Exercise can reach the belly fat that matters, and liposuction can’t

Key takeaways

• In a 2004 study, liposuction removed about a fifth of the body fat of 15 women with obesity, yet their blood sugar, insulin action, blood pressure and blood fats didn’t improve¹².
• Adults who did ab exercises five days a week for six weeks got better at curl-ups, but their belly fat didn’t change significantly, and a review of 13 studies found no sign that working one body part burns the fat over it⁵⁶.
• In studies where body weight held steady, exercise still cut visceral fat, the deep fat around the organs, by about 6%, while diet cut it by about 1%, a review of 117 studies found¹¹.
• In a Mayo Clinic experiment, two weeks of four-hour nights raised visceral fat 11% compared with normal sleep, even though weight rose only about a pound¹⁴.
• The Federal Trade Commission has charged sellers of electronic ab belts and a belly-fat supplement with deceptive claims; one belt seller agreed to pay $7 million in refunds⁷⁸⁹.

In 2004, a team led by Samuel Klein at Washington University in St. Louis tested an idea many people hope is true². If belly fat is the problem, why not simply take it out?

The researchers studied 15 women with obesity, 7 of whom had type 2 diabetes¹. Each had large-volume liposuction of the abdomen¹. Surgeons removed an average of 9.1 kilograms of fat in one group and 10.5 in the other, about 20 and 23 pounds by our math¹. That was close to a fifth of each woman’s total body fat¹².

Ten to 12 weeks later, the team repeated its detailed tests¹. Insulin worked no better in muscle, liver or fat tissue. Blood pressure, blood sugar, blood fats and markers of inflammation hadn’t improved¹.

The women had far less fat under their belly skin. Their metabolism looked the same¹².

The fat that matters most sits deeper than the surgery reached. Below, we look at what it is, how to track it and what shrinks it.

The fat you can pinch isn’t the fat that raises risk

Belly fat comes in layers. Subcutaneous fat lies just under the skin, and it’s the part you can pinch. It’s also what the liposuction study removed: the surgery cut the volume of fat under the belly skin by 44% in women without diabetes and 28% in women with it¹.

Visceral fat sits deeper, inside the abdomen around the organs³. Fat can also collect where it doesn’t belong, such as in the liver and around the heart. Researchers call this ectopic fat³.

In 2019, an international working group on visceral obesity published a position statement drawing on about three decades of studies that measured fat with CT or MRI scans³. Visceral fat was repeatedly tied to heart disease, metabolic disease and death, and fat in the liver and around the heart may add to artery disease³.

The group urged public health messages to target visceral and ectopic fat, not just body weight³.

That helps explain the liposuction result. As Klein explained when the study came out, the surgery takes out entire fat cells from the layer under the skin². The cells left behind stay the same size, and fat tucked into muscle and the liver stays put².

The researchers concluded that the health payoff of weight loss seems to require burning more energy than you take in, not just carrying less fat¹². Liposuction can reshape a waistline. In this study, it didn’t change the numbers that track with heart and diabetes risk¹.

A tape measure tells you more than the scale

You can’t see visceral fat in a mirror. Most of what’s known about it comes from CT and MRI scans, and the 2019 working group called for simpler tools that clinics can use³.

For now, your waist is the practical stand-in. In 2020, the same international group published a consensus statement urging clinicians to measure waist size routinely at checkups, as a “vital sign”⁴.

Their reasoning: waist size adds information about the risk of illness and death beyond BMI, yet it’s rarely measured⁴. They called a shrinking waist a key treatment target for both men and women⁴.

They also named gaps: cutoffs by age, sex and ethnicity still need work, and clinicians need training to measure consistently⁴.

Our article on metabolic syndrome shows the clinic method step by step and lists the U.S. waist cutoffs. A companion article on the limits of BMI covers waist-to-height ratio, another quick check.

At home, our suggestion is simple. Measure at the same spot, at the same time of day, every month or two, and watch the trend rather than any single reading.

If tracking your body feeds anxiety, restriction or old struggles with food, skip the tape; the consensus group wants clinicians to measure waists at checkups anyway⁴. The National Alliance for Eating Disorders runs a weekday helpline staffed by licensed therapists at 1-866-662-1235. In a crisis, call or text 988.

Six weeks of ab exercises built endurance, not a flatter belly

The belief that you can burn fat from one spot by working the muscle beneath it has a name: spot reduction.

A 2011 trial put it to a direct test⁵. Researchers randomly assigned 24 healthy, inactive adults ages 18 to 40 to an ab routine or to no exercise⁵. The routine had seven abdominal exercises, two sets of 10 each, five days a week for six weeks⁵. Everyone kept a steady diet⁵.

