If you've gained weight as an adult, blame it on potatoes - chips, fries and other potato dishes seem to be the foods most directly responsible for the pound per year the average adult gains.
That news comes from a Harvard School of Public Health Study that examined the diet and lifestyle factors that appear most related to long-term weight gain. The researchers reviewed three separate studies that included data from nearly 121,000 men and women who were followed from 12 to 20 years.
None of the participants were obese or suffered from any chronic disease when they joined the studies. The researchers assessed changes in consumption of specific foods and drinks, physical activity, TV time and time spent sleeping to help identify what contributes most to weight gain. All told, the researchers found that diet was the primary culprit and that the foods linked to the greatest weight gain were potato chips, other potato-based foods, sugar sweetened beverages, and unprocessed and processed meats. Increased consumption of some foods (vegetables, whole grains, fruits, nuts and yogurt) were linked to less weight gain.
This is another example of how specific foods that rank high on the glycemic index can contribute to weight gain. The glycemic index ranks carbohydrates on the basis of how quickly they raise your blood sugar. Rapid elevations in blood glucose set in motion a series of physiologic changes that induce the body to store calories as fat. Foods scoring higher than 60 (on a scale of 100) are considered high glycemic index foods. These include potatoes as well as most pastries and snack foods, most bread (both white and whole wheat), raisins and watermelon. Regular consumption of high glycemic index foods increases your risk of developing insulin resistance, an underlying cause of obesity, high cholesterol and adult-onset diabetes. In that respect, high-glycemic-index foods - including potatoes - can be considered "bad carbs."