Browse the evidence

Acute ingestion of 75g glucose reduces regional cerebral blood flow (CBF) in appetite and reward-regulating brain regions (hypothalamus, striatum, insula), whereas fructose fails to produce this deactivation, suggesting glucose promotes satiety signaling while fructose does not.

Eating 75g of glucose triggers brain signals that reduce activity in areas controlling hunger and reward, promoting a feeling of fullness. Eating the same amount of fructose does not trigger these specific brain satiety signals, which may explain why high-fructose diets are associated with increased food intake and weight gain.

The ER22/23EK polymorphism in the glucocorticoid receptor gene confers relative resistance to glucocorticoids, resulting in a healthier metabolic profile characterized by lower fasting insulin, increased insulin sensitivity, and lower cholesterol levels.

If you carry the ER22/23EK variant, your body naturally handles glucocorticoids differently, leading to better insulin sensitivity and lower cholesterol. This is a protective genetic factor. Focus on maintaining this advantage through standard healthy living, as your biology already supports a favorable metabolic profile compared to non-carriers.

The ER22/23EK polymorphism is associated with increased lean body mass and muscle strength in young adult males, and reduced abdominal fat measures in young adult females, due to relative glucocorticoid resistance.

For young adults carrying the ER22/23EK variant, your body composition may naturally favor higher muscle mass in men and lower abdominal fat in women. This is a genetic advantage. Focus on resistance training to maximize this potential in men, and maintain a healthy lifestyle to preserve this favorable fat distribution in women.

Aging causes anabolic resistance to protein intake, characterized by a blunted muscle protein synthetic response to amino acids, which contributes to sarcopenia.

As you age, your muscles become less sensitive to protein. To build or maintain muscle, you likely need to consume more protein per meal (specifically leucine-rich sources) or time it precisely around exercise, rather than just eating the standard amount spread out.

A single night of partial sleep restriction (4 hours) induces insulin resistance in healthy subjects by reducing both hepatic and peripheral insulin sensitivity.

If you only get 4 hours of sleep, expect your body to handle glucose less efficiently the next day, even if you are healthy and lean. This means your blood sugar may stay higher after meals, and your body is less effective at storing glucose in muscles. Prioritize sleep duration to maintain metabolic health.

Prepregnancy consumption of high dietary fiber (specifically cereal and fruit) and low dietary glycemic load is associated with a significantly reduced risk of developing gestational diabetes mellitus (GDM).

To lower your risk of gestational diabetes before and during pregnancy, prioritize foods high in fiber, specifically from cereal (whole grains) and fruit sources, while minimizing foods that cause rapid spikes in blood sugar (high glycemic load). Aim for at least 10g more of total fiber or 5g more of cereal/fruit fiber per day as part of your pre-pregnancy diet.

Vitamin D signaling in innate immune cells (macrophages/dendritic cells) stimulates the intracrine synthesis of 1,25-dihydroxyvitamin D, which directly induces the expression of antimicrobial proteins (cathelicidin, beta-defensin 2) and enhances autophagy to combat intracellular pathogens like Mycobacterium tuberculosis.

Ensure your Vitamin D levels are sufficient, as the immune system needs this nutrient to produce antimicrobial proteins that fight bacteria and viruses. This is not just about bone health; your immune cells actively use Vitamin D to fight infections. If you are deficient, your immune cells cannot effectively produce these protective proteins, regardless of how much you take.

Vitamin D signaling suppresses proinflammatory T helper 1 (Th1) and Th17 cells while inducing immunotolerogenic T-regulatory (Treg) responses, thereby modulating adaptive immunity and reducing inflammation.

If you have an autoimmune condition or chronic inflammation, maintaining adequate Vitamin D levels may help regulate your immune system by reducing harmful inflammation and promoting tolerance. However, do not expect it to cure these conditions, as clinical trials show only modest effects.

Female reproductive function (menarche and ovulatory cycles) requires a critical minimum body fat percentage (approximately 17% for menarche onset and 22% for cycle maintenance), below which hypothalamic dysfunction causes amenorrhea.

If you are female and experiencing irregular periods or amenorrhea, check your body fat percentage, not just your weight. If your body fat drops below ~17-22%, your reproductive system may shut down. To restore cycles, you likely need to gain fat or reduce exercise intensity, even if your total body weight remains the same.

Women with PCOS have a significantly higher prevalence of impaired glucose tolerance (IGT) and type 2 diabetes (T2DM) compared to women without PCOS, with the magnitude of risk varying by ethnicity.

If you have PCOS, you are at a significantly higher risk for pre-diabetes and type 2 diabetes than women without PCOS, regardless of your weight. You should undergo regular screening (like an OGTT) as recommended by your doctor, rather than waiting for symptoms to appear.

Consumption of strawberries (approx. 50g freeze-dried powder or 500g fresh daily) significantly attenuates postprandial inflammatory responses (CRP, IL-6) and improves insulin sensitivity in overweight adults.

Include strawberries in your meals, especially those high in carbs. Eating about 10g of freeze-dried strawberry powder (or a standard serving of fresh berries) with your meal can significantly blunt the inflammatory spike and insulin response that typically follows eating.

Insulin reduces whole-body protein breakdown (proteolysis) in a dose-dependent manner in healthy postabsorptive men, primarily by suppressing the release of leucine from body protein stores.

In the fasted state, your body's insulin levels act as a switch to stop muscle breakdown. Higher insulin levels (within physiological ranges) more effectively suppress protein breakdown. This is why maintaining some level of insulin (e.g., via protein intake) can help preserve muscle mass during fasting or caloric deficits.

