Browse the evidence

High levels of perceived psychological stress are significantly associated with poor sleep quality in medical students, with stressed students having an 86% prevalence of poor sleep compared to 64% in non-stressed students.

If you are a student or high-performer feeling stressed, recognize that your sleep problems are likely a symptom of that stress, not just a bad habit. The data shows stressed individuals are much more likely to have poor sleep. Instead of just forcing yourself to stay awake to study, address the stressor directly (e.g., through counseling or time management) because the stress itself is driving the sleep disruption. Prioritizing sleep hygiene is a medical recommendation for this population to break the cycle of stress-induced insomnia.

Lower academic performance (GPA < 4.25/5.0) is a significant predictor of poor sleep quality, with students in this group having nearly four times higher risk of poor sleep compared to high-performing peers.

If you are struggling academically, check your sleep. This study found that students with lower GPAs are much more likely to have poor sleep. While it might seem like you need to stay up to study, the data suggests a link between low performance and poor sleep. Addressing sleep hygiene might be part of the solution to improving both your rest and your grades, rather than viewing them as trade-offs.

Higher national household availability of ultra-processed foods is positively associated with higher national prevalence of obesity among adults, with each 1% increase in ultra-processed food energy share resulting in a 0.25 percentage point increase in obesity prevalence.

To reduce obesity risk, prioritize unprocessed or minimally processed foods (fruits, vegetables, meats, grains) and limit ultra-processed foods (packaged snacks, sugary drinks, ready meals). National policies should aim to make these ultra-processed options less available and affordable, as their increased presence in households correlates directly with higher obesity rates.

During COVID-19 confinement, Spanish adults significantly increased their adherence to the Mediterranean Diet (MedDiet) by reducing intake of fried foods, snacks, fast foods, red meat, pastries, and sweet beverages, while increasing consumption of olive oil, vegetables, fruits, and legumes.

If you are looking to improve your diet during a period of restricted movement or stress, focus on two actions: cut back on fried foods, snacks, fast food, red meat, pastries, and sugary drinks, while simultaneously increasing your intake of olive oil, vegetables, fruits, and legumes. This specific shift in food choices is strongly linked to better overall dietary adherence and may help prevent chronic diseases.

Quarantine leads to unhealthy dietary habits, specifically increased consumption of energy-dense, shelf-stable foods (high in sugar, salt, and trans-fats) and decreased intake of fresh fruits and vegetables, resulting in micronutrient deficiency and increased oxidative stress.

Stock up on shelf-stable healthy foods like frozen vegetables, canned beans, nuts, and whole grains. Avoid relying solely on processed, high-sugar, and high-salt shelf-stable foods. Aim to include antioxidants and vitamins in your diet to reduce oxidative stress and inflammation.

Quarantine leads to reduced physical activity and increased sedentary behavior, which rapidly reverses beneficial metabolic and cardiovascular adaptations, leading to insulin resistance, increased blood pressure, and higher cardiovascular risk.

Maintain physical activity through home-based exercises, online classes, or walking in small spaces. Aim to interrupt sedentary time every 30 minutes. Even short bouts of activity add up to weekly recommendations and help prevent the rapid loss of metabolic benefits.

Increasing dietary intake of omega-3 long-chain polyunsaturated fatty acids (LC-PUFAs) and maintaining an omega-6/omega-3 ratio of 2–4:1 is associated with a reduced risk of breast, prostate, colon, and renal cancers.

To support cancer prevention and overall health, aim to consume 2-3 servings of oily fish weekly to get 200-500 mg of EPA/DHA daily. If you have existing cardiovascular risks, medical guidance may suggest 1-4 grams daily. Crucially, try to lower your omega-6 to omega-3 ratio from the typical Western 20:1 down to 2-4:1 by reducing processed seed oils and increasing omega-3 sources.

Self-reported anxiety and depression during enforced lockdown significantly predict increased weight gain in adults with obesity, independent of exercise levels.

If you are feeling anxious or depressed, expect your weight to potentially increase. This is a common reaction to stress, not a personal failure. Focus on identifying 'comfort foods' that are healthier and manage portion sizes, as mental burden is a stronger driver of weight gain than exercise levels during lockdown.

Not consuming healthy foods (ignoring healthiness of food choices) is significantly associated with increased weight gain during lockdown.

Pay attention to the healthiness of your food choices. The study found that ignoring whether food is healthy or not was significantly linked to weight gain. Try to prioritize fruits, vegetables, and lean proteins, even if you are stressed.

Female samples experience significantly greater benefits from dietary interventions for both depression and anxiety symptoms compared to male samples.

If you are female, improving your diet may have a particularly strong positive impact on your mood and anxiety levels. While men also benefit, the evidence suggests women may see greater improvements. This highlights the importance of considering sex-specific factors in dietary interventions for mental health.

Saturated fat intake interacts with genetic variants (such as APOE4, APOA2, and obesity genetic risk scores) to modulate cardiovascular risk and obesity, suggesting that personalized dietary recommendations based on genetics may be beneficial for specific subgroups.

If you have a family history of high cholesterol or heart disease, you might be more sensitive to saturated fat. Consider getting genetic testing or consulting a professional to see if a lower saturated fat diet is beneficial for you, especially if you carry the APOE4 gene.

