Protein has become a buzzword in health circles, and is generally thought of as a must-eat to prevent weight gain.
Sugars and refined grains, on the other hand, have become the dietary bad guys, known to trigger a rapid rise in blood sugar and insulin release that leads to fat storage.
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But what exactly is the link between protein, carbohydrates and weight?
the American Journal of Clinical Nutrition
examined how different protein foods are interchanged with carbohydrates, and how these interactions relate to weight gain.
Using data from three long-term studies among 120,000 men and women, the researchers discovered changes in carbohydrate amount and quality, and some specific protein foods, were associated with long-term weight gain. Alternatively, other protein foods were associated with weight loss.
Carbohydrate quality was measured using glycaemic load
(GL) and the glycaemic index
(GI), both indicators of a foods impact on blood sugar levels. The researchers believe that attention to the types of protein and carbohydrate foods eaten is crucial for long-term weight maintenance.
Eat this, not that
The study highlights the fact that among the different types of protein and carbohydrate foods we choose to eat every day, there are better and worse choices.
While it is wise to avoid labelling foods as good or bad, there are certainly some foods you should try to eat more of, and some to eat less of if your goal is to lose weight (or prevent gaining it).
Foods strongly associated with weight loss included plain or artificially sweetened yoghurt, seafood, skinless chicken, nuts, legumes and eggs.
Foods strongly associated with weight gain included hamburgers (both normal and lean varieties) hot dogs, pork, bacon, beef, lamb, chicken with skin, and regular cheese
The fat content of milk had minimal impact on weight change.
Moderate your portion sizes of starchy carbohydrate foods, and choose the less processed, low GI varieties such as oats, wholegrain breads and water rich vegetables.
Diets with a higher GL or higher GI were associated with weight gain over time. Examples of foods and drinks high in refined carbohydrates and sugars include white breads, white rice, processed breakfast cereals, soft drinks and fruit juice.
Eating processed carbohydrate foods that course rapid rises in blood glucose levels may induce less fullness and larger activation of reward and craving areas of the brain, resulting in overconsumption and weight gain.
Carbs & protein together
When combined, high GI foods both reduced the weight reducing potential of healthy protein foods, and further increased the weight increasing potential of lesser quality proteins. For example, eating pork with white bread might further augment their impact on weight gain.
Focusing on the types and quality of protein and carbohydrate rich foods, and their combinations, may be just as important as total kilojoule intake for weight control