Browse the evidence

Time-restricted eating (8-hour window) combined with resistance training improves upper-body high-speed strength (peak force and dynamic strength index) compared to habitual diet, while potentially impairing lower-body explosive performance.

If you are training for upper-body explosive power (like throwing or punching), an 8-hour eating window combined with heavy resistance training may boost your performance more than eating normally. However, if your goal is lower-body explosiveness (like jumping or sprinting), sticking to your normal eating schedule might yield better results. Body composition changes (fat loss) were similar in both groups.

Licensed weight-lowering pharmacotherapies (GLP-1RAs, naltrexone/bupropion, phentermine/topiramate) improve self-reported physical function, but do not significantly improve objectively measured physical function, cardiorespiratory fitness, or physical activity levels.

If you are using FDA/EMA-approved weight loss medications, expect improvements in how you feel you function in daily life (self-reported physical function). However, do not expect these medications alone to significantly boost your actual exercise capacity, VO2 max, or daily activity levels without dedicated exercise training. The benefits are modest and primarily subjective.

In individuals with overweight or obesity at high risk of type 2 diabetes, a trajectory of weight loss followed by weight regain results in a net loss of fat-free mass (FFM) despite fat mass (FM) returning to baseline levels.

If you are overweight or obese and have experienced a cycle of losing weight and then gaining it back, be aware that your body composition may have worsened even if your weight is back to where it started. Specifically, you may have lost muscle mass (fat-free mass) while regaining fat. To counteract this, prioritize resistance training and adequate protein intake during any future weight loss attempts to preserve muscle, as simply returning to your starting weight does not restore your previous body composition.

A trajectory of weight gain followed by weight loss results in a net gain in fat mass (FM) despite fat-free mass (FFM) returning to baseline levels.

If you have gained weight and then lost it back to your starting weight, your body composition may not be the same as it was before. You may have more fat and less muscle than you did initially. To ensure you are maintaining a healthy body composition, incorporate strength training and monitor body composition metrics, not just total body weight.

Diet-induced weight loss reduces left ventricular mass (LVM) in adults with overweight or obesity, whereas adding moderate-to-vigorous physical activity (≥150 min/week) to diet-induced weight loss preserves LVM.

If you are overweight or obese, losing weight through diet alone will reduce your heart's muscle mass. However, if you combine that diet with at least 150 minutes of moderate-to-vigorous exercise per week, your heart muscle mass is preserved. Both outcomes may be favorable, but preserving heart mass through exercise might be a beneficial adaptation alongside weight loss.

Bariatric surgery significantly reduces all-cause mortality, disease-specific mortality (cancer, cardiovascular, diabetes), and major adverse cardiovascular events (MACEs) in patients with severe obesity compared to matched non-surgical controls.

For individuals with severe obesity, bariatric surgery is a highly effective intervention for reducing the risk of death from cancer, heart disease, and diabetes, as well as preventing major cardiovascular events. It offers superior long-term outcomes compared to lifestyle changes alone for this population. Patients should discuss these benefits with their healthcare providers to determine if they are candidates.

Regular physical exercise prevents age-related skeletal muscle dysfunction, including loss of strength and mitochondrial capacity, by inducing structural remodeling and metabolic adaptations.

Start or maintain regular physical activity, combining aerobic and resistance exercises, to protect your muscles from age-related decline. This is one of the most effective ways to maintain strength, mitochondrial health, and metabolic function as you age.

GLP-1 receptor agonists for obesity treatment cause significant loss of lean body mass (approximately 20-25% of total weight reduction in men and 10-15% in women) and bone density, particularly when rapid weight loss occurs without structured resistance training.

If you are taking a GLP-1 medication for weight loss, you will likely lose some muscle along with fat. To protect your strength and metabolism, you must engage in resistance training (weight lifting) and ensure you are eating enough protein. This is especially important if you are losing weight quickly.

