Browse the evidence

Higher plasma levels of the gut microbiome-derived metabolite Trimethylamine-N-oxide (TMAO) are associated with a significantly higher risk of incident atherosclerotic cardiovascular disease (ASCVD) in a diverse, community-based population free of prior cardiovascular disease.

This study suggests that higher levels of TMAO, a byproduct of gut bacteria processing nutrients like red meat and eggs, are linked to a higher risk of heart disease. While it doesn't tell you to eliminate these foods, it highlights the importance of your gut health and kidney function. If you have risk factors for heart disease, discussing your diet and TMAO levels with your doctor might be worthwhile, especially if you have reduced kidney function.

Muscle typology (determined by muscle carnosine levels) does not explain inter-individual variability in resistance training-induced increases in muscle volume, maximal dynamic strength, or fiber cross-sectional area when training is performed to failure at 60% 1RM.

If you are new to resistance training, your muscle fiber type (whether you are naturally 'fast' or 'slow') does not determine how much muscle or strength you will gain. As long as you train to failure with a moderate load (around 60% of your max), you will see similar improvements regardless of your genetics. Focus on consistency and effort rather than trying to tailor your program to your fiber type.

Timing of creatine ingestion (pre- vs. post-exercise) does not significantly influence gains in muscle mass or strength compared to resistance training alone.

Take your creatine whenever is most convenient for you. Whether you take it before or after your workout makes no measurable difference to your muscle growth or strength gains. Focus on taking it consistently every day rather than stressing about the exact timing.

Using velocity loss (VL) thresholds to prescribe or monitor resistance training volume for free-weight back squats is flawed and should not be used because the relationship between velocity loss and repetitions completed to failure lacks stability and predictive validity across sessions.

Do not use velocity loss thresholds to determine how many reps to perform in free-weight back squats. The relationship between how fast you move and how many reps you can do is too unstable from session to session to be useful for programming. Stick to traditional methods like RPE or fixed rep ranges.

Current precision nutrition tools based on Polygenic Risk Scores (PRS) have limited predictive power because they often fail to account for gene-environment interactions.

Do not rely solely on genetic testing for dietary advice. Current genetic risk scores are incomplete because they ignore your lifestyle. For accurate precision nutrition, genetic data must be combined with environmental factors like diet and activity.

Using the Glycemic Index (GI) as a primary indicator for carbohydrate quality fails to improve diet quality or Dietary Guidelines adherence because it ignores nutrient density and food context.

Stop using Glycemic Index (GI) labels or lists to guide your daily food choices. The GI ignores nutrient density and doesn't predict how your body reacts to mixed meals. Instead, focus on the Dietary Guidelines for Americans: eat nutrient-dense foods (vegetables, fruits, whole grains, legumes) in appropriate portions. This approach is more reliable for health than chasing low GI numbers.

Acute exercise (both HIIT and MICT) results in more phosphosite down-regulation than up-regulation, suggesting that acute exercise involves the inhibition of kinase activity and/or activation of phosphatases.

Exercise doesn't just turn things on; it also turns things off. This balance is crucial for adaptation. Don't assume more activation is always better; regulation (inhibition) is part of the process.

Tirzepatide has surpassed semaglutide as the most commonly prescribed first-time GLP-1 RA medication in the US as of September 2025.

Tirzepatide is now the most frequently prescribed first-time GLP-1 medication in the US, overtaking semaglutide. This reflects changing prescribing preferences among physicians.

Lean individuals with Metabolic Dysfunction-Associated Fatty Liver Disease (lean-MAFLD) face a significantly higher risk of liver-related mortality compared to overweight or obese MAFLD patients, despite having equivalent metabolic profiles and similar risks for extrahepatic mortality.

If you are lean but have been diagnosed with fatty liver (MAFLD), do not assume you are safe because you are thin. Your risk of liver-related death is actually higher than that of obese patients with the same condition. Standard weight loss advice, especially rapid loss via drugs, can be dangerous for you because it strips away muscle, which your liver needs. Focus on metabolic health markers (blood pressure, glucose, lipids) and consult your doctor about treatments that preserve muscle mass rather than just focusing on weight loss.

Personalized diet advice based on single or few continuous glucose monitor (CGM) measurements of duplicate meals is unreliable in adults without diabetes because within-subject glycemic variability for identical meals is similar to variability for different meals.

Do not make permanent dietary changes based on a single CGM reading of one meal. Your body's response to the exact same meal can vary significantly from day to day due to factors like sleep, stress, and activity. If you use a CGM, look for broad patterns over weeks (e.g., 'plant-based diets generally lower my glucose') rather than trying to identify specific 'bad' foods based on one spike. Reliable personalization requires aggregating many repeated measurements, not just one or two.

Biliopancreatic diversion with duodenal switch (BPD/DS) and its variants (SADI, TB) provide superior weight loss compared to Sleeve Gastrectomy (SG) and Roux-en-Y Gastric Bypass (RYGB) in extreme obesity, but at the cost of higher early complication rates and malnutrition risk.

For extreme obesity, malabsorptive surgeries like BPD/DS or SADI provide the best weight loss (38%+), significantly better than SG (23%) or RYGB (26%). However, these come with higher early complication rates (12.9% vs 4-8%). SG is safer but less effective for weight loss, making it a good option for older/younger patients or as a first step.

Higher AMY1 gene copy number does not significantly modify the risk of cardiovascular disease or mortality associated with starch intake.