Regular moderate physical exercise acts as an antioxidant by upregulating endogenous defense systems (enzymes and non-enzymatic antioxidants), thereby protecting against oxidative stress and age-related decline.

Engage in regular, moderate physical activity (like walking or cycling) consistently. This trains your body to produce its own antioxidants, protecting you from aging and disease, rather than relying on supplements to fix damage from overexertion.

Supplementation with specific polyphenols (quercetin, resveratrol, curcumin) activates SIRT1, which modulates AMPK and mTOR pathways to support mitochondrial biogenesis and reduce oxidative stress.

If you are an endurance athlete, consider quercetin supplementation (1000mg/day) for 6 weeks to potentially reduce markers of oxidative stress (MDA). However, prioritize regular exercise as the primary driver of health.

Strenuous or excessive exercise without proper training adaptation can be detrimental, leading to increased oxidative stress, hormonal imbalance, and immune suppression.

Avoid excessive exercise if you are untrained. Start with moderate activity and progress gradually to allow your body to adapt and detoxify ROS effectively, preventing negative hormonal and immune effects.

Multisensory wearable sleep trackers (using HR, HRV, temperature, and motion) offer improved sleep stage classification (light, deep, REM) compared to motion-only devices, but still struggle with accurate wake detection and slow-wave sleep classification.

Multisensory wearables are better at distinguishing sleep stages than older models, but they are still not accurate enough for medical diagnosis. Use them to track general trends, not specific sleep stage durations.

Dietary resistant starch increases the production of satiety hormones GLP-1 and PYY, contributing to reduced adiposity and improved insulin sensitivity.

Incorporate resistant starches like cooled potatoes, legumes, or high-amylose maize flour into your diet. Start with small amounts to minimize digestive discomfort. This can help improve insulin sensitivity and promote satiety through natural hormone production.

The effectiveness of exercise for depression is moderated by participant sex and age, with specific modalities performing better for specific demographics.

To maximize benefits, consider your demographics. Women may find strength training and cycling more effective for depression. Men may find yoga, tai chi, or aerobic exercise combined with therapy more effective. Older adults may benefit more from yoga and aerobic therapy, while younger adults may benefit more from strength training.

Dietary consumption of tomatoes and tomato-based products provides bioactive compounds (lycopene, phenolics, vitamins) that act as antioxidants to neutralize reactive oxygen species, thereby reducing oxidative stress and ameliorating degenerative diseases such as cardiovascular disease, cancer, and cognitive decline.

Eat tomatoes regularly, especially cooked forms which may enhance lycopene bioavailability, to support long-term health. They are a potent source of antioxidants that help protect your cells from damage linked to heart disease and cancer. If you experience heartburn or allergies, limit intake or consult a professional for alternatives.

Tomato phytosterols (specifically beta-sitosterol, campesterol, and stigmasterol) reduce low-density lipoprotein cholesterol (LDL-C) by blocking cholesterol absorption in the intestine, contributing to cardiovascular disease prevention.

Include tomatoes in your diet to naturally support healthy cholesterol levels. The phytosterols in tomatoes help block cholesterol absorption. This is a passive, dietary way to support heart health without needing isolated supplements.

Tomato dietary fiber (soluble and insoluble) ameliorates bowel disorders, cancer, diabetes, cardiovascular diseases, and obesity by resisting intestinal digestion and promoting gut health.

Eat tomatoes for their fiber content to support digestive health and reduce risk of chronic diseases. The fiber helps regulate bowel movements and may assist in managing weight and blood sugar.

The Mediterranean diet, characterized by high intake of polyphenols, fiber, and omega-3 fatty acids, counteracts oxidative stress and insulin resistance in Type 2 Diabetes by activating the NRF2 antioxidant pathway and reducing pro-inflammatory eicosanoids.

Adopt a Mediterranean-style eating pattern focusing on vegetables, fruits, whole grains, legumes, nuts, and extra virgin olive oil. Limit meat and processed foods. This approach helps manage oxidative stress and insulin resistance through natural antioxidants and anti-inflammatory fats.

Intermittent fasting (IF) and time-restricted feeding (TRF) reduce oxidative stress and inflammation in Type 2 Diabetes by activating AMPK and SIRT3, which promotes autophagy and mitochondrial biogenesis.

Consider time-restricted feeding by limiting your eating window to 8-10 hours per day. If using intermittent fasting, restrict energy intake by 60% on 2-3 days a week. Monitor blood glucose closely, especially if taking diabetes medication, to avoid hypoglycemia.

Physical exercise induces transient oxidative stress (hormesis) which triggers adaptive responses, including increased antioxidant enzyme activity (SOD, CAT, GPx) and mitochondrial biogenesis, ultimately reducing baseline oxidative stress in Type 2 Diabetes.

Engage in regular physical exercise, including moderate-intensity, resistance, or high-intensity interval training. While exercise temporarily increases oxidative stress, this triggers your body to produce more antioxidant enzymes and improve mitochondrial health, reducing overall oxidative stress.

Exercise is generally safe with minimal adverse events, which are typically mild, transient, and comparable to control groups, though reporting of adverse events is often poor in studies.

Exercise is safe for most people. You might experience some muscle soreness, but serious side effects are rare. Do not let fear of injury stop you from exercising, as the benefits to your health and longevity are substantial.