Participants in a recent study conducted by the New England Journal of Medicine gained an average of 3.35 lb. a year in the U.S. – a concern because the gain is so gradual it's sometimes hard to identify the causes.

Exploring patient behaviors more closely, Harvard researchers noted changes in lifestyle factors and a steady worsening in body mass index simultaneously contributed to the poor results.

Potato Based Foods & Sugar Drinks a Heavy Influence

Among the major correlations with the most weight gain we're those with a diet most commonly associated with potato chips (GI score of 54 – 74) who gains 1.69 lb, regular potatoes (baked, GI of 65) with 1.28lb, sugar based beverages (no GI) at 1.00 lbs, and unprocessed meats.

Foods with a strong reverse correlation (weight loss rather than weight gain) involved vegetables, log GI based whole grains (whole grain bread, GI score 40),  nuts, and yogurt (lowfat GI score 14).  [see Glycemic Index Chart for more scores]

Other factors not surprisingly involved:

• Physical activity (-1.76 lbs. for those engaged in regular activity)
• alcohol use (+ 0.41 lb per drink per day)
• smoking (+5.17 lb for new quitters)
• sleep (weight gain associated with those with < 6 hours or  > 8 hours of sleep a day)
• Television watching (+0.31 per 1 hour watched per day)

Glycemic Index and Dietary Choices Matter

Dietary and lifestyle choices can have a huge impact on normalizing weight and managing a healthy metabolism.  Diets high in the glycemic index and that feature low glycemic foods (see our glycemic index chart for more details) provide powerful advantages.  Other related diets like the south beach diet plan also perform well.).

While the observations noted in the New England Journal study aren't revolutionary, they confirm the premise of a managed diet and correlate strongly with the benefits gained when adopting a low glycemic index diet.  It's interesting to see weighted averages correlated by activity too!