Browse the evidence

Genetic factors significantly predispose individuals to obesity, with heritability estimates exceeding 70% for fat difference, involving genes like LEP, LEPR, and MC4R.

If you have a family history of obesity, be aware that your body may fight weight loss more strongly. Focus on consistent, sustainable habits rather than quick fixes, and consider seeking professional guidance to navigate biological challenges.

For individuals with obesity and prediabetes who fail to achieve early weight loss (<2.5% at 4 weeks), adding exercise counseling or time-restricted eating (TRE) counseling does not significantly improve weight loss or glycemic outcomes compared to continuing the initial diet alone.

If you are not losing weight in the first month of a diet, simply adding more exercise counseling or trying a new eating window might not be enough. You may need more intensive support, such as provided meals or supervised exercise, rather than just advice.

Administration of the plasma protein encoded by the obese gene (leptin) reduces body weight in genetically obese (ob/ob) mice by restoring energy balance.

This foundational research identifies leptin as a key hormone regulating body weight. For individuals with specific genetic leptin deficiencies, leptin therapy can be effective. For the general population, this highlights the importance of hormonal balance in weight management, though direct leptin supplementation is not a standard or effective treatment for common obesity due to leptin resistance.

Obesity induces chronic low-grade inflammation in adipose tissue, which impairs insulin signaling and leads to insulin resistance.

Excess body fat, especially around the midsection (visceral fat), is not just inert storage; it actively releases inflammatory chemicals that block your body's ability to use insulin. This biological change is a primary driver of metabolic disease, meaning that managing inflammation and fat distribution is as critical as calorie counting for metabolic health.

Macrophage infiltration into adipose tissue is a primary mechanism by which obesity causes insulin resistance.

Reducing the accumulation of immune cells (macrophages) in fat tissue may improve insulin sensitivity. This suggests that anti-inflammatory strategies could be beneficial for metabolic health in obesity.

Senescent cells secrete a complex, heterogeneous proteome (SASP) that includes specific proteins (GDF15, STC1, SERPINs) which correlate with human aging and serve as potential plasma biomarkers for cellular senescence burden.

This research identifies specific proteins (GDF15, STC1, SERPINs) secreted by senescent cells that correlate with aging in human blood. While not yet a commercial test, these markers offer a potential way to measure 'senescent burden' in the future, linking cellular aging to systemic health.

Supplementation with Vitamin E and Ascorbic Acid (Vitamin C) does not significantly reduce the risk of coronary heart disease, and may have adverse effects in some trials.

Do not rely on Vitamin E or Vitamin C supplements to prevent heart disease, as evidence shows they are not significantly associated with reduced risk and may have adverse effects in some trials.

Current evidence does not clearly support cardiovascular guidelines that encourage high consumption of polyunsaturated fatty acids (omega-3 and omega-6) or low consumption of total saturated fats for coronary risk reduction.

Current evidence does not strongly support the specific guideline advice to drastically increase polyunsaturated fat intake or strictly limit total saturated fat for the purpose of preventing coronary disease. While trans fats should still be avoided, the distinction between saturated and unsaturated fats may be less critical for heart health than previously believed, according to this large meta-analysis.

Supplementation with long-chain omega-3 and omega-6 polyunsaturated fatty acids does not statistically significantly reduce the risk of coronary outcomes in randomized controlled trials.

Taking omega-3 supplements (0.3-6g/day) does not appear to significantly reduce the risk of coronary disease based on this large review of randomized trials. While some observational studies suggested benefits, the higher-quality trial data did not confirm a significant protective effect.

Peripheral administration of the GLP-1 receptor agonist liraglutide induces weight loss primarily by crossing the blood-brain barrier to activate GLP-1 receptors on POMC/CART neurons in the arcuate nucleus (ARC), rather than via vagal or area postrema pathways.

Liraglutide reduces body weight by entering the brain and activating specific neurons (POMC/CART) in the arcuate nucleus that regulate appetite. This central action is the primary driver of weight loss, distinct from peripheral effects like slowed stomach emptying. The drug requires crossing the blood-brain barrier to bind to GLP-1 receptors on these specific neurons.

Grip strength is not significantly associated with prostate cancer mortality, although it is associated with the incidence of prostate cancer.

For men, low grip strength does not predict death from prostate cancer. However, it is associated with a higher *incidence* of prostate cancer, possibly because stronger men are more health-conscious and get screened more often. Do not use grip strength to rule out prostate cancer risk.

High intake of saturated fat and cholesterol is associated with increased risk of fatal coronary heart disease, but this association is largely explained by low dietary fiber intake rather than the fats themselves.

For heart health, prioritize increasing your intake of dietary fiber from whole plant foods (cereals, vegetables, fruit) over simply cutting fat. While high saturated fat intake was linked to fatal heart disease in this study, the risk was significantly reduced when fiber intake was accounted for, suggesting fiber plays a crucial protective role.

There is insufficient evidence to recommend low-carbohydrate diets for use longer than 90 days, for participants older than 50 years, or for diets providing 20 g/d or less of carbohydrates.

If you are over 50 or plan to follow a very low-carb diet (<20g) for more than 3 months, be aware that current scientific evidence is insufficient to confirm its safety or efficacy. Consult a healthcare provider before committing to these specific parameters.

In heart failure, the failing heart shifts from efficient fatty acid oxidation to inefficient glycolysis, leading to acidosis, ion overload, and reduced ATP production, which exacerbates cardiac dysfunction.

