BOSTON — A new study that combined three separate cohorts conducted by researchers at the Harvard School of Public Health found that such lifestyle factors as diet may influence long-term weight gain.
The study pooled data from 120,877 U.S. women and men who were free of chronic diseases and not obese at the beginning of the study, with follow-up periods from 1986 to 2006, 1991 to 2003, and 1986 to 2006. Patients were followed up at four-year intervals, researchers said.
At the conclusion of the study, participants gained an average of 3.35 lbs. during each four-year period, which corresponded to a weight gain of 16.8 lbs. over the 20-year period. The biggest food culprits that were strongly associated with weight gain were:
Potato chips (1.69 lbs.);
Potatoes (1.28 lbs.);
Sugar-sweetened beverages (1 lb.);
Unprocessed red meats (0.95 lbs.); and
Processed meats (0.93 lb.).
These weight gains were inversely associated with the intake of:
Vegetables (−0.22 lbs.);
Whole grains (−0.37 lbs.);
Fruits (−0.49 lbs.);
Nuts (−0.57 lbs.); and
Yogurt (−0.82 lbs.).
The study noted that other factors, including alcohol intake, watching television and sleeping for less than six or more than eight hours also contributed to long-term weight gain. Physical activity, however, attributed to a loss in weight.
“These findings underscore the importance of making wise food choices in preventing weight gain and obesity,” said Frank Hu, professor of nutrition and epidemiology at HSPH and senior author of the paper. “The idea that there are no ‘good’ or ‘bad’ foods is a myth that needs to be debunked.”
The study was published in the June 23 edition of the New England Journal of Medicine.