groups.

Use the A Body Shape Index (ABSI) instead of just BMI or waist circumference to assess your mortality risk. ABSI accounts for your waist size relative to your height and weight in a way that BMI cannot. If you have a high ABSI, you are at higher risk of death regardless of whether you are underweight, normal weight, or obese. This metric helps identify people who might be missed by BMI alone, allowing for more personalized screening and monitoring.

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.

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.

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.

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.

Long-term shift work, particularly involving night shifts, is strongly associated with increased risks of cardiovascular disease, metabolic disorders (type 2 diabetes, metabolic syndrome), and gastrointestinal issues, largely mediated by circadian misalignment, sleep restriction, and adverse lifestyle behaviors.

If you work nights or rotating shifts, prioritize protecting your sleep environment (dark, cool, quiet) and manage light exposure (bright light during shift, dark glasses on commute home). Be mindful of meal timing; eating late at night can worsen metabolic risk. Recognize that fatigue and digestive issues are common physiological responses to circadian disruption, not just personal failings, and consider strategies to align your schedule with your body's clock where possible.

In individuals with chronic kidney disease (CKD), the presence of sarcopenia (defined by low muscle strength, mass, or performance) significantly increases the risk of all-cause mortality and progression to end-stage renal disease (ESRD).

If you have chronic kidney disease, having low muscle strength or mass is a serious warning sign that increases your risk of death and needing dialysis. You should get your muscle strength checked (e.g., handgrip test) and prioritize physical activity, as it is one of the most effective ways to counteract muscle loss and improve your prognosis.

High-intensity interval training (HIIT) is relatively safe for patients with coronary artery disease or heart failure when administered within supervised cardiac rehabilitation settings, with a major adverse cardiovascular event rate of 1 per 17,083 training sessions.

If you have stable heart disease or heart failure, high-intensity interval training is likely safe when done in a supervised cardiac rehab program. The risk of a serious heart event is extremely low (about 1 in 17,000 sessions). Do not attempt this unsupervised; ensure your condition is stable and you are monitored by cardiac staff.

A high pre-treatment Prevotella-to-Bacteroides (P/B) ratio predicts significantly greater body fat loss when consuming a high-fiber, whole-grain diet (New Nordic Diet) compared to a standard diet, whereas individuals with a low P/B ratio show no such differential benefit.

If you are trying to lose fat using a high-fiber, whole-grain diet, your gut bacteria composition matters. A simple test of your Prevotella-to-Bacteroides ratio can predict success: if your ratio is high, you are likely to lose significant fat on this diet; if it is low, you may not see benefits over a standard diet, suggesting you might need a different nutritional approach.

Better self-reported sleep quality is associated with better mental health outcomes, specifically showing a U-shaped relationship where both short and long sleep durations correlate with higher depression and anxiety.

Prioritize sleep quality over just duration. If you are sleeping 7-9 hours but still experience high anxiety or depression, your sleep efficiency or continuity may be poor. This study suggests that poor sleep quality is strongly linked to mental health issues, regardless of age. Aim for consistent, efficient sleep rather than just time in bed, and be aware that both sleeping significantly less or significantly more than average can negatively impact mental well-being.

Poor sleep quality is modestly but consistently associated with poorer cognitive performance, particularly verbal phonemic fluency, across the entire adult lifespan (18-98 years).

Maintain good sleep hygiene throughout your life, not just as you age. This study shows that poor sleep quality consistently impacts cognitive performance, especially verbal fluency, from young adulthood to old age. Prioritizing sleep is a key strategy for maintaining cognitive health at any age.

Consumption of polyphenol-rich foods (e.g., fruits, vegetables, tea, cocoa) alters gut microbiota composition by promoting beneficial bacteria (Lactobacillus, Bifidobacterium) and inhibiting harmful pathogens, thereby reducing inflammation and improving metabolic health.

Increase your intake of polyphenol-rich foods such as berries, dark chocolate, green tea, and olive oil. These compounds feed beneficial gut bacteria like Lactobacillus and Bifidobacterium while inhibiting harmful ones. This process reduces inflammation and supports metabolic health, even if the polyphenols themselves are processed by gut bacteria rather than directly absorbed.

The Western diet, high in refined carbohydrates, saturated fats, and low in fiber, disrupts gut microbiota diversity and increases the risk of obesity, cardiovascular disease, and metabolic syndrome.

Avoid the Western diet pattern, which is high in refined carbs, saturated fats, and low in fiber. This diet is linked to obesity, cardiovascular disease, and metabolic syndrome. Instead, focus on whole foods, high fiber, and healthy fats to support gut health and reduce disease risk.

High-Intensity Interval Training (HIIT) is an essential component for enhancing endurance performance in athletes, though the optimal intensity distribution and specific prescription remain unclear.

For endurance athletes, HIIT is non-negotiable for performance gains, but you must balance it with moderate volume. Do not prescribe HIIT in isolation; integrate it into a broader program (pyramidal or polarized) to avoid overtraining. The exact type of HIIT (short vs. long intervals) should be periodized based on the specific sport and competition phase.

Postoperative sleep disturbances, characterized by fragmentation and loss of deep/REM sleep, significantly increase the risk of postoperative delirium, cardiovascular events, and delayed recovery.

Recognize that poor sleep after surgery is not just 'being tired' but a clinical risk factor for confusion (delirium) and heart issues. Advocate for sleep-promoting measures like minimizing night interruptions, using earplugs/eye masks, and discussing sleep aids with the medical team.

Pharmacological interventions including zolpidem, melatonin, and dexmedetomidine can improve postoperative sleep quality and reduce complications like delirium.

Ask your care team about sleep-promoting medications like dexmedetomidine or melatonin, especially if you are elderly or in the ICU, as they may help prevent confusion and improve recovery.

Nonpharmacological interventions such as regional anesthesia, noise reduction, and use of earplugs/eye masks improve postoperative sleep quality.

Request earplugs and eye masks from nursing staff to block out hospital noise and light, which are major disruptors of sleep architecture.