Browse the evidence

A 3-month multicomponent mobile health intervention (smartphone app + smart band + brief counseling) produces statistically significant but clinically modest weight loss and body composition improvements in overweight/obese adults compared to brief counseling alone, but these benefits are not maintained at 12 months after device removal.

Using a smartphone app and fitness tracker for 3 months can help you lose a small amount of weight and improve body composition if you are overweight or obese. However, this benefit disappears after 3 months if you stop using the devices. To maintain weight loss, you must transition the habits learned during the 3-month period (like self-monitoring and dietary awareness) into your daily life without relying on the technology.

Six months of caloric restriction (25% deficit, with or without exercise, or low-calorie diet) does not significantly increase subjective hunger or decrease fullness compared to a weight-stable control group in overweight, non-obese adults.

If you are overweight but not obese, you can lose a significant amount of weight (around 10-14%) over 6 months by eating less (25% less than your needs) without necessarily feeling much hungrier than someone who isn't dieting. This suggests that hunger is not the insurmountable barrier it is often made out to be for this population. Focus on sustainable deficit rather than fearing extreme hunger.

Three weeks of total meal replacement (TMR) at 1120 kcal/day increases dorsolateral prefrontal cortex (dlPFC) activation and enhances its inhibitory functional connectivity over the nucleus accumbens and orbitofrontal cortex in response to food cues, compared to a typical food-based diet (TD).

If you are struggling with food cravings, a short-term (3-week) period of consuming only meal replacement shakes (around 1120 calories) may help 'reset' your brain's response to food. Unlike eating normal food in portions, this approach appears to strengthen the brain's executive control centers (dlPFC) and their ability to inhibit reward centers (nucleus accumbens) when seeing food. This leads to greater weight loss and reduced cravings compared to just eating less of regular food.

Low-carbohydrate/high-protein (LCHP) diets fail to produce significant weight loss or cardiovascular improvements in obese patients who do not maintain strict adherence, largely due to high attrition and reduced concordance over time.

If you try a low-carb diet and struggle to stick to it, don't blame yourself for lacking willpower; the diet itself may be unsustainable for your lifestyle. In this study, LCHP resulted in almost no weight loss because people stopped following it strictly. If you can't maintain strict adherence, a more structured approach like a VLCD with support might be more effective.

Adding weekly group support to the 5:2 diet improves short-term adherence and weight loss (at 6 weeks), but this advantage diminishes and becomes statistically non-significant by 12 months.

If you start the 5:2 diet, try to get some form of support for the first 6 weeks, such as a group session or a buddy system. This will help you lose more weight initially. However, be aware that this advantage may fade after a year, so focus on building sustainable habits rather than relying solely on support.

Smartphone-only apps for weight management produce a modest but statistically significant reduction in body weight and BMI in adults with overweight or obesity, but this effect is limited to a 4-6 month window and diminishes thereafter due to lack of personalization.

Use a smartphone app for weight loss if you can commit to using it daily for 4-6 months. Expect modest results (SMD -0.33) and be prepared for weight regain if you stop using it. To maximize success, choose an app that offers some level of personalization or feedback, as generic apps have high dropout rates. This is not a long-term solution without human support or advanced AI customization.

Manipulating energy density does not significantly alter the total amount of food consumed (in grams), meaning volume intake remains constant.

Do not worry about shrinking your portions. When you lower the energy density of your food (e.g., by adding vegetables), you can eat the same amount of food by weight. This helps maintain satiety and makes the diet easier to follow long-term.

Weight loss maintenance is difficult to sustain without continued structured intervention, as significant anthropometric improvements were not maintained 18 weeks post-intervention in either group.

Do not stop your healthy habits once you reach your goal weight. This study shows that without continued effort, the benefits of weight loss are likely to fade. Treat your diet and exercise routine as a permanent lifestyle change, not a temporary fix.

While VLEDs produce rapid initial weight loss, long-term maintenance (1-2 years) is variable and often incomplete, with average losses ranging from 0 to 13.1 kg, suggesting that VLEDs alone are insufficient for sustained weight loss without adjunct therapies.

Don't expect a VLED to be a one-time fix. You will lose weight fast, but you will likely regain some of it over the next year or two. To keep the weight off, you must use the VLED as a starting point and immediately engage in behavioral changes or medical support to maintain the loss.

Long-term weight loss (2 years) is equivalent between low-carbohydrate and low-fat diets when both are combined with comprehensive behavioral interventions.

If you are trying to lose weight long-term, do not obsess over whether you must cut carbs or fat. Focus on getting comprehensive behavioral support (counseling, tracking, lifestyle coaching). Both low-carb and low-fat diets resulted in the same amount of weight loss (7%) over two years when behavioral support was included. The specific macronutrient ratio is less important than the behavioral adherence supported by the program.

Incorporating self-efficacy (confidence in one's ability to perform a behavior) into the Health Belief Model significantly improves the prediction and modification of complex health-related behaviors compared to using the Health Belief Model alone.

To change complex health habits, you need two things: the belief that the change will help you (outcome expectation) AND the belief that you can actually do it (self-efficacy). If you feel you can't do it, break the behavior into smaller steps to build confidence through small wins, or watch someone similar to you succeed. Don't just rely on knowing it's good for you; build the skill and confidence to do it.

