Carbohydrates are often blamed for adding in pounds, but a new study has found that pasta's low glycemic index can actually help lose weight.
Researchers from St. Michael's Hospital in Toronto, Canada, conducted a systemic review and meta-analysis of 30 randomized control trials of people who ate pasta as the main source of carbohydrate in their diet.
The study, which was published Tuesday, April 3, in British Medical Journal, analyzed data from almost 2,500 individuals.
Contrary to the common understanding about carbohydrates, pasta does not necessarily contribute to weight gain. It has a low glycemic index, which means that it causes a slight increase in the blood sugar level.
The participants of the study had an average consumption of 3.3 servings of cooked pasta per week, where one serving measures about 0.5 cups. For an average follow-up of 12 weeks, they lost about 0.5 kilograms.
"The study found that pasta didn't contribute to weight gain or increase in body fat. In fact analysis actually showed a small weight loss. So contrary to concerns, perhaps pasta can be part of a healthy diet such as a low GI diet," reported lead author Dr. John Sievenpiper, who is also a fellow at the hospital's Clinical Nutrition and Risk Modification Centre.
The researchers concluded that the weight loss effect of pasta can be generalized to other foods with low glycemic index. However, they suggest that future studies be conducted to determine if pasta will have the same effect when combined with other diets.
Low GI Foods
Foods with higher glycemic index are rapidly absorbed into the bloodstream, which then increases the blood sugar. The American Diabetes Association recommends combining high GI with low GI foods to achieve a balanced diet.
Examples of low GI foods include whole wheat, oatmeal, rice, barley, and root crops such as sweet potato, corn, legumes, and lentils. High GI foods include white bread or bagel, rice cakes, rice pasta, macaroni, and cheese. Not all fruits that are rich in fiber such as melon and pineapple belong to the low GI category.
Although the GI value identifies the type of carbohydrate present in food, the American Diabetes Association said it does not equate to the number of portions eaten. Weight gain or loss remains dependent on portion sizes, controlling blood sugar levels, and managing weight.
The study was sponsored by the Canadian Institutes of Health Research. Despite the promising effects of a low GI diet as presented in Dr. Sievenpiper's paper, experts said labeling foods based on its GI levels could be misleading to the public.
A paper by the International Carbohydrate Quality Consortium, published in the British Journal of Nutrition, concluded that putting GI levels in food labels will not be useful for three reasons.
"[GI] has poor accuracy and precision for labeling purposes. It does not vary in response to the amount of food consumed, and it is not congruent with national nutritional policies and guidelines," said lead author David Jenkins, who also serves as the chair of the ICQC.
The challenge now, according to the research authors, is to develop a tool that will translate the impact of GI values in current health recommendations.