Multiple clinical studies have shown low glycemic index (GI), high protein foods can improve hunger management and help prevent energy dips, and meal plans based on these foods can lead to a leaner body composition (promoting fat loss while maintaining lean muscles during weight loss). Plus, in the case of diabetes, low GI diets may be better for improving diabetes control.
Most recently, a 2012 study in the New England Journal of Medicine concluded that people who followed a low GI, high protein meal plan for weight maintenance were more successful at keeping their lost weight off long term than those that followed higher GI and lower protein diets.
What does low GI mean? When you eat foods that contain carbohydrates – sugars and starches – your blood sugar (glucose) will rise as that carbohydrate is digested and absorbed. Studies have shown that the rate and degree of that rise in blood sugar varies considerably across foods. High GI foods release their carbs rapidly, producing a bigger spike in blood glucose and subsequently insulin levels. Low GI foods release their glucose more slowly. As a result, insulin levels also rise less, and this is part of a cascade of differences that favor low GI meal plans from a health perspective. Unfortunately, the precise GI value of a food isn’t something that’s as readily available as other nutrient information, like calories or fiber. Instead it requires clinical testing to determine the exact GI value of a particular food.
Fortunately, however, you can use these four simple rules to help you make decisions about GI:
1. – GI only applies to foods that contain carbohydrate. Oils, nuts, and most meats do not have enough carbohydrate to generate a GI.
2. – The more a carb is refined or processed, the higher the GI. Smooth, spongy white bread is more heavily processed than dense, chunky whole grain bread. The white bread probably has a higher GI.
3. – The more a carb is cooked, the higher the GI. Mushy pasta or rice will be broken down and converted to blood glucose more quickly than the same pasta or rice prepared al dente. The mushy stuff has a higher GI. Apple sauce (even with no sugar added) will have a higher GI than a raw apple.
4. – The riper a fruit, the higher the GI. An over-ripe apple, banana, or cantaloupe actually smells sweet, doesn’t it? Nature has already started the process of breaking down the carbs, which is work that your body doesn’t have to do. Carbs from ripe fruit are converted into blood glucose faster, resulting in a higher GI.
Meghan Nichols, R.D., is a registered dietician and part of the Research and Development team at Nutrisystem. Ms. Nichols draws from evidence-based best practices, as well as her practical know-how, to deliver positive nutrition communications that dieters can use to ensure weight loss success