The study participants included 641 people in the United States, Canada and the United Kingdom, aged 65 to 91, who were overweight and were long-term (five years or more) survivors of breast, prostate and colorectal cancer. Some were assigned to a control group, while others were assigned to a 12-month intervention program that included telephone counseling, mailed materials promoting exercise, improved diet, and modest weight loss.

The study, published in the May 13 issue of the Journal of the American Medical Association, found that duration of strength-training exercise and endurance exercise minutes increased in the intervention group but stayed the same in the control group.

The researchers also found that the average intake of fruits and vegetables increased by 1.24 daily servings in the intervention group and by 0.13 daily servings in the control group. Average daily consumption of saturated fat decreased by 3.06 grams in the intervention group and by 1.07 grams in the control group. Members of the intervention group lost an average of 4.5 pounds, compared to 2.03 pounds in the control group.

At the start of the study, the average functional score for all the participants was 75.7 out of 100, which is comparable with the midpoint score for men and women aged 65 or older. By the end of the study, functional scores had declined an average of 2.15 points in the intervention group, compared to a decline of 4.84 points in the control group.

"Future studies should not only assess the effect [of exercise and diet intervention] on health and well-being, but also should address cost-related outcomes, especially given that the economic burden associated with functional decline and loss of independence is exceedingly high," according to study author Miriam C. Morey, of Duke University in Durham, N.C., and colleagues.

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