Browse the evidence

In healthy humans, disuse-induced muscle atrophy is primarily driven by a significant reduction in muscle protein synthesis (MPS), while muscle protein breakdown (MPB) remains largely unchanged.

If you are immobilized or inactive but healthy, your muscle loss is not because your body is actively destroying muscle tissue, but because it has stopped building it. The primary lever to prevent loss is to restore the stimulus for muscle protein synthesis (e.g., through resistance exercise or adequate protein intake) rather than focusing solely on preventing breakdown.

In disease states (e.g., sepsis, cancer, critical illness), muscle atrophy is driven by both elevated muscle protein breakdown (MPB) and reduced muscle protein synthesis (MPS), mediated by inflammatory cytokines.

If you have a disease involving inflammation (like cancer or sepsis), your muscle loss is driven by both increased breakdown and decreased synthesis due to inflammatory signals. Preventing loss requires addressing the underlying disease and inflammation, not just rest or exercise.

Intense cycling exercise activates MAPK (ERK1/2, p38) and AMPK signaling pathways in skeletal muscle, leading to downstream phosphorylation of MSK1 and histone H3, with untrained individuals exhibiting a greater signaling response than highly trained athletes at the same relative intensity.

If you are a trained athlete, standard moderate-intensity exercise may not trigger the same level of cellular signaling (MAPK/AMPK) as it does for beginners. To maintain these specific adaptive signals, you likely need to increase the intensity or volume of your training, as your muscles have adapted to be more resistant to these stimuli.

In overweight or obese individuals with type 2 diabetes, metabolic dyslipidemia (defined as high triglycerides and low HDL-C) is associated with a significantly higher risk of coronary artery disease and composite cardiovascular events, independent of LDL-C levels.

If you have Type 2 Diabetes and are overweight, your risk of heart disease is significantly higher if you have both high triglycerides and low HDL cholesterol, even if your LDL is normal. This risk exists independently of your LDL levels. You should discuss your triglyceride and HDL levels with your doctor as part of your cardiovascular risk assessment, not just your LDL.

Endurance exercise, but not resistance exercise, significantly enhances the phosphorylation of proteins responsible for glucose transport (AS160) and glycogen synthesis (Glycogen Synthase) during the early recovery period.

If you are trying to improve how your muscles handle glucose or replenish glycogen stores after a workout, endurance exercise is the more effective stimulus in the immediate recovery period. Resistance training, while great for muscle structure, does not trigger these specific glucose-handling signals as strongly in the first hour.

Spontaneous long-term weight gain triggers a metabolic adaptation where increases in 24-hour energy expenditure and fat oxidation are overcompensatory (greater than predicted by changes in body composition), acting to oppose further weight gain.

Your body does try to defend its weight when you gain it, by burning slightly more calories and fat. However, this defense is very weak—roughly equivalent to the calories in half an apple. This means that while your body is trying to help, it is easily overwhelmed by small increases in food intake. Understanding this helps explain why weight gain is easy to sustain and why willpower alone is difficult; the biological 'brakes' are weak.

Linoleic acid has a long half-life in the body (approximately two years), meaning that reducing intake takes years to significantly lower tissue levels.

Be patient when reducing seed oils. It can take up to six years to significantly replace body stores of linoleic acid with healthier fats.

Nutritional stunting (chronic early-life undernutrition) causes long-term physiological adaptations—including lower resting energy expenditure, reduced fat oxidation, and impaired food intake regulation—that increase susceptibility to obesity when caloric intake increases.

If you were stunted as a child, your body may be biologically programmed to store fat more efficiently and burn less energy than someone who was well-nourished. Standard 'eat less, move more' advice may be less effective because your metabolic rate and fat oxidation are lower. Focus on nutrient-dense foods and strength training to preserve muscle mass, rather than severe caloric restriction, which your body may resist more strongly.

In young healthy men, larger baseline subcutaneous adipocyte size protects against overfeeding-induced insulin resistance and ectopic lipid accumulation, whereas smaller adipocytes are associated with worsened metabolic outcomes despite similar weight gain.

If you have larger subcutaneous fat cells, you may be metabolically protected against the negative effects of occasional overeating compared to someone with smaller cells. However, this does not mean overeating is safe; it still causes weight gain and some metabolic stress. Focus on long-term health rather than trying to 'shrink' fat cells, as smaller cells may actually predispose you to insulin resistance during periods of excess energy intake.

FAO food balance sheet estimates of national per capita food supply substantially overestimate actual individual-level dietary intakes for most food groups (e.g., by 74.5% for vegetables and 270% for whole grains) and underestimate others (e.g., by 250% for beans/legumes), rendering raw FAO data invalid for assessing individual dietary quality or diet-disease relations without calibration.

Do not use UN FAO food balance sheets to judge how much people actually eat. These numbers are systematically wrong, often overstating consumption by 50-270% for foods like vegetables and grains. If you must use FAO data for global comparisons, you must apply specific calibration equations that account for country, age, sex, and region to correct for this bias.

Dietary diversity measures (count, evenness, dissimilarity) are not standardized and do not consistently correlate with diet quality scores like HEI or DASH.

Do not rely on 'dietary diversity scores' to judge your diet's health. These scores are not standardized and often do not reflect actual diet quality. Focus on specific food groups (vegetables, fruits, whole grains) rather than the number of different foods you eat.

Higher circulating levels of total long-chain omega-3 polyunsaturated fatty acids (n-3 PUFAs) and specifically docosahexaenoic acid (DHA) are associated with a significantly lower risk of incident atrial fibrillation in older adults.