Regular physical activity, including aerobic, resistance, balance, and dual-task training, reduces the risk of dementia and cognitive decline by enhancing neurogenesis, improving cerebral blood flow, and increasing brain-derived neurotrophic factor (BDNF).

Aim for 150-300 minutes of moderate aerobic activity (like brisk walking) or 75-150 minutes of vigorous activity per week. Add strength and balance exercises twice a week. If you prefer cultural practices like Tai Chi or yoga, these are excellent alternatives that also support cognitive health. Start with what you enjoy and gradually increase intensity.

Current obesity treatments (behavioral, pharmacological, surgical) are effective but often result in weight regain, and their long-term success is limited by unchanged environmental factors.

Obesity treatments are effective but not permanent cures. You need to manage your weight long-term, possibly using a combination of treatments, and be prepared for potential weight regain if you stop.

In older adults with overweight/obesity and type 2 diabetes, losing weight while simultaneously gaining skeletal muscle mass significantly reduces the risk of adverse cardiovascular events compared to weight gain or weight loss accompanied by muscle loss.

For older adults with excess weight and diabetes, simply losing weight on the scale is not enough to protect the heart. You must preserve or build muscle during weight loss. This likely requires resistance exercise combined with adequate protein intake, rather than dieting alone. Losing weight while losing muscle provides no cardiovascular benefit compared to gaining weight.

Among individuals who lose weight, a higher ratio of skeletal muscle mass loss to total weight loss (SMMC/WC) is associated with a significantly increased risk of cardiovascular events, with risk doubling when muscle loss accounts for approximately 50% of weight loss.

If you are losing weight, monitor how much of that loss is muscle. If you lose muscle equal to half your total weight loss, your cardiovascular risk effectively doubles compared to someone who preserves muscle. To mitigate this, prioritize resistance training and protein intake during caloric restriction.

One-anastomosis gastric bypass (OAGB) and Roux-en-Y gastric bypass (RYGB) result in significantly greater reductions in areal bone mineral density (aBMD) at the total hip, femoral neck, and lumbar spine compared to sleeve gastrectomy (SG) within the first year post-surgery.

If you are considering bariatric surgery, know that bypass procedures (OAGB and RYGB) lead to greater bone density loss at the hip and spine than sleeve gastrecty (SG) in the first year. This is likely due to malabsorption of calcium and vitamin D. You should discuss bone health monitoring and supplementation strategies with your surgeon, especially if you choose a bypass procedure.

Achieving optimal levels of waist circumference, glomerular filtration rate, and urine albumin-to-creatinine ratio (each weighted 2 points) and glycated hemoglobin/blood pressure (each weighted 1 point) is significantly associated with a lower risk of heart failure in type 2 diabetes.

For individuals with Type 2 Diabetes, managing heart failure risk requires a multi-faceted approach. Prioritize achieving target levels for waist circumference, kidney function (GFR and urine albumin), blood pressure, and blood sugar. The study suggests that controlling waist circumference and kidney markers may offer greater protection against heart failure than controlling blood pressure or blood sugar alone.

Longitudinal improvement in the cardiometabolic health score is significantly associated with a lower risk of heart failure.

If you have Type 2 Diabetes, working to improve your cardiometabolic health over time—such as reducing waist circumference, improving kidney markers, or better controlling blood pressure and blood sugar—can significantly lower your risk of developing heart failure, even if you started with a lower health score.

Obesity increases the risk and severity of acute pancreatitis (AP) through mechanisms including gallstone formation, hypertriglyceridemia-induced lipotoxicity, and intrapancreatic fat infiltration.

If you have obesity, your risk of acute pancreatitis is significantly higher due to factors like gallstones and fat breakdown products. Losing weight, particularly visceral fat, can reduce this risk.

Steep, excessive weight loss (>17% average) during the post-intervention follow-up phase in older adults with type 2 diabetes is strongly associated with increased mortality risk, particularly when the loss is unintentional.

If you are an older adult with type 2 diabetes, do not pursue aggressive weight loss strategies without medical supervision. Monitor your weight closely; if you lose more than 5% of your body weight unintentionally or rapidly, consult your doctor immediately, as this may indicate underlying health issues like frailty or depression rather than improved health.

