How to lose belly fat: what works and what does not

• No spot reduction: belly fat comes off along with the rest of the body, often last.
• What works: a lasting calorie deficit, enough protein, strength training, sleep.
• How to measure: waist and waist-to-height ratio, not just the scale.
• How many weeks: the waist moves more slowly than you would like; look at 4-week averages.

Why you cannot burn belly fat on purpose

Body fat is released from the whole body, not from around the muscle you work. In a six-week trial (Vispute and colleagues) regular ab training did not reduce abdominal fat any more than the control. Ab work strengthens the muscle, which makes the stomach look better defined, but the fat layer goes with the calorie deficit. Where fat leaves first is decided by genetics, sex hormones and age.

How to lose belly fat, step by step

1. Calorie deficit: 10-20% below your daily calorie need. Our calculator works it out.
2. Protein: 1.8-2.4 g/kg a day, to keep muscle and stay full.
3. Strength training: 2-3 sessions a week built on big movements (squat, deadlift, press, row). Muscle stays while you lose fat; ab work is a bonus.
4. Movement through the day: steps, walking. Track the average and raise it gradually.
5. Sleep: at least 7 hours. In one small study (Nedeltcheva and colleagues), at the same calorie deficit short sleepers lost less fat and more lean mass.
6. Alcohol: it counts as calories too, and often goes unlogged. A pint of beer is about 215 kcal.

Example: for a 80 kg, 178 cm, 30-year-old, moderately active man our calculator gives a daily need of about 2,740 kcal and a fat-loss target of 2,330 kcal. For your own: calorie calculator; for the whole plan: weight loss, step by step.

How to measure belly fat: waist-to-height ratio

BMI does not show where your body stores fat. Waist circumference, and even better the waist-to-height ratio, track belly fat more closely. The simple rule: keep your waist under half your height (a ratio below 0.5). In the pooled analysis by Ashwell and colleagues, waist-to-height ratio predicted cardiometabolic risk better than BMI.

According to the WHO, increased risk starts above 94 cm for men and 80 cm for women, and substantially increased risk above 102 and 88 cm. To measure: halfway between the lowest rib and the top of the hip bone, at the end of a breath out, with a relaxed tape. Always at the same place and time. The body fat calculator estimates body fat percentage from your waist and neck, and the BMI calculator shows the healthy weight range for your height.

What does not work?

• Only ab exercises: crunches strengthen the abs, they do not take the fat off.
• “Fat burner” pills, belts, saunas: there is no reliable evidence they take fat off; a sauna just takes water.
• Zero carbs: on its own it does not burn fat better when calories are equal. Keto diet.
• Weighing daily: both the scale and the waist fluctuate; the weekly or monthly average counts.

How long does belly fat take to go?

Body weight and waist do not always move together: muscle grows and water fluctuates. If your weekly weight falls by 0.5-1%, the waist starts to shrink within a few weeks. Look at 4-week averages and do not rush: fast loss comes with muscle loss.