For older adults, maintaining higher blood levels of long-chain omega-3s (specifically DHA and total n-3 PUFAs) is linked to a lower risk of developing atrial fibrillation. This association was observed in people not taking fish oil supplements, suggesting that dietary intake of fatty fish (which raises these biomarkers) may be protective. While this study does not prove causation, it supports guidelines recommending regular consumption of fatty fish for cardiovascular health.

Very low-carbohydrate/ketogenic, Paleolithic, and low-carbohydrate dietary patterns have low to moderate or poor alignment with 2021 AHA Dietary Guidance due to restrictions on whole grains, legumes, and oils, and high saturated fat content.

If you follow a low-carb, Paleo, or ketogenic diet, be aware that it may not align well with heart health guidelines. These diets often restrict whole grains, legumes, and healthy oils, and may be high in saturated fat. Consult a registered dietitian to ensure nutrient adequacy and minimize cardiovascular risk.

In Pima Indians, increased adiposity and hyperinsulinemia do not trigger the sympathetic nervous system (SNS) activation typically seen in whites, which contributes to a lower prevalence of hypertension despite high obesity rates.

This research suggests that the link between obesity and high blood pressure is not universal. For some populations (like Pima Indians), high body fat and insulin levels do not trigger the stress response (SNS) that usually raises blood pressure. This highlights that genetic background plays a critical role in how the body handles weight and stress.

In White males, increased body fat and hyperinsulinemia are positively associated with increased muscle sympathetic nerve activity (MSNA), which in turn is associated with higher blood pressure.

For White males, losing weight and managing insulin levels may help lower blood pressure by reducing sympathetic nervous system activity. This study confirms that in this group, higher body fat and insulin lead to higher stress signals (MSNA) and higher BP.

Higher BMI (specifically >40 kg/m2) is associated with a significantly increased risk of severe vision loss and more severe papilledema in IIH patients.

If you have IIH, maintaining a lower BMI is crucial to protect your vision. A BMI over 40 kg/m2 significantly increases your risk of severe vision loss. Prioritize weight management to mitigate this risk.

Ownership of both a car and a television is associated with an increased risk of myocardial infarction, serving as a marker of a sedentary lifestyle.

Be aware that owning both a car and a TV is statistically linked to higher heart attack risk. This doesn't mean you must sell them, but it signals a higher risk profile. Counteract this by ensuring you engage in regular leisure-time physical activity to offset the sedentary tendencies these goods may encourage.

During refeeding after semistarvation, elevated de novo lipogenesis (DNL) combined with increased fat intake causes a rapid overshoot of body fat mass, which takes more than one year to return to baseline levels even with original diet and activity.

After a period of significant weight loss or starvation, your body will likely store fat rapidly when you start eating normally again. This is driven by increased fat synthesis (DNL) and high fat intake. Don't panic; this overshoot is not permanent. If you return to your pre-starvation diet and activity levels, your body fat will eventually return to baseline, but expect it to take over a year, not weeks.

Non-optimal systolic blood pressure (SBP) is the leading metabolic risk factor for cardiometabolic mortality in the MENA region, causing 48% of deaths.

Monitor and manage blood pressure aggressively, as it is the number one metabolic driver of heart disease and diabetes deaths in the MENA region. Target levels below 115 mm Hg for optimal protection.

Ultraprocessed food (UPF) consumption does not have a unique mechanistic link to increased body mass index or obesity risk, as epidemiological associations are weak and mechanistic evidence is lacking or contradictory.

Do not avoid all processed foods based on the NOVA classification. Focus on nutrient density, portion control, and overall dietary patterns. Many processed foods are safe, nutritious, and affordable. Avoiding them entirely may lead to nutrient deficiencies and higher costs without proven health benefits.

In healthy young men, overfeeding by ~1,000 kcal/day for 21 days does not trigger a significant adaptive increase in energy expenditure (other than obligatory thermic effect), resulting in 85-90% of excess energy being stored as fat and protein.

If you are a healthy young man, eating 1,000 extra calories a day for three weeks will not significantly boost your metabolism to burn off those calories. Instead, your body will store about 85-90% of that excess energy as fat and protein. You might naturally eat less later, but during the overfeeding period, you will gain weight because your energy expenditure does not increase enough to match the intake.

Matching the total energy expenditure of exercise bouts reveals that high-intensity aerobic exercise does not result in greater 24-hour energy expenditure or fat oxidation compared to low-intensity exercise.

If your goal is fat loss, focus on the total calories you burn, not just the intensity. This study shows that doing 400 calories of low-intensity cycling burns just as much fat over 24 hours as doing 400 calories of high-intensity cycling. You can choose the intensity that you can sustain consistently without injury or burnout. High intensity is not 'better' for fat oxidation if the total work is the same.

Bariatric surgery significantly reduces the overall incidence of cancer, obesity-related cancers, and cancer-associated mortality in patients with morbid obesity compared to conventional treatment.

For individuals with morbid obesity, bariatric surgery is a highly effective intervention for reducing the risk of developing various cancers, particularly obesity-related types like breast, colorectal, and endometrial cancer, as well as reducing cancer mortality. This benefit is attributed to sustained weight loss and metabolic improvements that are difficult to achieve through lifestyle changes alone.

Bariatric surgery significantly reduces the incidence of specific obesity-related cancers, including hepatocellular, colorectal, pancreatic, gallbladder, breast, endometrial, and ovarian cancers.

Bariatric surgery offers significant protection against several specific types of cancer, particularly those linked to obesity and hormones (breast, endometrial, ovarian) and metabolic factors (liver, colorectal, pancreatic, gallbladder).