Can you lose fat from your belly alone?

Abdominal exercises are the most common advice for ‘getting rid of your belly’. The question has been studied several times, with abdominal exercises and with exercises for only one leg or only one arm. The results are fairly similar to each other.

What happened with abdominal exercises

In a small randomised trial, 24 adults who did not exercise did 7 abdominal exercises, 2 sets of 10, five days a week for 6 weeks. They ate as much as they needed to keep their weight stable. At the end, their weight, body fat percentage, belly fat and waist size had all stayed the same. Their abdominal muscle endurance, however, improved. The study was small and short, so the finding is of low certainty.

When you train only one leg or one arm

To see whether fat goes from the part of the body that is working, researchers have participants train only one side of the body and compare it with the other.

• One leg: 11 young people trained only their non-dominant leg for 12 weeks, with 960 to 1,200 repetitions on a leg press in each session. They lost 5.1% of their total fat. The fat, however, came off the arms (−10.2%) and the trunk (−6.9%), not the leg that was trained.
• One arm: 104 adults trained only their non-dominant arm for 12 weeks. MRI scans showed that the fat under the skin went down overall, with no difference between the trained arm and the other one. Skinfold measurements showed a small local reduction, in men only.

A 2022 analysis brought together 13 such studies with 1,158 people aged 14 to 71. The overall difference between the trained area and the other side was practically zero. Of the 37 comparisons, 17 leaned in favour of the trained area and 20 in favour of the other. Most of the studies were small and looked at arms and legs, not the belly, so the conclusion is of low certainty.

Two studies that found something different

In a 2023 trial of 16 men with overweight, over 10 weeks, those who exercised on a treadmill and also did abdominal exercises lost about 1.2 kg of fat from the trunk. Those who used only the treadmill, with the same total energy use, had no change there. The group doing abdominal exercises, however, lost less weight overall. A study of 14 people doing circuit training for 8 weeks also found less fat under the skin of the belly.

From all this we conclude that a local effect, if there is one, is small and uncertain. How much fat you lose overall matters far more.

Two kinds of belly fat

Belly fat is not all the same. Some lies under the skin, and this is the fat you can pinch with your fingers. Some lies deeper, around the organs, and is called visceral fat. The Greek National Dietary Guidelines for Adults (2014) say that people with more fat around the belly, the ‘apple’ shape, are more likely to have high blood pressure, diabetes, high cholesterol and metabolic syndrome.

For visceral fat, the studies found the following.

That aerobic exercise and weight loss reduce visceral fat is fairly certain. The comparison between aerobic exercise and weights is of low certainty. It also means that if you exercise and the scales do not move, something may still be changing inside your belly. For the scales, see the article on plateaus.

How to measure your waist

The UK's NICE recommends the waist-to-height ratio. You measure it like this:

1. Find the bottom of your ribs and the top of your hip bone.
2. Measure halfway between the two, roughly just above your belly button.
3. Breathe out naturally before you measure.
4. Divide your waist by your height, both in centimetres.

These cut-offs apply to men and women, to people of every ethnic background and to people with a lot of muscle, as long as body mass index (BMI) is under 35. In centimetres:

If the measurement shows increased risk, NICE recommends an assessment by a doctor.

You will also often see cut-offs of 94 and 102 cm for men and 80 and 88 cm for women, described as World Health Organization figures. The organisation's own report from 2008 says these numbers came from a Dutch sample, were given as an example and are not its recommendations. In Greece, in the EPIC study of 1994 to 1999, 39% of men had a waist of 102 cm or more and 55% of women a waist of 88 cm or more. These data are old.

What to do in practice

1. A calorie deficit. Fat is lost from the whole body when you eat less than you burn. See how many calories you need.
2. Aerobic exercise, such as brisk walking, cycling or swimming, at moderate intensity and for several weeks.
3. Weights and enough protein, so that you don't lose muscle along with fat. See how much protein you need.
4. Abdominal exercises, if you enjoy them. They strengthen the abdominal muscles, but they do not reduce fat there any more than anywhere else.
5. Measure your waist every few weeks, in the same way and at the same time of day.

When to take care

• Pregnancy: waist measurement does not apply.
• BMI of 35 or more: the NICE table does not apply. You need an assessment by a doctor.
• Under 18: a different method is used.
• Lower back pain, recent abdominal surgery, a hernia or separated abdominal muscles after giving birth: ask a doctor or physiotherapist before doing intense abdominal exercises.