Browse the evidence

In patients with type 2 diabetes mellitus, higher body weight variability (fluctuation) is associated with a significantly increased risk of cardiovascular events and mortality, independent of mean body weight and traditional risk factors.

If you have type 2 diabetes, avoiding large swings in your body weight is just as important for your heart health as maintaining a healthy average weight. Try to maintain consistent lifestyle habits rather than cycling through intense diets and regain, as this variability is linked to higher risks of heart attacks and stroke.

Resistance exercise increases the turnover (synthesis and degradation) of individual muscle proteins without necessarily increasing net protein abundance or synthesis rates, particularly when performed under a high-fat, low-carbohydrate diet.

If you are doing resistance training, expect your muscles to remodel by breaking down and rebuilding proteins, even if you don't see immediate size gains. This is normal adaptation, not failure. Ensure you are recovering adequately, as this turnover process is energy-intensive.

GLP-1 receptor agonists for obesity treatment cause significant loss of lean body mass (approximately 38% of total weight loss) and muscle mass, increasing the risk of sarcopenia and bone loss, particularly in the absence of structured resistance training and adequate protein intake.

If you are taking a GLP-1 medication for weight loss, expect to lose some muscle along with fat. To protect your strength and metabolism, you must prioritize resistance training (weight lifting or bodyweight exercises) and ensure you are eating enough protein. Without these steps, you risk losing significant muscle mass, which can happen with any rapid weight loss method.

Short-term muscle disuse atrophy (4 days) in humans is driven by declines in muscle protein synthesis (MPS), not by increased muscle protein breakdown (MPB).

If you are immobilized or inactive for a few days, your muscle loss is caused by a drop in your body's ability to build new muscle protein, not by an increase in muscle destruction. To mitigate this, interventions should focus on stimulating muscle protein synthesis (e.g., through protein intake or resistance stimuli if possible) rather than just trying to block breakdown pathways.

Lean body mass is preserved on average in both TRF and MBD groups, but individual responses vary significantly, with some participants losing lean mass despite adequate protein intake.

While your group average lean mass stays stable, individual results vary. Ensure you are lifting weights and eating enough protein (1.4-2.0g/kg body weight or 2.3-3.1g/kg lean mass) to maximize the chance of preserving muscle while losing fat.

In individuals with type 2 diabetes, a history of cardiovascular disease and higher baseline BMI are associated with modestly poorer cognitive function following an intensive lifestyle intervention compared to standard care.

For individuals with type 2 diabetes who are obese or have a history of cardiovascular disease, intensive lifestyle interventions may not improve cognitive function and could be associated with modestly poorer outcomes compared to standard care. These individuals should discuss potential risks and benefits with their healthcare provider.

Person-specific characteristics (genetic, hormonal, psychosocial, and behavioral) significantly predict individual variability in weight loss response to obesity interventions, making precision medicine strategies potentially more effective than broad application of treatments.

Stop assuming a single diet or exercise plan works for everyone. Your body's unique genetics, hormones, and psychology dictate how you respond to treatment. Instead of blindly following a generic plan, look for early signs of response (like weight loss in the first few weeks) to decide whether to continue or switch strategies. If you have specific genetic conditions (like leptin deficiency), targeted medical therapies may be available, but for most, success depends on matching the intervention to your specific biological and psychological profile.

Replacing saturated fatty acids (SFA) from dairy foods with polyunsaturated fatty acids (PUFA) reduces LDL cholesterol but does not consistently reduce cardiovascular disease (CVD) risk or mortality, suggesting that LDL-C reduction alone is not a reliable predictor of CVD outcomes when the source is dairy.

Current guidelines suggest limiting saturated fats to reduce heart disease risk. However, this review indicates that replacing dairy saturated fats with polyunsaturated fats lowers LDL cholesterol but does not necessarily lower your actual risk of heart attacks or death. This suggests that simply counting saturated fat grams may be less important than the overall food matrix (e.g., eating whole dairy products) and other lipid markers like the LDL particle size.

High intake of saturated fatty acids from dairy foods is associated with neutral or negative (protective) associations with cardiovascular disease risk, unlike SFAs from other sources which may increase risk.

You do not need to restrict dairy foods to manage heart health risk. While general guidelines limit saturated fats, evidence suggests that the specific fats found in dairy (like C15:0 and C17:0) are associated with neutral or even protective effects on cardiovascular disease, unlike saturated fats from other sources.

Behavioral weight management programs (BWMPs) produce sustained improvements in cardiometabolic risk factors (blood pressure, lipid profile, glycemic control) for at least 5 years after program end, despite significant weight regain.

If you participate in a structured weight loss program, expect your blood pressure, cholesterol, and blood sugar to improve significantly. Even if you regain some weight after the program ends, these health benefits will likely persist for at least five years. Do not be discouraged by partial weight regain; the metabolic improvements are durable.

