Browse the evidence

Evidence regarding the impact of workplace physical activity and nutrition interventions on productivity is limited and insufficient.

Employers should be cautious when expecting significant productivity gains from workplace health interventions, as the current evidence base is limited and insufficient.

Low energy availability causes a 'sick euthyroid' profile with decreased T3 and increased reverse T3, reducing energy expenditure as an adaptive response.

Low energy intake can lower your T3 levels as a way to conserve energy. This is a normal adaptation, not necessarily a thyroid disease. Focus on eating enough to support your activity level, which should normalize your thyroid hormones.

Eucaloric diets that are very low in fat and high in simple sugars markedly stimulate de novo fatty acid synthesis, leading to increased plasma triglycerides proportional to the amount of synthesis.

If you eat a diet that is very low in fat and high in simple sugars (like high sugar/starch ratios), your body will synthesize more fat from those carbohydrates, which raises your blood triglycerides. This happens regardless of whether you are lean or obese, and it is not driven by your insulin levels. To manage triglycerides, avoid extreme low-fat diets that are high in simple sugars.

Interindividual variability in triglyceride response to low-fat, high-carb diets is determined by the 24-hour pattern of fatty acid synthesis (constant vs. diurnal), not by body mass index or insulin levels.

Not everyone reacts to low-fat, high-carb diets with high triglycerides. Your response depends on whether your body maintains high fat synthesis constantly throughout the day or only spikes after meals. Those with 'constant' high synthesis have much higher triglycerides, regardless of their weight or insulin levels.

A reduced ratio of branched-chain amino acids (BCAA) to aromatic amino acids (AAA) in plasma is a specific metabolic signature of PCOS that is independent of obesity and insulin resistance, distinguishing it from type 2 diabetes profiles.

Your amino acid profile, specifically the balance between BCAA and AAA, is a unique fingerprint of PCOS. This helps doctors distinguish your condition from type 2 diabetes, even if you have insulin resistance. This distinction is important for tailoring the right treatment strategy for your specific metabolic needs.

Ovulatory dysfunction in PCOS is associated with elevated levels of serine, threonine, phenylalanine, tyrosine, and ornithine, suggesting that increased ovarian uptake of these amino acids contributes to anovulation.

If you struggle with anovulation, your body's handling of certain amino acids (serine, threonine, etc.) might be a key factor. This insight can help fertility specialists design more targeted treatments to support ovulation, addressing the metabolic root cause alongside hormonal therapies.

There is a curvilinear (inverted-U) relationship between GDP per capita and BMI: weight gain increases with development in low-income countries but decreases or levels off in high-income countries.

In developing economies, rising wealth often leads to higher obesity rates due to dietary changes. However, as countries become wealthier, these rates tend to stabilize or decrease, suggesting that long-term development can improve health outcomes.

Women's empowerment is positively associated with increased BMI, particularly in high-income countries.

As women gain more social and economic empowerment, there may be an increase in obesity rates due to lifestyle changes. Policymakers should ensure that healthy food options are accessible and convenient for working women.

Obestatin, a peptide derived from the same gene as ghrelin, suppresses food intake and decreases body weight gain, acting as an anorexigenic counter-regulator to ghrelin.

Obestatin is a peptide derived from the same gene as ghrelin but has the opposite effect: it suppresses food intake and reduces body weight gain. It acts as a natural brake on appetite, balancing the hunger signals sent by ghrelin.

Intermittent Hypoxic Training (IHT) provides no significant additional benefit for sea-level performance improvement compared to identical training performed in normoxia.

Do not rely on Intermittent Hypoxic Training (IHT) to boost your sea-level performance. If you are training at altitude but living at sea level, you are likely getting less benefit than if you just trained at sea level because you cannot maintain the same power or speed. Focus on high-intensity training in normoxia instead.

SIRT1 activation or overexpression increases PGC-1α gene transcription and mRNA expression in skeletal muscle cells through a mechanism involving direct binding to the PGC-1α promoter and interaction with the myogenic factor MyoD.

Skeletal muscle adaptation to metabolic demands involves SIRT1 regulating the expression of PGC-1α, a key master regulator of mitochondrial biogenesis. This process requires the interaction of SIRT1 with MyoD. While SIRT1 activators exist, their ability to increase PGC-1α transcription depends on the cellular environment and the presence of myogenic factors, suggesting that exercise (which induces MyoD and metabolic changes) is a critical co-factor for this pathway.

COVID-19 pandemic lockdown restrictions significantly increase total sedentary behavior (SB) in university students, with increases averaging 1.93 hours per day on weekdays and 1.30 hours per day on weekends compared to pre-pandemic baselines.

Lockdowns and remote work/study environments naturally increase sedentary time by nearly 2 hours daily. To counteract this, you must intentionally schedule non-sedentary activities (e.g., walking meetings, standing desks, or home workouts) because the default environment will pull you toward sitting.

Female university students spend significantly more total time on sedentary behavior than male students during pandemic restrictions, with females averaging 14.19 hours/day on weekdays and 15.22 hours/day on weekends compared to males' 12.90 and 14.10 hours respectively.

Women in lockdown environments tend to accumulate more sedentary time than men. If you are female, be extra vigilant about scheduling movement, as you may be more susceptible to the sedentary pull of remote work/study environments.

Dietary supplements carry a significant risk of inadvertent doping violations due to contamination, despite widespread use among athletes.