The exercisers improved: after six weeks they could do 47 curl-ups, versus 32 in the comparison group⁵.

But body weight, body fat percentage, belly-region fat on a DXA scan, waist size and belly skinfolds didn’t change significantly⁵.

Larger reviews agree. A 2022 meta-analysis, a study that pools results from earlier studies, combined 13 studies with 1,158 people ages 14 to 71⁶. Across 37 comparisons of a trained body part with an untrained one, 17 favored the trained side and 20 favored the untrained side⁶. The overall effect was essentially zero⁶.

The authors blamed the myth’s staying power on wishful thinking and marketing⁶. Core strength is worth building. It just doesn’t melt the fat on top.

Ab belts and belly-fat pills drew federal charges

Where a myth lives, a product follows. In 2002, the Federal Trade Commission (FTC) charged the marketers of three top-selling electronic ab belts, AB Energizer, AbTronic and Fast Abs, whose infomercials each aired well over 1,000 times⁷.

The FTC charged that the belts’ promises were false: fat and inch loss, “six-pack” abs, and results equal to or better than sit-ups⁷.

FTC Chairman Timothy Muris summed up the agency’s view: there are “no magic pills, potions, or pulsators”⁷.

Another belt, Ab Force, fought the charges. From 2004 to 2006, an administrative judge, the full Commission and a federal appeals court all found its fat-loss and defined-abs claims deceptive⁸. In a settlement announced in January 2009, its marketers agreed to pay $7 million for consumer refunds; more than 700,000 belts and accessories had been sold⁸.

Pills have followed the same script. In 2015, the FTC charged the marketers of Amberen, a supplement sold to women over 40 with claims that it would cut belly fat and boost metabolism around menopause⁹. It brought in nearly $65 million from 2010 to 2013⁹.

The FTC said the “clinically proven” study behind the product used a double dose and never measured weight loss, and a later study found no significant difference from a control group⁹. The marketers settled with the FTC in 2016⁹.

Exercise shrinks the deep fat, even when the scale stalls

The hopeful flip side: the fat that matters most responds to movement.

A 2013 meta-analysis in PLoS One pooled 15 studies of 852 adults with overweight, all measuring visceral fat by CT scan and none restricting calories¹⁰. Exercise reduced visceral fat by a moderate amount¹⁰.

Aerobic training at moderate or high intensity looked most promising¹⁰. Without a diet, the authors estimated, it could cut visceral fat area on a CT image by more than 30 square centimeters in women and 40 in men, in programs as short as 12 weeks¹⁰.

A larger 2016 review in Obesity Reviews pooled 117 studies with 4,815 people and compared exercise with calorie-cutting diets¹¹. Diets produced more weight loss¹¹. Exercise trended toward a bigger drop in visceral fat, though that difference fell short of statistical significance¹¹.

The most striking finding came from studies where weight didn’t fall. There, exercise still cut visceral fat by about 6%, while diet cut it by about 1%¹¹. The authors suggested that body weight may be a poor yardstick for judging healthy changes¹¹.

A 2023 meta-analysis in the British Journal of Sports Medicine, of 40 randomized trials with 2,190 adults, found a dose effect¹². The more energy people burned through exercise each week, the more visceral fat they lost¹². The effects were small, and the authors said they were moderately confident in them¹².

Which kind works best? A network meta-analysis, which ranks options against one another, covered 84 trials with 4,836 people with overweight or obesity¹³. Aerobic exercise of at least moderate effort, strength training, the two combined, and high-intensity intervals all reduced visceral fat¹³.

Vigorous aerobic work and intervals ranked highest¹³. Strength training alone ranked lowest. It helped men and people under 40% body fat, but not women or people with more body fat¹³.

Lifting still earns its place; our article on resistance training covers its blood pressure and blood sugar benefits and how to start safely.

Food and sleep move the deep fat, too

Diet matters. In the 2023 review, cutting calories reduced visceral fat, and its overall effect looked larger than exercise’s¹². Unlike exercise, bigger calorie cuts didn’t bring bigger visceral losses, possibly because fewer diet trials were available¹².

In the 2016 review, the drop in visceral fat on a diet tracked closely with how much weight people lost¹¹. That fits the liposuction lesson: the benefit seems to come from using more energy than you take in².

This article doesn’t set calorie targets. If cutting back on food has ever pulled you toward restriction, the National Alliance for Eating Disorders helpline, 1-866-662-1235, can help you find support first.

