Browse the evidence

Insulin resistance drives hepatic steatosis by disrupting normal insulin signaling, leading to unchecked de novo lipogenesis and increased free fatty acid flux from visceral adipose tissue.

Focus on improving insulin sensitivity through lifestyle changes, as insulin resistance is the primary driver of fat accumulation in the liver. This involves managing energy intake to reduce visceral fat and free fatty acid flux, and potentially reducing carbohydrate load to lower insulin levels, thereby allowing normal lipid metabolism to resume.

Progression from simple steatosis to steatohepatitis (NASH) is driven by a 'second hit' involving oxidative stress, inflammation, and mitochondrial dysfunction, often triggered by excess free fatty acids.

Preventing progression to NASH requires reducing the metabolic load on the liver. This involves minimizing factors that cause oxidative stress and inflammation, such as excessive alcohol intake (though NAFLD is non-alcoholic, alcohol adds stress) and high sugar/fructose intake which drives de novo lipogenesis.

Adipose tissue acts as an endocrine organ in obesity, secreting inflammatory cytokines (like TNF-alpha) and adipokines (like RBP4) that induce insulin resistance in the liver and muscle.

Weight loss reduces the mass of adipose tissue, thereby reducing the secretion of inflammatory cytokines and adipokines that drive insulin resistance. This improves the body's ability to manage blood sugar and reduces fat accumulation in the liver.

Combining Caffeine (5 mg/kg) and Ephedrine (1 mg/kg) does not produce an additive or synergistic effect on anaerobic performance compared to taking either substance alone.

Do not combine Caffeine and Ephedrine for anaerobic performance. You will not get a better result than taking Caffeine alone (for endurance) or Ephedrine alone (for early power). The combination adds side effects without adding performance benefits.

Acute exercise-heat-induced dehydration without fluid replacement increases sweat sodium and chloride concentrations in men, likely due to elevated extracellular fluid sodium, plasma aldosterone, and sympathetic nervous activity.

If you exercise for more than an hour in hot conditions, your sweat becomes saltier if you don't drink. This means you lose more sodium than you would if you stayed hydrated. To maintain performance and health, consider replacing fluids with electrolytes, especially sodium, rather than just plain water, to match the increased loss.

Blanket physical activity promotion via direct advice in primary care is ineffective at increasing self-reported physical activity compared to no intervention.

Do not rely on simple 'exercise more' advice in primary care settings as it is ineffective. Instead, use brief negotiation techniques that focus on the patient's own motivations and barriers.

Generalized Anxiety Disorder (GAD) is negatively associated with being overweight, meaning individuals with GAD are less likely to be overweight.

Generalized Anxiety Disorder is associated with a lower likelihood of being overweight. This may be due to the somatic symptoms of anxiety or excessive worry preventing overeating. However, this finding requires confirmation and should not be used to dismiss the health risks of anxiety.

Long-term consumption of dietary gluten is not associated with an increased risk of coronary heart disease in adults without celiac disease.

If you do not have celiac disease, there is no evidence that eating gluten harms your heart. In fact, avoiding gluten might lead you to eat fewer whole grains, which are good for your heart. You do not need to follow a gluten-free diet for cardiovascular health.

Obesity creates a pro-inflammatory environment in white adipose tissue that impairs signaling of fibroblast growth factor 21 (FGF21) by downregulating its co-receptor β-Klotho, leading to FGF21 resistance.

In obesity, the body's natural fat-burning signals (like FGF21) get blocked by inflammation. This means that simply having high levels of these hormones doesn't work; the fat cells stop listening. Reducing inflammation may be necessary to restore these fat-burning pathways.

Gastric bypass surgery reduces appetite and promotes long-term weight loss primarily through hormonal changes, specifically decreased ghrelin and increased PYY, rather than solely mechanical restriction.

Gastric bypass surgery works largely by changing your gut hormones: it lowers hunger signals (ghrelin) and boosts fullness signals (PYY). While surgery is a major step, you can try to mimic these hormonal effects through dietary choices that naturally stimulate these gut hormones, potentially helping with long-term weight management.

Leptin treatment is effective for weight loss only in individuals with congenital leptin deficiency, but offers limited benefit for the vast majority of obese people who have high circulating leptin.

Leptin is a hormone that signals fullness, but most obese people already have high levels of it. Taking leptin supplements does not help them lose weight. It is only effective for a very rare group of people with a specific genetic deficiency. For most, lifestyle changes remain the primary approach.

Central serotonergic signaling acts as an anorexigenic mechanism in the homeostatic circuitry by integrating metabolic signals to suppress food intake when energy needs are met, whereas peripheral serotonergic signaling promotes energy absorption and storage.

Your brain uses serotonin to decide when to stop eating. This process happens in specific brain areas that listen to your body's energy signals. If this system is disrupted, you might eat more than you need, contributing to weight gain. Understanding this helps explain why some medications affecting serotonin can impact weight.

Obesity is associated with disturbed serotonergic signaling, specifically decreased central serotonin release and altered receptor availability, which may contribute to the failure to suppress food intake.