You do not need to test your AMY1 gene copy number to determine your starch intake. Standard moderate starch intake recommendations likely apply to you regardless of your genetic makeup regarding amylase.

Repeated or substantial weight loss (≥5 kg, especially >10 kg or ≥3 episodes) is associated with significantly increased all-cause and cardiovascular mortality in men, but not in women.

If you are a man, be cautious about repeated, large weight loss cycles (especially >10kg or 3+ times). This study links such patterns to higher heart and overall mortality risk. Women in this study did not show the same risk. Focus on maintaining a stable, healthy weight rather than repeated drastic losses, and consult a doctor if weight loss is unintentional.

Repeated weight loss (≥3 episodes of ≥5 kg) is associated with increased all-cause and cardiovascular mortality, regardless of the total amount lost in a single episode.

If you have lost weight 3 or more times (even if each time was 5kg), your risk of heart disease and early death may be higher than if you had never lost weight. Try to maintain a stable weight rather than cycling up and down.

A single acute bout of resistance exercise training (RET) does not induce mitochondrial remodelling (biogenesis, content, or quality control) in either untrained older adults or master athletes within the acute (1h) or delayed (48h) recovery periods.

If you are an older adult or a master athlete, do not expect a single resistance training session to improve your mitochondrial health or biogenesis. While long-term resistance training is crucial for muscle mass and strength, acute mitochondrial remodeling (like building more mitochondria) is not triggered by a single bout of resistance exercise in these populations. Focus on consistency for muscle health, but rely on endurance training for acute mitochondrial signaling responses.

None of the tested dietary supplements (protein, creatine, HMB) significantly increased lean body mass in athletes when combined with strength and conditioning training.

Do not expect supplements like protein, creatine, or HMB to significantly increase your muscle mass on their own. Focus on your training and overall diet. This analysis found no significant benefit for muscle mass from these supplements in trained athletes.

Sleeve gastrectomy is associated with a higher risk of new-onset or worsening gastroesophageal reflux disease (GERD) compared to Roux-en-Y gastric bypass (RYGB).

If you have existing or severe acid reflux, Roux-en-Y gastric bypass is likely a safer choice than sleeve gastrectomy, as the sleeve procedure carries a higher risk of causing or worsening reflux.

Metabolic/bariatric surgery (MBS) is the most cost-effective intervention for class II and III obesity, often demonstrating dominance (cost-saving) over non-surgical management.

For individuals with Class II or III obesity, metabolic/bariatric surgery is the most economically and clinically effective long-term solution, often paying for itself through reduced healthcare costs from comorbidity remission. It should be prioritized over pharmacotherapy for this group.

Increases in lean mass (hypertrophy) are not significantly associated with improvements in muscle strength, endurance, or power in resistance-trained young males, indicating that functional adaptations occur independently of muscle size gains.

If you are a trained individual, do not assume that your strength gains are limited by your muscle size. You can improve your strength, power, and endurance significantly without necessarily gaining large amounts of lean mass. Focus on technical proficiency and neural adaptation (e.g., heavy loads, specific power drills) rather than just volume for hypertrophy, as these functional improvements can occur independently of muscle growth.

Improvements in cardiorespiratory fitness (VO2peak) do not consistently correlate with improvements in Metabolic Syndrome risk factors (blood pressure, lipids, glucose) following exercise training.

Do not assume that an increase in your maximum oxygen uptake (VO2peak) means your blood pressure or cholesterol has automatically improved. This study shows these two improvements are not consistently linked. You must monitor your specific risk factors (blood pressure, lipids, glucose) separately to assess the metabolic benefit of your exercise routine.

Obesity pharmacotherapy is recommended against for compounded medications or unapproved medications due to safety and efficacy concerns.

Avoid compounded weight loss medications. They are not approved, may be unsafe, and are not proven to work. Stick to FDA/Health Canada-approved medications prescribed by your doctor.

Initiation of modern antiretroviral therapy (ART), specifically integrase strand transfer inhibitors (INSTIs) like dolutegravir and bictegravir combined with tenofovir alafenamide (TAF), causes significant, sustained weight gain in people living with HIV, disproportionately affecting women and Black patients.

If you are living with HIV and starting or taking modern medication (specifically drugs ending in '-gravir' like dolutegravir or bictegravir, and TAF), expect significant weight gain, especially if you are a woman or Black. This is not just 'getting older' or 'eating too much'; it is a known side effect of the medication's interaction with your metabolism. Talk to your doctor about your risk factors. They may consider regimens with TDF (which mitigates weight gain) or other alternatives, though these may have other side effects. Be aware that standard diet and exercise might be less effective for this specific type of gain, and emerging weight-loss medications might be considered in the future.

Biomarker-based personalized nutrition plans do not result in greater weight loss or improvements in cardiometabolic health compared to a generic, generally healthy diet in individuals with overweight or obesity.

If you have overweight or obesity, following a generally healthy, balanced diet that provides enough food to satisfy you will result in similar weight loss and health improvements as following a highly personalized, biomarker-driven diet plan. You do not need to undergo expensive metabolic testing or follow complex personalized rules to achieve significant health benefits; consistency with a healthy, isocaloric diet is sufficient.

Chronic inflammation, oxidative stress, and gut dysbiosis form a reciprocal triad that perpetuates the pathophysiology of obesity.

Focus on reducing inflammation through diet (anti-inflammatory foods, fiber) and managing stress, as these factors directly impact gut health and oxidative stress, which in turn affect weight regulation.