Intended for healthcare professionals


Exercise and diet reduce risk of diabetes, US study shows

BMJ 2001; 323 doi: (Published 18 August 2001) Cite this as: BMJ 2001;323:359
  1. Fred Charatan
  1. Florida

    Patients vulnerable to type 2 diabetes can more than halve their risk of developing the disease by eating a low fat diet and taking half an hour of exercise a day, says new US research from the National Institutes of Health.

    The study found that for patients at risk of type 2 diabetes diet and exercise were more effective than the drug metformin at preventing the disease. The findings come from the diabetes prevention programme, a clinical trial comparing diet and exercise with metformin treatment in preventing type 2 diabetes. It was conducted at 27 US medical centres and involved 3234 people with impaired glucose tolerance, a condition that often precedes diabetes.

    On the advice of the diabetes prevention programme's external data monitoring board, the trial ended a year early because the data had clearly answered the main research questions. The research has not been published in a journal, but a full report of the study is available on the National Institutes of Health website (

    Forty five per cent of the participants were from minority groups in whom type 2 diabetes is disproportionately prevalent, including African Americans, Hispanic Americans, Asian Americans, Pacific Islanders, and American Indians. The trial also recruited other high risk groups, including people aged 60 and above, women with a history of gestational diabetes, and people with a first degree relative with type 2 diabetes.

    Participants were randomly assigned to one of three groups. One made intensive lifestyle changes, with the aim of reducing weight by 7% through a low fat diet and exercising for 150 minutes a week. A second was treated twice daily with 850 mg metformin, a drug to treat type 2 diabetes. A third was given a placebo drug.

    The results showed that among people who make intensive lifestyle changes the risk of developing type 2 diabetes is reduced by 58% (compared with 31% among people who take metformin). Participants took on average 30 minutes of physical activity a day—usually walking or other moderately intensive exercise—and lost 5-7% of their body weight. Those treated with metformin reduced their risk of getting type 2 diabetes by 31%.

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