Two Studies Cast Further Doubt on the Effectiveness of Low GI/GL Diets for Weight Loss

The Studies Provide Good News for Potato Lovers.

Feb 11, 2008, 00:00 ET from United States Potato Board

    DENVER, Feb. 11 /PRNewswire/ -- A study published in the September 2007
 issue of the American Journal of Clinical Nutrition provides further
 evidence that the glycemic index (GI) of a diet is not important; when it
 comes to weight loss it is calories that count. This study adds to the
 growing body of evidence supporting the health benefits of a diet rich in
 fruits and vegetables, including potatoes, according to the United States
 Potato Board.
     Researchers from Harvard and the State University of Rio de Janeiro in
 Brazil who worked independently from any food industry sponsors, sought to
 determine if a low GI diet would be more effective than a high GI diet for
 long-term weight loss in 203 overweight and obese women. Both diets
 included a mild energy restriction (i.e., 100-300 fewer calories per day)
 and had similar macronutrient distributions (i.e., carbohydrate, protein
 and fat); all that distinguished the two diets were the GIs of the foods.
 The high GI diet contained a hefty dose of potatoes and other commonly
 identified high GI foods (e.g., bananas, watermelon, rice and white bread)
 while the low GI diet contained large amounts of beans and other low GI
 foods (e.g., apples, pears, oats, and sweet potatoes). At the end of the
 18-month period both groups had lost weight and there were no significant
 differences in weight loss between the two groups.
     The results are timely for America's favorite vegetable, the potato,
 and the U.S. potato industry, which has been unfairly maligned by low GI
 diets. Far from a dietary villain, potatoes are a satiating and nutrient
 rich vegetable containing 45% of the recommended daily value (DV) of
 vitamin C, 18% DV of potassium*, and no fat, sodium, or cholesterol -- all
 for 110 calories per 5.3 ounce serving.
     Another study published last spring in the American Journal of Clinical
 Nutrition conducted by the Jean Mayer U.S. Department of Agriculture Human
 Nutrition Research Center on Aging at Tufts University (USDA HNRCA) also
 showed that the glycemic load of the diet doesn't matter as long as
 calories are reduced. In this study, 34 overweight, but otherwise healthy,
 men and women achieved and maintained similar weight and body fat losses
 after one year, whether they were on a low-glycemic-load or a
 high-glycemic-load diet. The reason? Both groups reduced their energy
 intake by 30%.
     According to Glenn Gasser, Associate Professor of Exercise Physiology
 at the University of Virginia, the results of these studies are not
 surprising. "If you want to lose weight reduce the number of calories you
 consume, not carbohydrates!" In a recent review published in the Journal of
 the American Dietetic Association, Gasser found that diets high in
 carbohydrates are almost universally associated with slimmer bodies and
 consuming a high-glycemic diet is not associated with higher body weights.
 "It is not the GI or GL that makes for healthier bodies, but the overall
 quality of a high-carb diet, which includes more fiber-rich and nutrient
 dense foods. Potatoes can certainly fit into this category."
     The United States Potato Board was established in 1971 by a group of
 potato growers to promote the benefits of eating potatoes. Recognized as an
 innovator in the producer marketing industry, the USPB was one of the first
 commodity groups to develop and use a nutrition label that was approved by
 the FDA. Based in Denver, CO, the USPB represents more than 4,000 potato
 growers and handlers across the country. For more information about the
 USPB and its programs, visit
     * with the skin

SOURCE United States Potato Board