You may not realize it, but your bagel and glass of soda have doubled in size over the past 20 years – most foods have. This increase in serving size has gone largely unnoticed, so has the extra 200 to 300 calories that accompany it.

Eventually, you may feel those extra calories sneaking up on you if you don’t increase your activity. Consuming those extra calories can mean 20 to 30 pounds in weight gain over a single year. This increase in portion sizes has likely contributed to the increase in our waistlines and obesity in our society, as a whole.

Research shows that the larger the portion, the more people tend to eat. Given a one-ounce, single-serving bag of potato chips, a person generally stops eating when the bag is empty. Give that same person a seven-ounce bag of chips, and he or she will likely eat more than one serving – it’s all about packaging.

Don't get me wrong, it’s OK to eat a large amount of one food or have a big meal – just be sure to balance it out by eating fewer calories at subsequent meals. The problem is, many of us have a difficult time striking that balance because our image of portion size is skewed. We call this “portion distortion.”  To avoid it, we must come to realize the true meaning of a single portion.

Servings vs. Portions

A serving is a recommended amount of food. A portion is what you serve yourself - it is often larger than a serving. For example, a serving of cooked pasta is ½ cup. But the portion that you put on your plate may measure 3 cups. That equals six servings. (Remember: it is fine to eat more than one serving at a meal, as long as you stay within your daily limits for each food group.) For more information on the number of suggested servings for each food group, go to the MyPyramid Web site at: www.mypyramid.gov.

Portions by Measure & Weight

When in doubt, measure it. You may be surprised by the results. If you don’t know what ½ cup of cooked rice looks like, measure it. Then put it on a plate or in a bowl to see how much space it takes. For drinks, measure 8 ounces of liquid, then pour it into a drinking glass to see what a suggested serving looks like.

More Tips:

• Read food labels. Many foods come in packages that contain more than one serving. Read the Nutrition Facts Label to find out how many servings are in the package and what counts as a single serving.

• Use smaller plates, bowls, glasses and mugs. Studies have shown that if you use a smaller plate, you will feel content and satisfied on 40 percent less food.

• Leave serving dishes off the table. This makes it harder to reach for second helpings.

• Focus on the meal. If you eat while you do other things, such as reading or watching TV, you may forget to keep an eye on portions.

• Eat slowly. You can eat a lot in a short time if you gulp down food.

To learn more about “portion distortion” and how portion sizes have changed over the last 20 years, visit http://hp2010.nhlbihin.net/portion.