How dangerous is belly fat?
A large amount of belly fat increases the risk of cardiovascular disease, gallstones and fatty liver, even when no other metabolic problems are present. Eating a Mediterranean diet and exercising for two hours a week is the best-evidenced approach to tackling that fat.
Not all belly fat is equally dangerous. The deep fat surrounding your organs -- visceral fat -- is the problem. A Chinese cohort study of more than 8,000 people over nine years showed that people with a lot of belly fat had a 75 to 87 percent higher chance of cardiovascular disease1. Notably, the risk was highest in people who had a lot of belly fat but none of the classic metabolic problems such as insulin resistance. Belly fat is therefore already a risk factor in its own right2.
The risks beyond the heart are also substantial. In an American study of more than 5,000 people, those with the most belly fat had more than three times the chance of developing gallstones3. Because this was a snapshot study, cause and effect have not been proven, but the difference is strikingly large. Low muscle mass combined with a lot of belly fat gave almost four times the chance of a fatty liver4. Building muscle therefore appears to be independently protective, separate from weight loss.
How much deep belly fat you have even leaves traces in your blood. A study of nearly 17,000 people involving tens of millions of protein measurements identified a recognisable pattern in blood proteins5. Several authors worked for the company behind the measurement technology, which may colour the interpretation. In practice this method is not yet in use, but it shows how wide-ranging the effects of belly fat are.
Good news: belly fat is very responsive to lifestyle changes. The combination of a Mediterranean diet, rich in legumes and plant-based foods, and around two hours of exercise per week significantly reduced deep belly fat after 12 weeks in people over 50 with a high cardiac risk6. Exercise or diet alone did not have this effect. The combination was crucial.
Considering medication? The drug liraglutide, comparable to the better-known semaglutide, reduced deep belly fat by an average of 12.5 percent over 36 weeks, compared with 1.6 percent in the placebo group7. However, nearly half of the users experienced gastrointestinal complaints. In addition, the study was funded by the manufacturer Novo Nordisk, which may cast a positive light on the results.
All claims are based on cohort studies, cross-sectional studies or small-scale RCTs. No large randomised long-term studies are available. Potential conflicts of interest play a role in two studies: one was funded by the drug manufacturer, and in another the authors worked for the company behind the technology used.