Changes in Specific Dietary Factors May Have Big Impact On Long-Term Weight Gain

In a series of three separate studies looking at how changes in multiple dietary and other lifestyle factors relate to long-term weight gain, Harvard School of Public Health (HSPH) researchers found that modest changes in specific foods and beverages, physical activity, TV-watching, and sleep duration were strongly linked with long-term weight gain. Changes in diet, in particular, had the strongest associations with differences in weight gain.

When relations of lifestyle changes with weight gain were evaluated, the findings were strikingly similar in all 3 studies.

For example, the foods associated with the greatest weight gain over the 20-year study period included potato chips (for each one increased daily serving, +1.69 lb more weight gain every 4 years), other potatoes (1.28 lb), sugar-sweetened beverages (1.00 lb), unprocessed meats (0.95 lb), and processed meats (0.93 lb). Of note, several foods associated with less weight gain when their consumption was actually increased, including vegetables (−0.22 lb), whole grains (−0.37 lb), fruits (−0.49 lb), nuts (−0.57 lb) and yogurt (−0.82 lb). Evaluating all changes in diet together, participants in the lower 20% of dietary changes gained nearly 4 lbs more each 4 years than those in the top 20% -- an amount equivalent to the average weight gain in the population overall.

For diet, focusing only on total calories may not be the most useful way to consume fewer calories than one expends, say the researchers. Other yardsticks, such as content of total fat, energy density, or sugars, could also be misleading. Rather, they found that eating more healthful foods and beverages -- focusing on overall dietary quality -- was most important.

The most useful dietary metrics for preventing long-term weight gain appeared to be:

• Focus on improving carbohydrate quality by eating less liquid sugars (e.g. soda) and other sweets, as well as fewer starches (e.g. potatoes) and refined grains (e.g. white bread, white rice, breakfast cereals low in fiber, other refined carbohydrates).
• Focus on eating more minimally processed foods (e.g. fruits, vegetables, whole grains, nuts, yogurt) and fewer highly processed foods (e.g. white breads, processed meats, sugary beverages).
• http://www.sciencedaily.com/releases/2011/06/110622224457.htm