In obesity, the brain's serotonin system often becomes less sensitive or releases less serotonin, making it harder to feel full. This biological change can drive overeating. Treatments that target this system (like certain drugs) may help restore this signaling.

Selective serotonin reuptake inhibitors (SSRIs) are associated with an increased risk of long-term weight gain, contrasting with their short-term anorexigenic effects.

If you take SSRIs, be aware they may contribute to weight gain over time. Talk to your doctor about monitoring your weight and discussing alternative treatments if this is a concern.

In healthy aging men, fat-free mass (primarily skeletal muscle) begins a non-linear decline around age 47, while fat mass increases until approximately age 70-80, resulting in a stable total body weight that masks significant body composition deterioration.

If you are a man over 40, do not rely on body weight or BMI to track your health. Your weight may stay the same while you lose muscle and gain fat. To maintain health, prioritize resistance training to preserve fat-free mass, as aerobic exercise alone was found to be insufficient to prevent this loss in this study.

Quantitative molecular and phenotypic biomarkers (e.g., DNA methylation, telomere length, physical function) can accurately measure physiological age and predict healthspan and lifespan.

Use available biomarkers (like blood tests or physical function metrics) to track your biological age rather than just your calendar age. This helps you assess your 'healthy aging' status and potentially predict your healthspan, allowing for earlier interventions to prevent age-associated diseases.

Integrating multiple biomarkers (molecular and phenotypic) using statistical or machine learning algorithms provides a more powerful prediction of physiological age than single biomarkers.

For the most accurate assessment of your biological age, use integrated panels that combine multiple blood tests and physical metrics, analyzed by advanced algorithms, rather than relying on a single test.

During the post-ovulatory luteal phase (LP) of the menstrual cycle, elevated progesterone levels increase core body temperature and reduce the nocturnal decline in body temperature, which contributes to subjective sleep disturbances and altered sleep architecture (specifically reduced REM sleep and increased spindle frequency activity) in healthy women.

If you are a healthy woman, expect your sleep architecture to change during the week before your period. You may experience less deep REM sleep and more sleep spindles due to a natural rise in body temperature driven by progesterone. This is a normal physiological shift, not a failure of your sleep hygiene. If you suffer from severe mood or sleep symptoms (PMDD), chronotherapeutic methods to realign circadian rhythms may help.

Elevated plasma acylcarnitine levels, particularly long-chain species, are biomarkers of insulin resistance and incomplete fatty acid oxidation in Type 2 Diabetes, reflecting mitochondrial stress rather than directly causing insulin resistance.

High levels of acylcarnitines in the blood are a sign of how your body is processing fats and sugars, indicating mitochondrial stress in T2D. This helps doctors understand the severity of metabolic dysfunction.

Nutrient deprivation (fasting or calorie restriction) increases SIRT6 protein levels in specific tissues (brain, kidney, heart, adipose) by stabilizing the protein via reduced proteasomal degradation, rather than by increasing transcription.

Fasting and calorie restriction do more than just burn calories; they actively stabilize specific proteins like SIRT6 in key organs (brain, heart, fat). This stabilization is a biological response to nutrient scarcity, potentially contributing to the health benefits associated with fasting, such as improved metabolic function and genome stability.

p53 positively regulates SIRT6 protein levels under normal growth conditions but is not required for the nutrient-dependent stabilization of SIRT6 during fasting.

Under normal eating conditions, the protein p53 helps maintain baseline levels of SIRT6. However, when you fast, your body uses a different mechanism to boost SIRT6 that doesn't rely on p53, suggesting multiple layers of protection.

Caloric restriction (CR) increases mitochondrial fission proteins and biogenesis to maintain ATP levels and reduce oxidative stress, contributing to longevity, whereas starvation induces mitochondrial fusion to protect against degradation.

Moderate caloric restriction may enhance mitochondrial health by increasing the number of mitochondria (biogenesis) and reducing oxidative stress, which are linked to longevity. This is distinct from severe starvation, which triggers fusion to protect existing mitochondria.

Testosterone supplementation reverses age-related sarcopenia in mice by suppressing processed myostatin and JNK activation while stimulating Akt and Notch signaling pathways.

For aging individuals experiencing muscle loss, testosterone therapy may be a viable option to restore muscle mass and strength, particularly when combined with lifestyle interventions. Consultation with a healthcare provider is essential to determine suitability and monitor for potential side effects.

Activation of the CML-RAGE axis in adipose tissue drives obesity-associated inflammation and insulin resistance by dysregulating adipokine expression (increasing pro-inflammatory cytokines and decreasing adiponectin).

This research suggests that obesity-related insulin resistance is driven by a specific molecular loop involving CML and RAGE in fat tissue. While this paper does not prescribe a direct intervention, it implies that reducing the formation of CML (an advanced glycation end product formed via lipid peroxidation) or blocking RAGE could theoretically improve insulin sensitivity. For now, strategies that reduce oxidative stress and lipid peroxidation (often associated with high sugar/fat diets) may indirectly mitigate this pathway.