Weight-loss medicines such as semaglutide fall outside this article’s ratings. Our article on preserving muscle with age covers what body scans showed about fat and lean tissue in a major semaglutide trial, and how to protect muscle on these drugs.

Sleep is the surprise. In a Mayo Clinic study published in 2022, 12 healthy adults without obesity spent two three-week inpatient stays in a research unit¹⁴. In one, they spent two weeks with four hours in bed a night; in the other, nine hours¹⁴. Food was freely available¹⁴.

Short sleep led people to eat more than 300 extra calories a day, while the energy they burned stayed about the same¹⁴. Weight rose only about a pound¹⁴.

But CT scans showed total belly fat up 9% and visceral fat up 11% compared with normal sleep¹⁴. Visceral fat kept rising during recovery nights, even as eating and weight fell¹⁴.

It’s one small study, so the finding is promising but early. Still, a bathroom scale would have missed the change entirely.

Midlife changes the body before the scale notices

Research backs up part of the common belief that bodies change around menopause. The Study of Women’s Health Across the Nation, known as SWAN, tracked body composition with DXA scans in 1,246 Black, Chinese, Japanese and white women¹⁵.

In a 2019 analysis, the pace of fat gain nearly doubled once the menopause transition began, from about 0.25 kilograms a year to about 0.45¹⁵. Lean mass, which had been inching up, started to fall¹⁵. These shifts continued until about two years after the final menstrual period, then leveled off¹⁵.

Body weight told a calmer story. It kept rising at the same steady pace, with no jump at the transition¹⁵. Over the transition, fat rose about 1.6 kilograms while lean mass fell slightly, so the scale hid a change in what the body was made of¹⁵.

Not everyone followed the pattern. Japanese women in the study showed no significant fat gain during the transition, and hormone therapy use didn’t predict the changes¹⁵.

This analysis measured whole-body fat, not where it settled, so it can’t by itself show fat moving to the belly¹⁵. A later article in this series on menopause covers fat distribution and treatment choices.

If you suspect stress, our article on the stress response explains why cortisol-control products overpromise.

The midsection plan

This is reassuring for anyone who trusts the body’s own systems. The fat that matters most isn’t removed by surgery or zapped by a belt. It responds to things you control: how you move, how you eat and how you sleep.

We built this plan from the studies above.

Step	What to do	What the research shows	Rating	What doesn’t work
Measure	Check your waist every month or two, same spot and time; our metabolic syndrome article has the method	Waist adds risk information beyond BMI4	Strong evidence	Judging belly fat by the scale alone1114
Move	Build up regular aerobic exercise; add harder efforts or intervals if your health allows	Cuts visceral fat even without weight loss; more exercise, more loss10111213	Strong evidence	Crunches to burn belly fat56
Lift	Add strength training for muscle, blood pressure and blood sugar	Ranked lowest for visceral fat; helped men and leaner people13	Promising but early	Ab belts sold as a sit-up substitute78
Eat	Make food changes you can keep, without crash diets	Calorie reduction lowers visceral fat, mostly through weight loss1112	Strong evidence	Supplements sold to target belly fat9
Sleep	Protect enough sleep most nights	Two weeks of four-hour nights raised visceral fat 11%14	Promising but early	Assuming steady weight means steady belly fat14

Bring your waist number to checkups along with your blood pressure and lab results. The 2020 consensus group wants clinicians to record it routinely⁴.

How strong is the evidence?

Claim	Evidence level	What the research shows
Visceral fat tracks with heart and metabolic disease	Strong evidence	About 30 years of CT and MRI studies3
Liposuction improves metabolic health	Evidence says no, or unsafe	No change in insulin action, blood pressure, sugar or blood fats1
Ab exercises burn belly fat	Evidence says no, or unsafe	A six-week trial and a 13-study review found no spot reduction56
Aerobic exercise reduces visceral fat without dieting	Strong evidence	Several meta-analyses10111213
Cutting calories reduces visceral fat	Strong evidence	Two meta-analyses; tied closely to weight loss1112
Strength training alone reduces visceral fat	Promising but early	Helped men and leaner people, not women or those with more body fat13
Short sleep adds visceral fat	Promising but early	One small, tightly controlled study14
Supplements sold to shrink belly fat	Not enough evidence	In one FTC case, the study behind the product didn’t measure weight loss9

Questions readers ask

The bottom line

Belly fat isn’t one thing. The deep fat around the organs tracks with diabetes and heart disease. Removing the outer layer by surgery didn’t help metabolism, ab exercises didn’t shrink belly fat, and electric belts drew federal charges.

