The amount of food that you eat from the food groups can impact both your weight and blood glucose level. For instance, eating too much food from any food group is likely to cause weight gain. This weight gain can lead to higher blood glucose levels. Eating too much from the starch and starchy vegetables group, the fruit group, or the milk and yogurt group will cause your blood glucose levels to rise if you have diabetes. But how much food is too much, and what is a portion or serving size?

We sometimes think of what we put on our plate as a portion and a serving. While what we put on our plate may be considered a portion, it usually isn’t a serving in the way that dietitians think of servings. To care for yourself and your diet, you will need to begin thinking like a dietitian, and recognize that portions and servings are different.

Since portion sizes can vary from person to person, they are not a good measure of how much you should eat in one day. Serving sizes, however, are more strictly defined and do not vary from person to person. The American Dietetic Association and the American Diabetes Association have set serving sizes for foods in the various food groups. These serving sizes make it easier to identify how many calories, and how much carbohydrate, fat, and protein are in various foods.

It is important to remember that serving sizes may not be the same as the serving sizes listed on Nutrition Facts labels. Companies that make food products, for the most part, are allowed to decide what the serving size on their product should be. This serving size is often based on how much an average person would eat.

For instance, a Nutrition Facts label on a package of bread might list one serving as two slices of bread with 110 calories and 21 grams of carbohydrate. However, one serving from the starch group is defined by the American Dietetic Association and the American Diabetes Association as one slice of bread with about 80 calories and 15 grams of carbohydrate.

Serving sizes on Nutrition Facts labels vary depending on the product and the company that makes it. For this reason, it is always important to look at the calories and macronutrients as well as the serving sizes listed on the Nutrition Facts labels.

In the Nutrition Facts Label to the left, the serving size is 1 cup with 31 grams of carbohydrate. This would be two servings from the starch group or two carbohydrate units.

Don’t forget that if you eat more than one of the servings listed on the Nutrition Facts label, you should multiply the information by the additional number of servings you had. For example, if you had two servings of food, you should multiply the total number of carbohydrates by two to know how many calories and nutrients you actually had. In the same manner, you should divide by two if you only had half of the listed serving size.