In heart failure, the heart's energy system breaks down, relying on inefficient processes that create toxic byproducts (acidosis) and reduce power (ATP). This metabolic shift worsens the heart's ability to pump. Treatments targeting this metabolic inflexibility (like ketone bodies or specific drugs) may help, but the core issue is the heart's inability to efficiently burn fuel.

Insulin resistance is a primary driver of cardiovascular risk in obesity, whereas obesity itself (without insulin resistance) does not significantly increase mortality or cardiovascular risk.

Having excess body fat does not automatically mean you have a high risk of heart disease or early death. The critical factor is insulin resistance. If you are obese but metabolically healthy (normal insulin sensitivity), your cardiovascular risk may not be significantly elevated. Focus on improving metabolic health through activity and diet rather than just weight loss.

Adapting to a ketogenic low carbohydrate, high fat (LCHF) diet during intensified training impairs exercise economy and negates performance improvements in elite endurance athletes, despite increasing peak aerobic capacity.

For elite endurance athletes, switching to a strict ketogenic diet during intense training blocks is likely counterproductive. While it may increase your ability to burn fat, it appears to make your body less efficient at using oxygen at race speeds, leading to no performance gain despite improved aerobic capacity. Stick to high-carbohydrate or periodized carbohydrate strategies for performance outcomes.

The 'no-dipper' blood pressure pattern (lack of nocturnal BP reduction) is independently associated with higher cardiovascular risk and organ damage, regardless of standard Framingham risk scores or confirmed hypertension diagnosis.

If you have high blood pressure or cardiovascular risk, standard office checks might not tell the whole story. Ask your doctor about 24-hour ambulatory blood pressure monitoring (ABPM). This test checks if your blood pressure drops at night (dipping). If it doesn't (no-dipper), your risk of heart attack, stroke, and kidney damage is higher, even if your daytime readings look okay. Managing this pattern may require specific timing of medications (chronotherapy) or lifestyle changes to restore normal nighttime drops.

Intake of total fat, saturated fatty acids (SFA), monounsaturated fatty acids (MUFA), and polyunsaturated fatty acids (PUFA) is not associated with the risk of cardiovascular disease.

Current evidence from this meta-analysis does not support limiting total fat, saturated fat, or monounsaturated fat intake to prevent CVD, as no association was found. Focus on avoiding trans fats instead.

SGLT2 inhibitors (canagliflozin, dapagliflozin, empagliflozin) improve glycemic control in type 2 diabetes by blocking glucose reabsorption in the renal proximal tubule, inducing glycosuria.

If you have Type 2 Diabetes and your kidneys are functioning adequately (eGFR > 30), SGLT2 inhibitors like empagliflozin or dapagliflozin can help lower your blood sugar by causing your kidneys to excrete glucose in your urine. This is done via a daily oral pill. While there is a risk of genital infections, they are generally mild and manageable. The key benefit is that these drugs also offer cardiovascular and renal protection beyond just lowering blood sugar.

Once-weekly subcutaneous dulaglutide (1.5 mg) is administered to patients with type 2 diabetes to evaluate its effect on cardiovascular outcomes, including cardiovascular death, non-fatal myocardial infarction, and non-fatal stroke.

This paper outlines the design of the REWIND trial, which tests whether once-weekly dulaglutide (1.5 mg) reduces cardiovascular events (heart attack, stroke, cardiovascular death) in people with type 2 diabetes who are at high risk. The trial includes nearly 10,000 participants with a mean age of 66, many of whom have prior cardiovascular disease or risk factors. The results of this trial will help determine if dulaglutide is an effective cardiovascular protective agent for this population.

Consumption of fried fish or fish sandwiches (more than once per week) is associated with a 44% higher risk of ischemic stroke in elderly individuals compared to consuming less than once per month.

For elderly adults, eating fried fish or fish sandwiches more than once a week is linked to a significantly higher risk of ischemic stroke. To minimize this risk, avoid fried fish preparations and opt for baked or broiled fish instead.

Long sleep duration (>8 hours) in older adults is associated with increased mortality, but this risk is primarily explained by underlying health conditions and lifestyle factors rather than inflammation.

If you are an older adult sleeping more than 8 hours, your mortality risk is higher, but this is likely due to underlying health conditions or lifestyle factors rather than the sleep itself. Focus on managing chronic diseases and maintaining a healthy lifestyle rather than restricting sleep.

Intramuscular androgen receptor content, rather than systemic or intramuscular hormone levels, determines the magnitude of resistance training-induced skeletal muscle hypertrophy in healthy, young men.

If you are a healthy, young man who already lifts weights regularly, your muscle growth potential is likely determined by your genetic muscle receptor density, not your blood testosterone levels. You cannot change your receptor density with supplements or TRT if your levels are already normal. Focus on consistent, progressive resistance training rather than trying to manipulate hormones.

Obesity pathophysiology is driven by complex interactions between genetic susceptibility, environmental factors, and hormonal signaling (leptin, insulin, ghrelin, GLP-1) that regulate energy balance, rather than simple caloric imbalance alone.

Obesity is not just a failure of willpower; it involves complex hormonal signals (like leptin and insulin) and genetics. Effective management often requires addressing these biological drivers, potentially through lifestyle changes combined with medical therapies that target these specific pathways.