Be extremely cautious with dietary supplements. Many are contaminated with banned substances. Consult a qualified professional and use third-party tested supplements to avoid accidental doping violations.

Japanese American women exhibit significantly greater abdominal and visceral adiposity compared to Caucasian women when matched for Body Mass Index (BMI) and total body fat mass, primarily due to lower peripheral (leg) fat storage rather than increased total fat accumulation.

If you are an Asian woman, standard BMI charts may underestimate your health risks. Even if your weight is 'normal' or 'overweight' by standard definitions, you may carry dangerous levels of visceral fat. Focus on waist-to-hip ratio and visceral fat metrics rather than just scale weight. Prioritize lifestyle interventions that reduce visceral fat, such as aerobic exercise and managing insulin sensitivity, regardless of your total body weight.

During the luteal phase of the menstrual cycle, healthy women exhibit significantly reduced plasma levels of amino acids and lipids, indicating an anabolic state driven by progesterone that increases metabolic vulnerability to conditions like PMS and PMDD.

If you experience PMS or PMDD symptoms, your body is likely in a metabolically demanding 'anabolic' state during the luteal phase (post-ovulation) where amino acids and lipids are being utilized for tissue preparation. This creates a window of vulnerability. While this paper does not prescribe a specific diet, it suggests that ensuring sufficient protein and nutrient intake during this phase may help support the body's increased metabolic demands and potentially mitigate symptoms.

Exposure to environmental metabolic disruptors (e.g., BPA, phthalates, TBT) during critical developmental windows (in utero, early childhood) permanently alters metabolic programming, increasing susceptibility to obesity, diabetes, and metabolic syndrome later in life.

Focus on reducing exposure to endocrine-disrupting chemicals, especially during pregnancy and early childhood. Avoid heating food in plastic containers, minimize use of canned goods with BPA linings, and reduce contact with thermal paper receipts. This is a preventative strategy to protect metabolic health.

Reducing exposure to environmental chemicals and improving nutrition during development can prevent obesity and metabolic diseases.

Use glass or stainless steel containers for food and water. Avoid heating food in plastic. Choose fresh foods over canned when possible. This is especially important for pregnant women and young children.

In adult mice with progressive AgRP neuron degeneration, de novo neurogenesis in the hypothalamus serves as a compensatory mechanism to maintain energy balance; blocking this proliferation causes significant decreases in food intake and body adiposity.

This research suggests that the brain has a built-in repair mechanism for energy regulation when specific hunger-signaling neurons are lost. While this doesn't translate to a direct intervention for healthy people yet, it highlights the hypothalamus's plasticity. For now, maintaining metabolic health through diet and exercise remains the primary way to support these systems, as the paper shows that blocking natural cell proliferation leads to weight loss and reduced food intake in compromised models.

Ketogenic diets increase the risk of cardiovascular disease markers, specifically LDL-C elevation, which persists even with weight loss, and are associated with increased risks of kidney stones and chronic kidney disease.

Monitor your LDL cholesterol closely if you follow a ketogenic diet, especially if it is high in animal fats. The risk of kidney stones and chronic kidney disease also increases with high animal protein intake.

Oxidative stress, driven by excessive reactive oxygen species (ROS) from both endogenous (mitochondrial dysfunction, NOX activity) and exogenous (air pollution, UV, smoking) triggers, is a central causal mechanism in cellular senescence and the pathogenesis of aging-related diseases including neurodegeneration, cardiovascular disease, and cancer.

Aging and many chronic diseases are linked to cellular damage from oxidative stress. You can mitigate this by reducing exposure to external triggers like air pollution, UV radiation, and smoking, and by maintaining healthy lifestyle habits such as regular exercise and a balanced diet rich in antioxidants, which help manage internal ROS levels.

Mild hypoglycemia (a transient drop in circulating glucose) activates limbic-striatal brain regions and increases the desire for high-calorie foods, while euglycemia activates the medial prefrontal cortex to exert inhibitory control over food motivation.

If you experience strong cravings for junk food a few hours after eating, it may be due to a drop in blood sugar (hypoglycemia) rather than just the food itself. To reduce these cravings, consider strategies that prevent sharp drops in glucose, such as eating smaller, more frequent meals or choosing foods that stabilize blood sugar, especially if you are in an environment with lots of food cues.

Obese individuals lack the prefrontal cortical activation seen in non-obese individuals during euglycemia, resulting in a loss of glucose-linked inhibitory control over food motivation.

For obese individuals, the brain's natural 'brake' on food desire (mediated by the prefrontal cortex in response to normal blood sugar) may be less effective. This suggests that relying solely on willpower during normal eating times might be biologically harder, and strategies to stabilize blood sugar or reduce food cues are particularly important.

Exenatide (2 mg once weekly) significantly reduces alcohol cue reactivity in the ventral striatum and septal area in patients with Alcohol Use Disorder, but does not significantly reduce heavy drinking days in the general AUD population.

Exenatide, a weekly injection used for diabetes and obesity, changes how the brain responds to alcohol cues in addicted individuals, potentially reducing the 'pull' of drinking triggers. However, this neurobiological change did not automatically lead to fewer heavy drinking days for most patients in this study. It suggests that while the drug modifies reward processing, it may not be sufficient as a standalone treatment for reducing actual alcohol consumption in the general AUD population without additional behavioral support.