If you think that plate of spaghetti is much bigger than it was when you were a child, you're probably right: Portion size has increased dramatically over the past 20 years. The result? A dramatic rise in the number of overweight and obese Americans.

The National Institutes of Health (NIH) conducted several studies and found alarming changes in the number of calories people consume now compared with what they ate 20 years ago. For example, a portion of spaghetti with sauce and meatballs contained 500 calories 20 years ago. Today, a standard portion has about 1,025 calories.

Dinner entrees aren't the only foods that have been subjected to supersizing; beverage portions have increased in tandem. The 20-ounce soda Americans gulp down without a second thought today packs about 250 calories. According to the NIH, that's about 150 more calories than a portion of soda contained 20 years ago.

How To Determine Portion Size

So how can you conquer portion distortion? The American Cancer Society (ACS) offers the following tips to determine proper serving sizes:

  • The amount of meat recommended for a meal is 3 to 4 ounces—about the size of a deck of cards or a bar of soap.
  • A medium baked potato should be about the size of a computer mouse.
  • One cup of pasta is about the size of a tennis ball.
  • Bagels, which continue to grow every year, should be about the size of a hockey puck.
  • When shopping, pay close attention to the serving sizes noted on food labels. You may think the package contains one serving but it may be two or more.

Dining Out

When you're eating out, you can't always control the portions you're served, but these tips from the ACS can save you hundreds of calories per meal.

  • Eat a regular cheeseburger instead of a double cheeseburger to save 280 calories.
  • Order a medium soda instead of the large version to save 100 calories.
  • Try the grilled version of the chicken sandwich instead of the breaded version. You'll save 205 calories.
  • Enjoy the small fries instead of the super-size fries to save 330 calories.

Remember, although portion sizes may have increased, you don't have to eat everything you're served. If you're eating out, order an appetizer instead of an entrée, or ask that half of your entrée be wrapped before you begin eating.