What works is less glamorous and more in your hands. Regular aerobic exercise trims visceral fat even when the scale won’t move, eating changes help mostly through weight loss, and short sleep may push the deep fat up. Track your waist, not just your weight.

Related reading

• Body-fat scales can miss by several pounds, and even lab scans only estimate
• Metabolic syndrome is just five numbers that together still predict trouble
• Weights once sent blood pressure past 400, but done right, lifting lowers it
• Short sleep blunts insulin and stokes appetite, and adding sleep cut calories
• The stress response saves you in minutes, and viral cortisol fixes misread it

Sources

1. Klein S, Fontana L, Young VL, Coggan AR, Kilo C, Patterson BW, Mohammed BS. “Absence of an Effect of Liposuction on Insulin Action and Risk Factors for Coronary Heart Disease.” New England Journal of Medicine, 2004 (University of Brescia record with abstract). expertise.unibs.it
2. Dryden J. “Liposuction won’t prevent diabetes, heart disease.” Washington University in St. Louis, The Source, June 30, 2004. source.washu.edu
3. Neeland IJ, Ross R, Després JP, et al. “Visceral and ectopic fat, atherosclerosis, and cardiometabolic disease: a position statement.” Lancet Diabetes & Endocrinology, 2019 (University of Padua record). research.unipd.it
4. Ross R, Neeland IJ, Yamashita S, et al. “Waist circumference as a vital sign in clinical practice: a Consensus Statement from the IAS and ICCR Working Group on Visceral Obesity.” Nature Reviews Endocrinology, 2020;16(3):177–189 (Vrije Universiteit Amsterdam record). research.vu.nl
5. Vispute SS, Smith JD, LeCheminant JD, Hurley KS. “The effect of abdominal exercise on abdominal fat.” Journal of Strength and Conditioning Research, 2011;25(9):2559–2564 (abstract via Nutrition Evidence database). nutrition-evidence.com
6. Researchers in Chile, Portugal, Spain and Brazil. “A proposed model to test the hypothesis of exercise-induced localized fat reduction (spot reduction), including a systematic review with meta-analysis.” Human Movement, 2022;23(3):1–14. doi.org
7. Federal Trade Commission. “FTC Charges Three Top-Selling Electronic Abdominal Exercise Belts with Making False Claims.” Press release, May 8, 2002. ftc.gov
8. Federal Trade Commission. “Marketers of Ab Force Weight Loss Device Agree to Pay $7 Million for Consumer Redress.” Press release, January 14, 2009. ftc.gov
9. Federal Trade Commission. “FTC Charges Marketers with Misleading Claims That Their Supplement Causes Weight Loss, Fat Loss, and Increased Metabolism in Women Over Forty.” Press release, May 12, 2015. ftc.gov
10. Vissers D, Hens W, Taeymans J, Baeyens J-P, Poortmans J, van Gaal L. “The effect of exercise on visceral adipose tissue in overweight adults: a systematic review and meta-analysis.” PLoS One, 2013;8(2):e56415 (PEDro record). search.pedro.org.au
11. Verheggen RJHM, Maessen MFH, Green DJ, Hermus ARMM, Hopman MTE, Thijssen DHJ. “A systematic review and meta-analysis on the effects of exercise training versus hypocaloric diet: distinct effects on body weight and visceral adipose tissue.” Obesity Reviews, 2016;17(8):664–690 (Liverpool John Moores University record). researchonline.ljmu.ac.uk
12. Recchia F, Leung CK, Yu AP, et al. “Dose–response effects of exercise and caloric restriction on visceral adiposity in overweight and obese adults: a systematic review and meta-analysis of randomised controlled trials.” British Journal of Sports Medicine, 2023;57(16):1035 (funded by the Research Grants Council of Hong Kong). pubmed.ncbi.nlm.nih.gov
13. Chen X, He H, Xie K, Zhang L, Cao C. “Effects of various exercise types on visceral adipose tissue in individuals with overweight and obesity: A systematic review and network meta-analysis of 84 randomized controlled trials.” Obesity Reviews, 2023, DOI 10.1111/obr.13666 (CiteDrive record). citedrive.com
14. Malloy T. “Lack of sleep increases unhealthy abdominal fat.” Mayo Clinic News Network, March 28, 2022 (on Covassin N, et al., Journal of the American College of Cardiology, 2022;79(13):1254–1265). newsnetwork.mayoclinic.org
15. Greendale GA, Sternfeld B, Huang M, et al. “Changes in body composition and weight during the menopause transition.” JCI Insight, 2019;4(5):e124865. insight.jci.org