Researchers who set out to determine which works best in reducing the risk of diabetes - exercise or a healthier diet - have found that both work equally well.
The US team thought that exercise would produce greater benefits than opting for a lower calorie diet. However both were found to provide beneficial health improvements.
The study involved 50-60 year olds, all with a body mass index of between 23 and 30. A BMI of up to 24.9 is considered normal weight, while a BMI of 25 to 29.9 is considered overweight. Thirty or higher is then classed as obese.
The participants were divided into three groups - an exercise group, a diet group and a control group. These groups were then monitored for one year.
Each person had their insulin action and glucose tolerance - both markers for diabetes - evaluated at the start and the end of the study. The participants' weight, body composition and energy intake were also measured throughout the 12 months.
The participants in the diet group met with a dietician on a weekly basis, who helped them to develop individual menu plans. They were advised to reduce portion sizes and replace high calorie foods with lower calorie choices.
The goal was to reduce their calorie consumption by 16% in the first three months and by 20% during the next nine months.
The goal of the exercise group meanwhile was to burn 16% more calories for the first three months, increasing to 20% during the next nine months. This group met with an exercise trainer every week and had open access to a fitness centre. To meet their goal, they exercised for between 60 and 90 minutes every day.
"As they got fit, the treadmill could be speeded up. They could exercise on a steeper grade and they could burn more calories. All of them learned very quickly the most efficient way to burn more calories was through cardio. If they pushed themselves, the numbers add up quickly", said lead researcher, Dr Edward Weiss of St Louis University.
He pointed out that while those in the control group could request general advice on eating healthily and could avail of free passes to a yoga class, few did.
By the end of the study, those in the exercise and diet groups had lost weight and seen an improvement in their glucose tolerance and insulin levels. These improvements were roughly the same between the two groups.
Those in the control group however did not lose weight and did not see any changes in their glucose tolerance or insulin levels.
"We thought exercise probably would produce greater benefits. But both provide profound benefits to reduce the risk of diabetes. Both those who restrict calories and those who exercise benefit from weight loss", Dr Weiss said.
The next step, he added, is to see how exercising and dieting at the same time affect the risk of diabetes.
"We don't know if the combination is going to provide greater benefits."
Details of these findings are published in the American Journal of Clinical Nutrition.
are there any other symptons,apart from taking blood,to show if your sugar levels are up.