Ranked by evidence
Weight loss: what actually works, graded by evidence
Losing fat comes down to a sustained calorie deficit; the strategies below differ in how well they help you keep one, keep your muscle and keep the weight off. Each page grades the evidence and says how to apply it. Weight-loss medication is outside the scope of this site: talk to a physician.
- Calorie deficit Strong evidence
Fat loss requires eating fewer calories than you burn for weeks to months; every diet that works does this, whatever it is called.
- High-protein diet while dieting Strong evidence
Eating more protein during a calorie deficit helps keep lean mass and gives a small extra fat loss compared with a standard-protein diet of the same calories.
- Low-carb vs low-fat diets Strong evidence
When calories and protein are similar, low-carbohydrate and low-fat diets produce about the same fat loss over a year or more.
- Resistance training while dieting Strong evidence
Lifting weights during a diet makes much more of the weight you lose come from fat instead of muscle, and it keeps or raises strength.
- Body recomposition (losing fat while gaining muscle) Moderate evidence
Losing fat and gaining muscle at the same time is possible, and it is most realistic for beginners, people returning after a break and people with more body fat.
- Cardio for weight loss Moderate evidence
Cardio helps fat loss, but at typical doses it produces only a couple of kilograms on its own; clinically meaningful loss takes high volumes (more than about 250 minutes a week) or a calorie deficit alongside it.
- Cutting ultra-processed food Moderate evidence
Two randomized feeding trials show that people eat more and lose less weight on ultra-processed diets, even when the menus are matched for nutrients or meet healthy-eating guidelines.
- Diet breaks and refeeds Moderate evidence
Planned periods at maintenance calories in the middle of a diet are at least as effective as dieting continuously and may make the diet easier to tolerate.
- Exercise and appetite (calorie compensation) Moderate evidence
A single workout does not make most people eat back the calories they burned, but over months many people partly compensate by eating more, so exercise alone usually produces less weight loss than the calories burned would predict.
- Intermittent fasting Moderate evidence
Intermittent fasting (5:2, alternate-day fasting or time-restricted eating) works for weight loss about as well as an ordinary calorie-controlled diet, but not better.
- Keeping weight off Moderate evidence
Most people regain much of the weight they lose, partly because appetite stays higher after weight loss.
- Rate of weight loss Moderate evidence
For people who lift, losing about 0.
- Self-monitoring (food logging and weighing) Moderate evidence
Tracking what you eat and weighing yourself regularly are consistently linked to more weight loss and less regain.
- Weight-loss plateau Moderate evidence
Almost every diet follows the same curve: early loss, a plateau within about 6 to 12 months, and then slow regain.
- Ketogenic diet for fat loss Limited evidence
A ketogenic diet (usually under 50 g of carbohydrate a day) causes fat loss only by creating a calorie deficit; tightly controlled metabolic-ward studies found no extra fat burning compared with a higher-carbohydrate diet at the same calories.
Weight-loss myths, checked
- Cardio before weights ruins your gains (exercise order matters) Moderate evidence
This one is partly true.
- Exercise alone is enough to lose weight Moderate evidence
Partly true.
- Calories don't matter, only food quality or hormones do Limited evidence
Calories matter: in tightly controlled feeding studies, eating more than you burn causes weight gain whatever the macronutrient mix, and isocaloric swaps of carbohydrate for fat barely change fat loss.
- Cardio kills your gains Limited evidence
Doing cardio alongside lifting does not, in general, cost you muscle or maximal strength.
- Cheat meals boost your metabolism Limited evidence
A big meal or a few days of overeating nudges energy expenditure and leptin up slightly, but the extra calories burned are far smaller than the extra calories eaten, so a cheat meal does not 'reset' metabolism or speed fat loss.
- Detox diets and juice cleanses flush out toxins and fat Limited evidence
There is no good evidence that detox diets remove toxins or fat.
- Eat every 3 hours to boost your metabolism Limited evidence
Eating small meals every 3 hours does not stoke your metabolism or speed up fat loss.
- Eating carbs at night makes you fat Limited evidence
For weight, what counts is total intake across the day, not the clock.
- Eating fat makes you fat Limited evidence
Dietary fat is not stored as body fat in some special way: at equal calories, low-fat and higher-fat diets lead to similar weight loss in long trials.
Metabolic adaptation is real: when you lose weight, your resting metabolism drops a bit more than the lost tissue explains.
- High reps with light weights tone, heavy weights bulk Limited evidence
There is no special "toning" rep range.
- Lifting weights makes women bulky Limited evidence
Women build muscle at about the same relative rate as men, but from a smaller starting point, so absolute gains are modest and slow.
- Muscle turns into fat when you stop training Limited evidence
Muscle cannot turn into fat: they are different tissues, and one does not convert into the other.
No food melts body fat.
- Spot reduction (crunches burn belly fat, leg work burns thigh fat) Limited evidence
Training a body part does not preferentially burn the fat on top of it.
- Sweating more means burning more fat Limited evidence
Sweat is water and electrolytes, not fat.
- You must stay in the fat-burning zone to lose fat Limited evidence
It is true that the share of energy coming from fat is highest at moderate intensities, but that does not decide how much body fat you lose.
- You should train abs every day Limited evidence
Daily ab training will not uncover a six-pack, and there is no evidence that abdominal muscles need daily work to grow.
Training that helps you lose fat
- Concurrent training (cardio plus weights) Strong evidence
Doing cardio alongside strength training does not meaningfully reduce muscle growth or maximal strength for most people.
- Daily protein intake Strong evidence
For people who lift, total daily protein matters: eating about 1.
- High-intensity interval training (HIIT) Strong evidence
HIIT alternates short hard efforts with recovery.
- Circuit training Moderate evidence
Circuit training moves from one resistance exercise to the next with little rest.
- Daily steps Moderate evidence
Walking more each day is linked to a much lower risk of death, with most of the benefit reached around 6,000–10,000 steps depending on age; 10,000 is not a magic number.
- High-intensity functional training (HIFT) Moderate evidence
High-intensity functional training mixes lifting, gymnastics and conditioning in fast, varied workouts.
- Sleep for training and recovery Moderate evidence
Losing sleep reliably hurts training performance, and in the lab even one sleepless night blunts muscle protein synthesis.
- Tabata (20 s on, 10 s off) Moderate evidence
The original Tabata protocol is eight all-out 20-second efforts with 10 seconds of rest, and in a small 1996 study it raised both aerobic and anaerobic capacity in four minutes of work.
- Fasted training (fasted cardio) Limited evidence
Training on an empty stomach burns more fat during the session, but that does not translate into more fat lost over weeks.
- Pilates Limited evidence
Pilates improves flexibility and gives a small boost to aerobic fitness, but it does not build strength or change body composition better than other exercise.
- Yoga Limited evidence
Most yoga is light-intensity activity.
- Zone 2 training Limited evidence
Easy, steady cardio clearly improves fitness and health, but the popular claim that "Zone 2" is a special, optimal intensity for building mitochondria and burning fat is not supported.