Implementing 2020–2025 DGA-aligned school meal standards (limiting added sugars and sodium, increasing whole grains) reduces childhood BMI and systolic blood pressure, leading to significant long-term reductions in cardiovascular disease, diabetes, and cancer mortality in adulthood.

For policymakers and school administrators, updating school meal standards to limit added sugars and sodium while increasing whole grains is a high-impact intervention. It modestly improves children's immediate health (BMI, BP) and yields massive long-term societal benefits, including thousands of prevented deaths and billions in healthcare savings in adulthood.

Higher consumption of ultra-processed foods (UPFs) is associated with an increased risk of developing type 2 diabetes mellitus (T2DM), with hazard ratios typically ranging from 1.12 to 1.53 for incremental increases in UPF intake.

Limit your intake of ultra-processed foods, particularly those high in added sugars, saturated fats, and specific additives like emulsifiers (e.g., carrageenan) or containing endocrine disruptors from packaging (e.g., BPA). Focus on reducing sugary beverages and processed meats, as these show the strongest link to T2DM risk, while noting that some processed items like whole grain breads may not carry the same risk.

Skeletal muscle hypertrophy following resistance training is associated with distinct, cell-type-specific non-coding RNA (ncRNA) expression patterns, including MYREM (myonuclear), MEG3 (satellite cells), and CARMN (linear association with lean mass gain), which mediate growth via discrete functional pathways rather than uniform bulk tissue changes.

Resistance training works for most people (61% in this large multi-study analysis). If you are not seeing expected gains, it may not be that you 'can't grow,' but that your body uses different molecular switches (ncRNAs) than the average responder. Focus on consistent, supervised resistance training; individual molecular responses vary, but the mechanical stimulus is the primary driver. Do not use 'non-response' as an excuse to stop training, as measurement error often masks small gains.

A one-week complete cessation from resistance training (deload) at the midpoint of a 9-week program does not enhance hypertrophy, power, or local muscular endurance compared to continuous training, and results in inferior strength gains.

If your goal is maximizing strength, do not take a full week off from resistance training. Continuous training yields better strength gains than a one-week complete break. If you take a break for hypertrophy, expect no loss in muscle size, but do not expect any extra growth. Use deloads to manage fatigue, not to force adaptation.

Back squat training elicits greater improvements in lower limb dynamic strength on a nonspecific strength test (45° leg press) compared to front squat training in recreationally trained females, while both variations produce similar hypertrophic adaptations in the lateral thigh.

If your goal is maximum strength, prioritize the back squat. It allows you to lift heavier loads, which translates to better strength gains on other exercises like the leg press. If your goal is just muscle growth in the quads, either squat works equally well, so choose the one you can perform with better technique and less joint pain. You do not need to force yourself to do front squats if they cause shoulder discomfort; the back squat will get you the same muscle growth.

Sarcopenic obesity is a distinct clinical phenotype characterized by high fat mass and low skeletal muscle mass/function, associated with increased risks of frailty, mortality, and metabolic complications, requiring specific diagnostic algorithms (e.g., ESPEN-EASO) for identification.

If you have obesity and are experiencing weakness, fatigue, or functional decline, especially as you age, ask your doctor about sarcopenic obesity. It is not just 'being overweight'; it involves muscle loss which increases health risks. Diagnosis requires specific tests for muscle mass and strength, not just BMI.

The same 25g whey + 5g collagen blend increases myofibrillar protein synthesis during exercise recovery, but does NOT significantly increase muscle connective protein synthesis in the exercised leg compared to placebo.

If you are doing resistance training, your body already significantly boosts connective tissue synthesis. Adding a whey-collagen blend won't necessarily boost connective tissue synthesis further in the working muscles compared to just placebo, though it does help muscle protein synthesis. Focus on the blend for muscle growth, but don't expect it to be a magic bullet for tendon repair in exercised muscles.