Do food labels provide any useful information about glycemic index?
The standard nutrition facts panel helps only indirectly. It shows how many grams of sugar a food contains as well as how many carbohydrates. But not all carbohydrates are created equal. A spoonful of sugar is a carbohydrate. So is an apple. Obviously an apple is a healthier choice than a spoonful of sugar. An apple contains many nutrients. In addition, it has lots of fiber, which helps keep blood sugar levels from spiking too high. For that same reason, brown rice has a lower glycemic index than white rice. Most of us should consume about 25 grams of fiber a day. The current average for most Americans is far below that. So we have a long way to go. Fiber also helps lower bad cholesterol.
What about carbohydrates?
There’s a lot of debate about the healthiest ratio of carbohydrates, fat, and protein. I think a good rule of thumb is about 40% of the calories should come from carbohydrates, about 30% from fat, and around 30% from protein. Protein helps make meals more satiating, and that can help people lose weight or maintain a healthy weight. Protein also helps in maintaining the lean muscle mass during weight loss and does not raise the blood glucose levels as carbohydrates do. You still need at least 130 grams of carbohydrates or more per day. Both the total amount of carbohydrates and their type matter. As I said, it’s especially important that the carbohydrates you consume are as unrefined as possible.
How can food labels help?
First, look at the ingredient list on the food label to see that it contains whole wheat, whole oats, and other unrefined grains. The 2010 Dietary Guidelines recommend three servings of whole-grain foods a day. (A serving equals 16 grams of whole grains.) The Whole Grain Stamp that appears on many labels can be helpful. It indicates that a food contains at least 8 grams of whole grains per serving. A food that bears the label “100% Whole Grains” contains at least 16 grams. I usually tell my patients when you select your carbohydrates, try to remember VFW (vegetables, fruits and whole grains) and make your selection from them.
Other logos are appearing on foods to show that they meet certain health guidelines, such as the American Heart Association’s heart check. Are they also useful?
They offer a helpful shorthand evaluation. But I think consumers should still be careful to look at the nutrient facts panel and the ingredients on their own. For example, when you see "sugar free", it does not mean it is carbohydrate free. You still need to see how much carbohydrates and what type of carbohydrates. The American Heart Association checkmark evaluates saturated fat and sodium, for example, but it doesn’t consider how much sugar a food contains. And, of course, too much sugar in the diet can increase the risk of diabetes.