Conclusion: A combination of dietary and non-dietary lifestyle modifications, begun in midlife or later in relatively healthy women, could have prevented at least half of the cases of type 2 diabetes in this cohort study of U.S. women.

Results: The 24-year risk of diabetes was 9.6% under no intervention and 4.3% when all interventions were imposed (55% lower risk [95% confidence interval = 47 to 63%]).
The most effective interventions were:
• weight loss (24% lower risk)
• physical activity (19%)
• moderate alcohol use (19%)
Overweight/obese women would benefit the most, with 10.8% point reduction in 24-year risk of diabetes. The validity of these estimates relies on the absence of unmeasured confounding, measurement error, and model misspecification.

Methods: Using data from the Nurses’ Health Study, we followed 76,402 women from 1984 to 2008.
We estimated the risk of type 2 diabetes under eight hypothetical interventions:
• quitting smoking
• losing weight by 5% every 2 years if overweight/obese
• exercising at least 30 minutes a day
• eating less than three servings a week of red meat
• eating at least two servings a day of whole grain
• drinking two or more cups of coffee a day
• drinking five or more grams of alcohol a day
• drinking less than one serving of soda a week

Background: Randomized trials have examined short-term effects of lifestyle interventions for diabetes prevention only among high-risk individuals. Prospective studies have examined the associations between lifestyle factors and diabetes in healthy populations but have not characterized the intervention. We estimated the long-term effects of hypothetical lifestyle interventions on diabetes in a prospective study of healthy women, using the parametric g-formula.

Ref: Danaei, Goodarz; Pan, An; Hu, Frank B.; Hernán, Miguel A. EPIDEMIOLOGY, 20131044-3983