Exercise can help people with large waistlines reduce their risk of developing type 2 diabetes, Finnish researchers said on Friday.
Type 2 diabetes, the more common form of the illness caused by an inability to make or properly use insulin, is linked to being overweight or obese.
But scientists from the National Public Health Institute in Helsinki found that people with large waistlines who exercise were less likely to suffer from type 2 diabetes than their less active counterparts.
"People who were obese were more likely to be diagnosed with glucose intolerance and type 2 diabetes but if they were physically active their risk was significantly lower," said Katja Borodulin, who headed the study.
Glucose intolerance is an early indication that glucose is not being processed efficiently in the body.
"The novelty value of our study is that we used waist-to-hip ratio which is a measure of abdominal obesity and not body mass index (BMI) which was used in previous studies," she added in an interview.
Diabetes affects about 194 million people worldwide. Experts say the number could rise to 333 million by 2025. The illness also increases the risk of heart disease, stroke, blindness, kidney damage and nerve disorders that can lead to foot ulceration and amputations.
Borodulin and her team studied the impact of exercise on 1,812 normal and overweight people in the study published in the journal Diabetic Medicine. They found that physically inactive people with large waistlines had a 5.5 times greater risk of suffering from diabetes than active people with small waists.
They added that 30 minutes of exercise five times a week could help people with large waists lower their odds of suffering the illness by 4.2 times.
A large waistline, high blood pressure, raised insulin levels, excess body weight and abnormal cholesterol levels are a cluster of signs of metabolic syndrome. If someone has three or more symptoms they have the syndrome and are at a higher risk of suffering from heart disease and stroke as well as diabetes.
Simon O'Neill, of the charity Diabetes UK, said the research showed that exercise reduces the risk of developing diabetes regardless of a person's waist size.
"Your waist should measure less than 31.5 inches for women, 37 inches for white and black men, and 35 inches for South Asian men. This can be achieved through a healthy diet, alongside regular physical activity," he said in a statement.