Are potatoes making you fat?

If so, you're not alone. In fact, potato chips were just named the number one culprit in gradual weight gain in a study conducted by researchers at Harvard Schools of Medicine and Public Health. Other food strongly associated with weight gain in the prospective longitudinal results reported in the June 23 issue of the New England Journal of Medicine included potatoes, sugar-sweetened beverages (ie, sodas, sweetened tea, lemonade, processed juices), unprocessed red meats (steak, hamburger, lamb, etc) and processed meats (hot dogs, cold cuts & sausage).

Four-year weight loss was most associated with intake of: yogurt, nuts, fruits, whole grains and vegetables (respectively, in order of greatest to least weight loss...yogurt was associated with the greatest amount of weight loss).

"'(These findings) reinforce the fact that even small changes can impact long-term weight maintenance,' noted Connie Diekman, MEd, RD, LD, a dietitian at Washington University in St. Louis and a past president of the American Dietetic Association.

Janet Kramer, RD, LD, a dietitian at University Hospitals Case Medical Center in Cleveland, saw few surprises in the breakdown of foods associated with weight gain and weight loss. 'It gives backbone to what dietitians have been saying for years,' she said in an interview.

The foods associated with weight loss fit with the emphasis on fruit, vegetables, and grains on the U.S. Department of Agriculture's plate graphic that recently replaced the food pyramid to guide food choices, Kramer pointed out.

But she cautioned against focusing too much on individual foods in the study rather than the overall picture of a healthy diet.

'There's no particular one food that is going to help a person lose weight," Kramer cautioned in the interview. 'There are a number of foods that contribute to weight gain, but overall it seems to support that calories in do make a difference.'

But identifying particular culprits in long-term weight gain may help with targeting interventions, noted Rena Wing, PhD, director of Brown University's Weight Control and Diabetes Research Center in Providence, R.I.

'We often tell people that if they want to avoid gaining weight they need to eat less and exercise more. That sounds easy but it's hard for people to do,' she said in an interview. "Being very specific and giving them specific targets to focus on may be easier for individuals."

The analysis pooled results from the Nurses' Health Study I and II and Health Professionals Follow-up Study for a total of 120,877 women and men free of chronic diseases and obesity at baseline who were followed for weight gain from 1986 to 2006, 1991 to 2003, and 1986 to 2006, respectively.

Weight gain averaged 3.35 lb across the cohorts during each four-year period, representing 2.4% of body weight, and added up to an average 16.8 lb over 20 years.

The researchers looked for links between changes in lifestyle factors and weight at four-year intervals after multivariable adjustment for age, baseline body mass index in each period, and all lifestyle factors simultaneously.

Other lifestyle factors also played a role in longer-term weight change (P<0.001).

Weight gain was linked to alcohol use (0.41 lb per drink per day), smoking cessation (new quitters gained 5.17 lb, former smokers gained 0.14 lb), and television watching (0.31 lb per hour per day).

Not surprisingly, physical activity was associated with 1.76 lb of weight loss over four years for the top versus bottom quintiles.

The researchers cautioned that the lifestyle changes seen in the cohorts were self-selected participants with the possibility of residual confounding and even reverse causality if those who were gaining weight shifted to healthier foods.

Although the three cohorts largely comprised white, well-educated American adults, the similarity in findings across the cohorts support similar effects in other populations, Mozaffarian's group noted."


Source: "Potato Chips a Top Culprit in Gradual Weight Gain"
By Crystal Phend, Senior Staff Writer, MedPage Today
Published: June 22, 2011