Severe testosterone deficiency in young men causes marked decreases in whole-body protein synthesis and fat-free mass, alongside increased adiposity and decreased muscle strength, independent of changes in systemic GH or IGF-I production.

For young men, maintaining normal testosterone levels is critical for preserving muscle mass and preventing fat gain. If testosterone drops significantly (e.g., due to medical treatment or pathology), you will lose muscle and gain fat even if your growth hormone levels remain normal. This is not just about 'energy balance'; the hormone directly alters how your body processes protein and fat.

Men with type 2 diabetes have a significantly higher prevalence of obstructive sleep apnoea (OSA) compared to the general population, with diabetes acting as an independent risk factor even after controlling for BMI.

If you have type 2 diabetes and experience daytime fatigue or snoring, ask your doctor about screening for sleep apnoea. This condition is much more common in your demographic than in the general population and may not be detected by BMI alone. Treating OSA (e.g., with CPAP) can improve sleep quality and potentially cardiovascular health.

Low circulating glycine levels are consistently associated with obesity, type 2 diabetes, and non-alcoholic fatty liver disease, and prospective studies indicate that decreased plasma glycine is a strong predictive factor for incident glucose intolerance and type 2 diabetes.

If you have obesity or type 2 diabetes, your blood glycine levels are likely lower than average, which is linked to higher insulin resistance. While eating more glycine-rich foods (like vegetable proteins) might help, the root cause involves how your body makes and uses glycine, influenced by your gut bacteria. Focus on overall metabolic health improvements (weight loss, exercise) which are associated with improved glycine concentrations.

Acute growth hormone (GH) response to resistance exercise increases in older women after 21 weeks of strength training, while basal hormone levels remain unchanged.

You don't need to worry about low basal hormones; your body's acute response to exercise can improve with training. Consistent resistance training is the key lever.

The 10,12 CLA isomer is primarily responsible for the fat-loss effects in animal models but causes insulin resistance in humans, whereas the 9,11 isomer may have different metabolic effects.

Most CLA supplements contain a mix of isomers, but the 10,12 isomer is the one that reduces fat in animals but causes insulin resistance in humans. If you take CLA, you are likely consuming this isomer, which may harm your metabolic health.

Short habitual sleep duration (≤6 hours) and specific insomnia symptoms (sleep continuity disturbance, early-morning awakening, and combined symptoms) significantly increase the incidence of hypertension in adults.

Prioritize consistent sleep duration of 7-8 hours and address sleep maintenance issues (waking up during the night) or early morning awakenings, as these specific patterns are linked to higher blood pressure risk. While difficulty falling asleep (DFA) was not significantly linked in this analysis, chronic sleep fragmentation (SCD) and early awakening (EMA) are. If you have trouble staying asleep or waking up too early, discuss this with your doctor as part of hypertension prevention.

Testosterone replacement therapy reverses glucocorticoid-induced bone loss and muscle wasting in hypogonadal men, increasing lumbar spine bone density by 5.0% and restoring lean body mass.

If you are a man on long-term steroids (like for asthma) and have low testosterone, testosterone replacement therapy can significantly strengthen your bones and restore muscle mass. The treatment involves monthly injections and is generally well-tolerated, though it may lower 'good' cholesterol (HDL). The benefits for bone health and muscle mass often outweigh the risks for men with serious conditions requiring steroids.

Low testosterone in men with type 2 diabetes and obesity is associated with increased cardiovascular disease risk and erectile dysfunction, mediated by visceral adiposity and proinflammatory cytokines.

If you have type 2 diabetes and are obese, getting your testosterone checked is important. Low levels are linked to higher heart disease risk and sexual dysfunction. Treatment with testosterone replacement may help, but it must be done carefully with monitoring for side effects, especially in older men.

Testosterone replacement therapy improves insulin sensitivity, reduces central adiposity, and improves sexual function in hypogonadal men with type 2 diabetes or metabolic syndrome.

If you have type 2 diabetes and low testosterone, TRT can improve your insulin sensitivity, reduce belly fat, and boost your sex drive and erectile function. It should be part of a broader plan including diet and exercise, and requires careful monitoring by a doctor.

Obesity superimposed on aging exacerbates chronic low-grade inflammation (inflammaging), which drives insulin resistance and increases the risk of age-related diseases such as type-2 diabetes, rheumatoid arthritis, and cognitive impairment.

If you are older and carrying extra weight, your body is likely in a state of chronic, low-grade inflammation that increases your risk for diabetes, heart disease, and cognitive decline. This isn't just about appearance; it's a biological process. Managing this risk involves addressing the underlying inflammation and metabolic health, not just weight loss alone.

Obesity negatively impacts the response to therapy in Rheumatoid Arthritis (RA), reducing the likelihood of achieving sustained remission with both conventional and biologic agents.

If you have Rheumatoid Arthritis and are obese, your current medications (including biologics) may be less effective at putting your disease into remission. This is due to biological factors like adipokines and inflammation. Discussing weight management alongside your RA treatment plan may improve your chances of achieving remission.

Mid-life obesity is associated with an increased risk of dementia and Alzheimer's disease later in life, whereas late-life obesity may show a paradoxical protective effect or no increased risk.

Maintaining a healthy weight in mid-life is crucial for reducing your risk of dementia and Alzheimer's disease later in life. While the relationship between weight and dementia in old age is complex, keeping your weight in a healthy range during your 40s and 50s is a proven way to protect your brain health.