Browse the evidence

Thyroid hormone substitution therapy in hypothyroid patients produces only modest weight loss (3-5 kg) and does not resolve obesity; therefore, obesity treatment should not be delayed until thyroid levels are normalized.

Do not wait for your thyroid levels to normalize before starting weight loss efforts. Thyroid medication will only help you lose a small amount of weight (3-5 kg). Focus on behavioral changes (diet and exercise) and other obesity treatments immediately, as these are the primary drivers of weight loss.

Higher total protein intake (up to ~116g/day) is not significantly associated with reduced risk of cardiovascular disease (CVD), coronary heart disease (CHD), or stroke in middle-aged adults.

If you are a middle-aged adult concerned about heart disease, simply eating more protein than you currently do is unlikely to lower your risk of heart attack or stroke. Focus on overall dietary patterns and established risk factors rather than just maximizing protein grams.

Higher diversity of protein sources (specifically 'count' of sources) is weakly associated with a marginally higher risk of CVD, while 'dissimilarity' of sources shows no association.

Don't assume that eating many different types of protein (e.g., chicken, beef, fish, beans, tofu) will protect your heart. This study suggests that having a high count of protein sources might be weakly linked to higher risk, possibly due to what those sources are (e.g., processed meats).

In patients with Obstructive Sleep Apnea (OSA) treated with CPAP, a history of prior vascular events, hypertension, older age at treatment initiation, and higher comorbidity burden are significant independent risk factors for subsequent vascular events, whereas obesity (BMI) is not.

If you have OSA and use CPAP, adherence is crucial, but it does not guarantee immunity from heart issues. Your risk of a vascular event is significantly higher if you have high blood pressure, a history of heart problems, or other chronic conditions. Focus on managing your blood pressure and comorbidities alongside your CPAP therapy, and seek early diagnosis and treatment to mitigate age-related risks.

Modern commercial Paleolithic diet variants (low-carb/high-fat) and extreme Carnivore diets contradict anthropological evidence of ancestral carbohydrate intake (35-72% of energy) and may increase cardiovascular risk by promoting high saturated fat intake and dyslipidemia.

If you are following a commercial Paleo or Carnivore diet, be aware that your macronutrient profile (very low carb, high saturated fat) differs significantly from what anthropological evidence suggests ancestral humans ate. Current scientific consensus links high saturated fat intake to elevated LDL and cardiovascular risk. While these diets may offer short-term benefits (possibly via elimination of processed foods or FODMAPs), long-term adherence to high saturated fat levels may increase cardiovascular risk. Consider aligning your diet with evidence-based guidelines that limit saturated fat, rather than relying on evolutionary arguments alone.

Vegan diets do not significantly affect blood pressure, HDL-C, or triglycerides compared to control diets in individuals with overweight or type 2 diabetes.

Do not expect a vegan diet to automatically lower your blood pressure or triglycerides if they are currently normal or if the diet is not carefully managed. The primary benefits observed were weight loss, improved HbA1c, and reduced LDL cholesterol. Monitor your BP and triglycerides separately.

Phentermine/Topiramate increases the risk of psychological side effects including depression, anxiety, sleep disorders, and irritability.

Avoid Phentermine/Topiramate if you have a history of psychiatric disorders, as it increases the risk of anxiety, sleep issues, and irritability. Other options like Tirzepatide or Semaglutide may be safer for mental health.

Time-restricted eating (TRE) does not significantly preserve lean body mass compared to control groups in adults with obesity.

Don't worry that TRE will cause you to lose muscle faster than a standard diet. The evidence shows lean mass loss is similar to control groups. Focus on protein intake and strength training to preserve muscle, as TRE itself doesn't offer a specific advantage in this regard.

Tirzepatide significantly increases the risk of gastrointestinal adverse events, including nausea, vomiting, and diarrhea, compared to placebo.

Be prepared for potential stomach issues like nausea, vomiting, and diarrhea when starting tirzepatide. These side effects are common and significantly more likely than with a placebo. Starting at a low dose and increasing slowly can help your body adjust. If side effects are severe, talk to your doctor about adjusting your dose or stopping the medication.

Time-restricted eating (TRE) significantly increases low-density lipoprotein (LDL) cholesterol levels in adults with overweight and obesity, although it does not significantly alter total cholesterol, HDL, or triglycerides.

While TRE helps reduce body fat, be aware that it may slightly increase your LDL ('bad') cholesterol. This increase was statistically significant but the authors note it does not pose a significant safety concern for most. If you have existing heart conditions or high cholesterol, monitor your levels and consult a doctor.

Twice-per-week intermittent fasting (5:2 diet) is not superior to continuous energy restriction for weight loss or insulin resistance in night shift workers, though it may offer specific lipid benefits.

For night shift workers, a 5:2 intermittent fasting plan (eating ~500 kcal on 2 non-consecutive days) is just as effective for weight loss as eating slightly less every day. It does not offer superior metabolic benefits like insulin sensitivity, but it may help lower LDL cholesterol. Choose the method that fits your schedule best, as adherence is key.