Short-term consumption of fast-food meals (a subset of UPFs) increases bile-tolerant bacteria (Collinsella, Parabacteroides, Bilophila) and decreases fiber-fermenting bacteria (Lachnospiraceae, Butyricicoccus).

Eating fast food for just 4 days can shift your gut bacteria, increasing bile-tolerant types and decreasing fiber-fermenting types. To maintain a healthy microbiome, limit fast food frequency and prioritize fiber-rich foods.

The statistical method used to analyze the relationship between muscle hypertrophy and strength gain significantly alters the observed correlation, with hierarchical linear modeling (HLM) revealing stronger within-individual associations than between-subject correlations or ANCOVA.

If you are designing a study or interpreting research on muscle growth and strength, do not rely on simple between-subject correlations (comparing Person A to Person B). Use within-subject analyses (like Hierarchical Linear Modeling) to see how an individual's growth relates to their strength gain. For practitioners, this means individual responses vary wildly; some people get strong without growing much, and some grow without getting proportionally stronger. Do not assume muscle size is the sole driver of strength.

High maximal fat oxidation (MFO) is associated with successful long-term weight loss maintenance, but the underlying mechanism differs from that in individuals who regain weight despite having similarly high MFO.

If you are trying to maintain weight loss, simply having a high capacity to burn fat isn't enough if your body is overloaded with lipids. Successful maintainers typically have higher cardiovascular fitness (V˙ O2max) and better muscle lipid handling proteins (CD36, FABPpm) compared to those who regain weight, who may have high fat oxidation simply because they have more fat available to burn. Focus on building fitness and muscle health rather than just chasing fat oxidation numbers.

Prevention and reversal of the transition from metabolically healthy obesity (MHO) to metabolically unhealthy obesity (MUO) requires multifaceted interventions targeting both adipose tissue intrinsic factors (e.g., promoting adipogenesis) and extrinsic drivers (e.g., hyperinsulinemia, circadian disruption), with lifestyle changes serving as the foundation but often requiring pharmacological or surgical augmentation for substantial weight loss and metabolic correction.

If you have obesity but normal metabolic markers (MHO), do not assume you are safe. Approximately half of people in this category will develop metabolic complications (MUO) over time. Focus on lifestyle changes (diet, exercise) to maintain metabolic health. If lifestyle changes are insufficient to prevent progression, consult a healthcare provider about pharmacological or surgical options to address underlying drivers like hyperinsulinemia or adipose dysfunction.

Eight weeks of resistance training significantly improves phase angle, a marker of cellular health, in obese older women, independent of significant changes in body fat percentage.

If you are an older woman with obesity, engaging in resistance training for just 8 weeks (3 times a week) can significantly improve your cellular health, as measured by phase angle. This improvement happens even if you don't lose much body fat. Focus on performing 8 exercises with 3 sets of 8-12 reps, progressively increasing the weight as you get stronger, rather than just focusing on the number on the scale.

Implementing a government-supported voluntary national sugar reduction policy targeting packaged foods and beverages results in significant long-term health gains, including reduced cardiovascular disease and diabetes incidence, and generates net cost savings for society.

Supporting government-led initiatives to reduce added sugar in packaged foods and beverages can significantly improve public health and reduce healthcare costs. This involves encouraging industry reformulation to meet specific sugar reduction targets, particularly for sugary drinks.

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.

Pharmacologic weight loss medications are effective only when used as adjuncts to lifestyle modifications; discontinuation of medication without sustained lifestyle changes leads to inevitable weight regain.

If you are prescribed a weight loss medication, understand that it is not a cure. It works best when you simultaneously adopt dietary changes and physical activity. If you stop the medication without having established sustainable lifestyle habits, you will likely regain the weight. The drug is an adjunct, not a substitute.

In resistance-trained men, low-load (20 RM) and moderate-load (10 RM) resistance training produce equivalent improvements in maximal strength and body composition when total load lifted is equated and sets are performed to volitional failure.

If you are an experienced lifter, you don't need to grind out heavy 1-5 RM reps to get strong or build muscle. You can use lighter weights (around 20 RM) as long as you take every set to near-failure and match the total amount of weight you lift (sets x reps x weight) to what you would do with heavier weights. This allows for strength and muscle gains similar to heavy training, potentially with less joint stress.

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.

Drop-set training on leg extensions produces greater non-uniform hypertrophy in the proximal and mid-rectus femoris compared to traditional training, while yielding equivalent strength gains and no differential hypertrophy in the vastus lateralis.

If your goal is to specifically target the Rectus Femoris (the muscle in the middle of your thigh) using leg extensions, using drop sets (reducing weight after failure) may yield better growth than standard sets. However, do not expect this to make you stronger or grow your Vastus Lateralis (outer thigh) any more than standard training would. For general strength and overall quad size, standard training is equally effective and likely less fatiguing.

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.