Browse the evidence

Short-term withdrawal (2-4 days) from caffeine restores the plasma norepinephrine response to acute caffeine ingestion during exercise, which is blunted in habitual users without withdrawal.

For habitual caffeine users, stopping caffeine for 2-4 days before an event will trigger a stronger norepinephrine spike when you take caffeine, compared to taking it while still consuming your normal amount. However, this hormonal spike does not appear to improve performance (endurance) compared to taking caffeine without withdrawal.

In chronically endurance-trained older adults, maximal oxygen uptake (VO2max) per kilogram of appendicular muscle mass is significantly reduced compared to younger counterparts, independent of age-associated changes in body composition (such as increased body fat or loss of muscle mass).

If you are an older endurance athlete, your cardiovascular system's ability to deliver oxygen to your muscles declines with age, regardless of how much you train. This is a physiological limit, not a failure of your training. Focus on maintaining your training volume and intensity to preserve muscle quality and oxidative capacity, as these adaptations are well-maintained in older subjects.

High-fat diets increase circulating lipopolysaccharide (LPS) levels ('metabolic endotoxemia'), which triggers systemic inflammation and insulin resistance via the TLR4 pathway.

High-fat meals can increase gut-derived toxins (LPS) in the blood, triggering inflammation that worsens insulin resistance. Reducing dietary fat, particularly saturated fats, may help lower this inflammatory burden.

Androgen deprivation therapy (ADT) for prostate cancer causes significant metabolic complications, including insulin resistance, hyperglycemia, and metabolic syndrome, which accelerate cardiovascular mortality.

If you are undergoing Androgen Deprivation Therapy for prostate cancer, you are at a significantly higher risk for developing diabetes, high cholesterol, and heart disease. You must undergo regular screening for blood sugar and lipids. Aggressively manage your weight, diet, and exercise to counteract the muscle loss and fat gain caused by the therapy. Discuss cardiovascular risk with your doctor before starting treatment.

Directive front-of-pack warning labels (e.g., Chilean stop-sign style) significantly improve consumers' ability to quickly identify products with high levels of key nutrients (sodium, sugar, saturated fat, energy) compared to non-directive (GDA) and semi-directive (traffic-light) systems.

When choosing between products, look for packages with black warning labels (like the Chilean system). These labels are designed to grab your attention faster than traffic lights or numbers, helping you quickly spot items high in sugar, salt, or fat. Use this visual cue to avoid products with high levels of these nutrients.

Warning labels significantly lower the perceived healthfulness and recommended consumption frequency of products high in energy, saturated fat, sugar, and sodium compared to GDA and traffic-light systems.

If you see a black warning label on a product, understand that it is a strong signal that the product is unhealthy. These labels are designed to make you think twice about how often you should eat it. Use this perception to limit your consumption of such items.

Warning labels and traffic-light systems are equally effective in helping consumers identify the most healthful product among a set of options, outperforming the GDA system.

When comparing products, look for warning labels or traffic-light systems. Both help you quickly spot the healthiest option, whereas GDA labels (numbers/percentages) are harder to use for comparison. Choose the product with the fewest warnings or the most green lights.

Surgical weight loss leads to significant psychosocial improvements, including enhanced body image, self-esteem, marital satisfaction, and vocational functioning, often reversing pre-existing psychological disturbances.

Beyond weight loss, surgery often brings profound psychological benefits, including improved self-esteem, better body image, and stronger social and marital relationships. Many patients report feeling more confident, engaging more in social activities, and experiencing less discrimination after surgery.

The mortality risk associated with low-carbohydrate and low-fat diets depends entirely on the quality of macronutrients consumed; diets emphasizing refined carbohydrates, saturated fats, and animal proteins increase mortality, whereas diets emphasizing whole grains, unsaturated fats, and plant proteins decrease mortality.

Do not follow a generic 'low-carb' or 'low-fat' plan if your goal is longevity. Instead, ensure your carbohydrate sources are whole grains and vegetables, and your fats are unsaturated (plant oils, nuts, fish). Avoid refined sugars, refined grains, and saturated animal fats. The quality of your macros matters more than the total percentage.

When training volume is NOT equated, higher training frequencies (3+ days/week) may lead to greater hypertrophy than lower frequencies (1-2 days/week), but the effect size is modest.

If you are not carefully tracking and matching your weekly sets, training a muscle group more frequently might naturally lead to higher total volume and thus more growth. However, this benefit is modest and likely just a byproduct of doing more work, not the frequency itself.

Hormonal Replacement Therapy (HRT) reduces visceral fat mass and improves insulin sensitivity in postmenopausal women, particularly when initiated during perimenopause or early menopause.

If you are going through menopause and concerned about weight gain, talk to your doctor about Hormonal Replacement Therapy (HRT). Starting HRT early (during perimenopause or shortly after menopause) can help reduce belly fat and improve how your body handles sugar. However, this should be combined with a healthy diet and exercise, and only done if your doctor determines it is safe for you.

The protective association between dietary fiber and metabolic syndrome is supported by mechanisms involving energy dilution, appetite suppression, and gut microbiota modulation.

Understanding how fiber works can help adherence: it fills you up (appetite suppression), dilutes calories (energy dilution), and feeds good gut bacteria (microbiota). These combined effects help manage weight and blood sugar, key components of metabolic syndrome.

Growth hormone (GH) administration during caloric restriction preserves lean body mass (nitrogen retention) for approximately 5 weeks, after which the anabolic effect is lost despite continued GH treatment.