A 12-month 4:3 intermittent fasting protocol does not produce different changes in fasting appetite-related hormones (leptin, ghrelin, PYY, BDNF, adiponectin) compared to daily caloric restriction when energy deficits are matched.

Don't expect intermittent fasting to magically fix your hunger hormones differently than daily calorie counting. The benefit of 4:3 IMF comes from how it changes your eating behaviors and psychological relationship with food, not from a unique hormonal advantage.

A modest reduced-calorie diet does not significantly alter plasma levels of Brain-Derived Neurotrophic Factor (BDNF) or glycemic factors (glucose, insulin, HOMA-IR) in overweight/obese adults with cardiovascular risk factors over a two-month period.

While cutting calories helps your cholesterol and blood pressure, it might not immediately change your blood sugar levels or brain-derived neurotrophic factor (BDNF) levels in just two months. This doesn't mean the diet isn't working; it means these specific markers may take longer to respond or may not respond in everyone, especially if you are already on medication. Focus on the improvements you can see, like weight and lipid profiles.

Time-restricted eating (TRE) does not significantly improve BMI, fat mass, blood lipids, glucose, or blood pressure in overweight and obese women compared to control groups.

Do not expect TRE to automatically fix your BMI or cholesterol levels if you do not also manage your total calorie intake. While it helps with weight and insulin, it does not significantly alter fat mass or blood pressure on its own in this population.

Combining Time-Restricted Eating (TRE) with Energy Restriction (ER) provides no additional benefit for weight loss or fat mass reduction compared to TRE alone.

If you are already practicing Time-Restricted Eating, you do not need to add explicit calorie counting or energy restriction to achieve weight loss. TRE alone is sufficient for significant fat and weight reduction. Adding calorie restriction does not provide extra benefits for weight loss in this context.

Butyrate maintains anaerobic conditions in the colon by activating PPARγ and repressing inducible nitric oxide synthase (iNOS), which prevents the proliferation of pathogenic facultative anaerobes like Enterobacteriaceae.

Maintain a healthy gut barrier by ensuring adequate butyrate production. Butyrate, a short-chain fatty acid produced by bacteria from fiber, activates PPARγ in colon cells to limit oxygen diffusion and repress inflammatory enzymes (iNOS). This creates an anaerobic environment that suppresses pathogenic bacteria like Enterobacteriaceae. Prioritize dietary fibers that promote butyrate production, such as resistant starches.

Metabolic endotoxaemia, characterized by elevated circulating lipopolysaccharides (LPS) due to increased gut permeability, drives low-grade chronic inflammation associated with type 2 diabetes, NAFLD, and obesity.

High-fat diets can increase gut permeability, allowing lipopolysaccharides (LPS) from Gram-negative bacteria to enter the bloodstream. This triggers a low-grade inflammatory response via Toll-like receptors, contributing to insulin resistance and metabolic diseases like type 2 diabetes and NAFLD. Managing fat intake and supporting gut barrier integrity are key to reducing this inflammatory burden.

Caloric restriction (CR) is an effective intervention that impacts aging, age-related pathologies, and longevity in model organisms such as mice and rats.

While this paper confirms caloric restriction extends longevity in mice and rats, it does not provide specific human dosing protocols. For humans, this suggests that avoiding overconsumption and maintaining a healthy weight may support healthy aging, but specific restriction protocols should be discussed with a healthcare provider.

Epigenetic clocks, such as the DNAm PhenoAge and DunedinPoAm, can predict biological age, lifespan, and risk of chronic disease.

Epigenetic clocks are emerging tools to measure biological aging. While not yet standard clinical practice, they may eventually help individuals track the impact of lifestyle changes on their biological age.

Specific gut microbiota species and their metabolites (SCFAs, bile acids) actively maintain intestinal barrier integrity and exert anti-inflammatory effects.

Consuming a diet rich in diverse fibers supports the growth of beneficial bacteria that produce SCFAs and strengthen the gut barrier. This is a key strategy for reducing systemic inflammation and supporting metabolic health.

High-fat diets and saturated fatty acids can disrupt intestinal barrier integrity and promote systemic inflammation via TLR4 activation and bile acid alterations.

Limiting saturated fat intake and focusing on unsaturated fats can help maintain gut barrier integrity and reduce systemic inflammation, especially in individuals prone to metabolic issues.

The SenMayo gene set (125 genes) accurately identifies senescent cells across tissues and species, and its expression levels significantly decrease following genetic or pharmacological clearance of senescent cells, serving as a reliable biomarker for senolytic efficacy.

SenMayo is a validated 125-gene signature that can detect senescent cells in various tissues (bone, brain, fat) and track their reduction after senolytic treatments (like Dasatinib + Quercetin). It is currently a research tool for monitoring senolytic efficacy, not a standard clinical test yet.

The AGEs/RAGE axis contributes to pancreatic beta cell toxicity and apoptosis via oxidative stress and islet amyloid polypeptide (IAPP) aggregation.

Preserving beta cell function is crucial; strategies that reduce AGEs and oxidative stress may help protect pancreatic beta cells.

Epigenetic clocks based on DNA methylation levels can predict chronological age and the risk of aging-related diseases.

Epigenetic clocks can measure biological age. This can help assess the efficacy of aging interventions.