|Emma McGowan NatureCity author & contributor|
A recent study suggests that changing the types of protein and carbohydrate-rich foods that people eat may have a significant effect on weight loss over the long term.
Participants in the study included 120,784 men and women who took part in three different long-term studies of U.S. health professionals. The researchers looked at the association between 4 year changes in consumption of protein foods, glycemic load (GL) and weight changed. They found that diets with a high GL — which usually contain a lot of starches, white bread, and potatoes — were associated with more weight gain over time than diets with a low GL.
The researchers then looked into the relationship between changes in GL and the effect on the relationship between major protein-rich foods and long-term weight gain. They found that changes in consumption of red meat and processed meat were most strongly associated with weight gain. Increased consumption of yogurt, seafood, skinless chicken, and nuts was associated with weight loss.
The researchers also noted that increased consumption of dairy products — including full-fat cheese, whole milk, and low-fat milk — did not seem to have an effect on either weight gain or loss. Therefore, the fat content of dairy products did not seem to have a large impact on weight gain. Interestingly, they did find that low-fat dairy consumption was associated with consumption of more carbohydrates, which can lead to weight gain. They attribute this to compensating for the lower calories by increasing carb intake.
They also found that increases in consumption of protein-rich foods that are associated with weight gain (such as red meat) were usually coupled with an increased dietary GL. This was usually the result of concurrent increased consumption of low quality carbohydrates such as white bread. However, when these protein-rich foods were consumed together with foods that had a lower GL, such as vegetables, participants gained less weight.
Finally, the researchers found that consuming fish, nuts, and other foods associated with weight loss along with a lower GL diet enhanced weight loss. Consuming them along with a higher GL diet decreased weight loss.
Researchers from the Tufts University and the Harvard School of Public Health conducted the study. It was published online ahead of print on April 8, 2015, in the American Society for Nutrition.