If you are using Growth Hormone to preserve muscle while dieting, expect it to work for about 5 weeks. After that, the muscle-saving benefit disappears even if you keep taking it. It does not accelerate fat loss, so the risk/cost ratio worsens over time. Do not rely on it for long-term body composition changes.

Combining two specific night eating habits—dinner within 2 hours of bedtime and snacks after dinner (each occurring ≥3 times/week)—significantly increases the odds of developing obesity (BMI ≥25 kg/m²) and dyslipidemia in both men and women, with a supra-additive interaction effect observed in women.

If you frequently eat dinner within 2 hours of bed and snack after dinner (3+ times a week), you are at a significantly higher risk for obesity and high cholesterol, especially if you are a woman. To mitigate this, try to finish your last meal earlier in the evening and avoid late-night snacking. This is particularly important for women, where the combination of these habits showed a synergistic negative effect.

Vigorous late-night exercise (ending ~2 hours before bedtime) does not disturb polysomnographic, actigraphic, or subjective sleep quality in healthy, physically fit young adults, despite causing elevated heart rate during the first three hours of sleep.

If you are young and physically fit, doing a hard workout late at night (ending about 2 hours before bed) will not ruin your sleep. You might wake up with a higher heart rate initially, but you will still fall asleep easily and get good restorative sleep. You do not need to stop exercising late just because of sleep concerns.

COVID-19 lockdown measures significantly worsened sleep quality in nursing students, primarily through increased sleep latency and reduced sleep efficiency, despite an increase in total time spent in bed.

If you are struggling with sleep during periods of restricted routine (like lockdowns or remote work), do not assume that staying in bed longer will help. The study shows that sleep quality often worsens despite increased time in bed due to delayed bedtimes and increased pre-sleep screen use. Focus on maintaining a consistent sleep-wake schedule and limiting digital device use before bed to improve sleep efficiency.

Specific demographic and lifestyle factors, including female gender, younger year of study (1st/2nd year), alcohol consumption, and living with family, are associated with greater sleep quality deterioration during lockdown.

If you are a female nursing student, in your first or second year, drink alcohol, or live with family, be aware that lockdown or routine changes may disproportionately impact your sleep. Monitor your sleep hygiene closely, particularly regarding alcohol consumption and pre-sleep routines, as these factors may exacerbate sleep quality issues during stressful periods.

Processing methods such as germination, boiling, and autoclaving significantly reduce antinutrients (phytates, oxalates, tannins) and improve protein digestibility in amaranth grain.

To get the most nutrition from amaranth, process it before eating. Germinate the grains at 30°C for 72 hours to boost protein digestibility, or boil/autoclave them to reduce antinutrients like phytates and oxalates. This makes the minerals and protein more available to your body.

Smaller thigh circumference is independently associated with increased risk of cardiovascular disease and premature death, with a critical threshold effect below approximately 60 cm.

Measure your thigh circumference. If it is below 60 cm (for women) or 62 cm (for men), you may have an elevated risk for heart disease and premature death, independent of your weight or waist size. This likely reflects lower muscle mass in the legs. Focus on resistance training to build or maintain leg muscle mass, rather than just cardio or weight loss, to potentially mitigate this risk. Consult a doctor for personalized advice, as this is a screening marker, not a diagnosis.

Multi-frequency bioelectrical impedance analysis (MF-BIA) using an age-independent equation (incorporating impedance ratios and 1/Z50) accurately estimates appendicular skeletal muscle mass (ALM) comparable to DXA, whereas traditional age-dependent BIA equations significantly underestimate ALM in younger adults.

If you are tracking muscle mass changes, especially if you are young or comparing yourself to older data, standard consumer BIA scales may be misleading because they often use age-dependent formulas that underestimate muscle in younger people. For accurate research or clinical assessment, use a validated, age-independent MF-BIA equation or DXA. For general fitness, focus on strength and performance metrics rather than the absolute number from a consumer scale.

Sarcopenia cutoff values for appendicular lean mass index (ALM/Ht2) can be established using MF-BIA with a disclosed, age-independent equation, yielding values (6.8 kg/m2 for men, 5.7 kg/m2 for women) similar to those derived from DXA.

For clinical screening of sarcopenia in Japanese adults, MF-BIA can be used to identify at-risk individuals using cutoffs of 6.8 kg/m2 for men and 5.7 kg/m2 for women. These values are comparable to DXA-based standards, allowing for accessible screening without radiation exposure.

Sarcopenic obesity (concurrent loss of muscle mass/strength and central obesity) significantly increases the risk of disability and mortality in older adults compared to obesity or sarcopenia alone.

Focus on preserving muscle mass through resistance exercise and adequate protein intake, rather than just focusing on weight loss. If you are older and carry extra weight, losing some fat while maintaining or building muscle is the most effective way to prevent disability and maintain independence.

High levels of sedentary behavior, specifically television viewing, are independently associated with an increased risk of becoming overweight, regardless of the amount of nonsedentary physical activity performed.

Limit your television viewing time. Even if you exercise, watching TV for more than 21 hours a week significantly increases your risk of gaining weight. Try to keep TV viewing to under 1 hour per week for optimal weight maintenance.

Increasing nonsedentary activity by 10 MET-hours per week predicts a small but significant decrease in BMI (approx 0.03 units), whereas increasing TV viewing by 10 hours per week predicts a small but significant increase in BMI (approx 0.05 units).

Small changes in behavior add up. Adding just one hour of moderate exercise (like squash or running) per week can help lower your BMI slightly, while cutting 10 hours of TV time can prevent a small BMI increase. Focus on these small, sustainable shifts.