Wrist actigraphy provides a valid and reliable estimate of sleep duration and sleep/wake patterns in healthy adults and specific clinical populations, serving as a cost-effective alternative to polysomnography (PSG) for monitoring sleep variability and treatment effects.

Use a wrist actigraph for at least 7 nights to track sleep patterns, especially if you have insomnia or suspect a circadian rhythm disorder. It is more accurate than sleep logs for measuring total sleep time and variability, but do not rely on it for detailed sleep stage analysis or if you have significant movement disorders.

Prolonged sedentary time is independently associated with increased risk for all-cause mortality, cardiovascular disease, cancer, and type 2 diabetes in adults, regardless of physical activity levels.

Reduce your total sitting time throughout the day. Even if you exercise regularly, prolonged sitting increases your risk for heart disease, diabetes, and early death. Break up long periods of sitting with standing or light movement.

High levels of physical activity attenuate, but do not eliminate, the increased risk of all-cause mortality associated with high sedentary time.

If you exercise regularly, you still benefit from reducing your total sitting time. High physical activity lowers the risk associated with sitting, but does not eliminate it. Combine regular exercise with strategies to break up long periods of sitting.

Automatic scoring algorithms applied to wrist actigraphy data can distinguish sleep from wakefulness with approximately 88% accuracy, providing reliable estimates of sleep latency, total sleep time, and sleep efficiency comparable to polysomnography.

Wrist actigraphy with automated scoring is a reliable, non-invasive tool for monitoring sleep patterns in clinical and research settings. It offers accuracy comparable to expensive lab-based polysomnography for key metrics like sleep latency and total sleep time, making it a practical choice for long-term sleep assessment.

Low socioeconomic status (SES) is causally linked to higher prevalence of smoking, physical inactivity, and obesity, driven by mechanisms such as chronic stress, relative deprivation, and perceived limited benefits of healthy behavior rather than just lack of knowledge.

For individuals in lower socioeconomic positions, adopting healthy behaviors is not just a matter of knowing what is healthy. It is often hindered by chronic stress, lack of efficacy, and social norms. Interventions should focus on building self-efficacy, addressing stressors, and recognizing the social value of healthy behaviors, rather than just providing information.

Exercise-based cardiac rehabilitation improves health-related quality of life in a subset of patients, though evidence is heterogeneous.

While exercise-based cardiac rehab may not improve your quality of life in every case, it does so in the majority of patients. Focus on the proven mortality benefits, as QoL improvements are a positive bonus for many.

Adherence, not diet type, determines weight loss and cardiac risk reduction outcomes in popular diets.

Stop obsessing over which specific diet plan you follow. The data shows that whether you choose Atkins, Zone, Weight Watchers, or Ornish, the weight loss and heart health benefits are statistically identical if you stick with it. Your success depends entirely on how well you adhere to the plan you choose, not the plan's name. Focus on building a sustainable routine you can maintain for a year, rather than searching for a 'magic' diet.

Higher daily sitting time is associated with a dose-response increase in all-cause and cardiovascular disease mortality, independent of leisure-time physical activity levels.

Track your daily sitting time, not just your exercise minutes. If you sit for most of the day, your risk of early death from heart disease or other causes increases, even if you exercise regularly. Try to stand up and move briefly every hour to mitigate this risk.

Breaking up sedentary time with interruptions (breaks) is beneficially associated with lower waist circumference and lower C-reactive protein, independent of total sedentary time.

Don't just count total sitting hours; focus on breaking them up. Stand up or move for a minute every 30-60 minutes. This 'breaking up' of sitting time is linked to a smaller waist circumference and lower inflammation, regardless of how many total hours you sit.

Self-efficacy is the most consistent predictor of physical activity initiation and long-term maintenance in older adults.

Believe in your ability to exercise. Your confidence in your own capabilities is the biggest factor in whether you will start and stick with exercise. Build this confidence by starting with small, achievable goals, succeeding, and seeing others like you succeed.

Living in urban areas with accessible, walkable green spaces (parks, tree-lined streets) significantly increases five-year survival rates in senior citizens, independent of age, sex, socioeconomic status, and baseline functional status.

For seniors in cities, prioritize living near or having easy access to parks and tree-lined streets. This environmental factor is independently linked to living longer, likely by encouraging walking and physical activity. Urban planning that prioritizes walkable green infrastructure is a critical public health strategy for aging populations.

Simplified front-of-pack nutrition labels (signposting) increase consumer interest and perceived ease of use, but do not guarantee real-world dietary behavior change due to cognitive load, skepticism, and resistance to perceived coercion.

For food manufacturers and policymakers: Simplified front-of-pack labels (like traffic lights or color-coded GDAs) are preferred by consumers for their ease of use. However, to avoid resistance, these labels must be transparent and non-coercive. Complex back-of-pack tables are often ignored; simplification is key, but it must balance simplicity with enough detail to satisfy consumers' desire for full information.

Postoperative use of CPAP or NIPPV reduces respiratory complications in OSA patients who were using these devices preoperatively.

If you use a CPAP machine at home, bring it to the hospital. Your medical team will help you use it immediately after surgery to keep your airway open and prevent breathing problems.