Earlier this year New York Mayor Michael Bloomberg proposed to legislate the sale of sodas and other sugar-sweetened drinks to 16 ounces or less. This controversial idea sparked much debate. It also shed light on the fact we are a nation suffering from “portion distortion.”

Today one in three Americans is overweight. Another third is obese, according to the Centers for Disease Control and Prevention. We can point to many reasons for this alarming trend, but one of the most obvious is an increase in what we define as the “average” portion size.

Take the following quiz to see if you can discern differences in today’s portion sizes of some common foods compared to 20 years ago. The answers at the end of the column also reveal just how much physical activity you will need to do to burn off all the extra calories we are consuming.

Why should we be concerned?

The latest studies on food consumption reveal startling facts that give insight to the worldwide epidemic of overfatness and type 2 diabetes. Americans consume more salt, sugar, and fat each year than any other nation in the world. On average we consume 86 pounds of fats and oils, 110 pounds of red meat (62 pounds of beef, 47 pounds of pork, 74 pounds of poultry, and 60 pounds of chicken), 33 pounds of eggs, 23 pounds of pizza, 24 pounds of ice cream, 24 pounds of artificial sweeteners, and 24 pounds of sodium. The figure below displays the amount of food consumed per pound for the average American in 2010. (See a full-sized version of the image below.)

Epidemiologic evidence associates higher rates of salt, sugar, and fat consumption with higher rates of heart disease, type 2 diabetes, and overfatness. In 2010, no state had a prevalence of obesity less than 20 percent, and 12 states, including Michigan, had an obesity prevalence of 30 percent or more.

The problem with portions

Part of the increased food consumption relates to the nearly 350 percent increase, since 1965, in the proportion of foods we consume from restaurants and fast-food outlets. For the first time in our history, the average American eats out more than at home.

Supersized servings of french fries and soda often are two-to-five times larger than when first introduced. In 1955 a single serving of McDonald’s french fries weighed 2.4 ounces and contained 210 kcals. At the time, only one size—regular—was available. In 2012 McDonald’s offers three sizes: small—2.5 oz. at 224 kcal; medium—4.1 oz. at 370 kcal; and large—5.4 oz. at 487 kcal!

A large popcorn in one of the country’s major movie chains contains 1160 kcal and 60 grams—or three days’ worth—of fat. A small popcorn contains 670 kcal—the same as a Pizza Hut Personal Pepperoni Pan Pizza.

Average portion sizes have expanded to such an extent over the past 20 years that the plate arrives with enough food for two, or even three, people. An “individual” bag of chips is enough for more than one person. And a bagel has become a BAGEL. These growing portion sizes are changing what Americans think of and expect as “normal.”

Supersizing: An American trend

The increasing size of American food portions links to the U.S. food industry’s growing reliance on value marketing, a technique to increase profits. Customers are encouraged to spend a little extra money on a larger portion, thus getting a “better” deal.

The negative nutritional and caloric costs of these so-called deals is enormous. Upgrading to larger serving sizes often increases price only modestly, but substantially increases calorie and fat content. This invariably contributes to overeating (and probably overfatness).

In addition to using price to encourage the purchase of larger portion sizes, fast-food sales personnel often suggest consumers upgrade or “supersize” to larger portions or “value meals” that deliver high-profit-margin, high-calorie soft drinks and side dishes such as french fries. This bundling of items profoundly influences the quantity of food customers eat.

Tips to avoid portion distortion

…When Eating Out

• Eat a portion of low-calorie raw vegetables before going out.
• Split an entrée with a friend.
• Ask for a “to-go” box and wrap up half of your meal when it arrives. Save it for your next meal.
• Order an appetizer in lieu of a full meal.

…When Eating at Home

• Replace the candy dish with a fruit bowl.
• Serve food on individual plates instead of using serving dishes.
• Keep excess food out of reach to discourage overeating.
• Eat a portion of low-calorie raw vegetables before dinner.
• Drink a glass of water before eating.

…When Eating or Snacking in Front of the TV

• First, try to avoid eating or snacking in front of the TV.
• If you do plan to watch TV during dinner, prepare low-calorie snacks like raw vegetables.
• Measure one serving size into a container instead of eating directly from the package.
• Be aware of large packages.
• Divide the contents of one large package into smaller containers.
• Store tempting foods out of sight. Move healthier food up front at eye level.
• Snack on whole grain cereals or plain popcorn (without butter) instead of chips and candy.

And now for the answers…

1. C: 350 calories for a six-inch bagel. Rake leaves for 50 minutes to burn the extra 210 calories.*
2. A: 590 calories for a cheeseburger. You need to lift weights for 90 minutes to burn the extra approximately 257 calories.*
3. B: 250 calories for a 20-ounce soda. Working in the garden for 35 minutes burns the extra 165 calories.**
4. B: 610 calories for a 6.9-ounce portion of french fries. Walk leisurely for 70 to minutes burn the extra 400 calories.**
5. C: 1025 calories for two cups of pasta with sauce and three large meatballs. If you clean house for two hours and 35 minutes you will burn approximately 525 calories.*
6. B: 350 calories for a 16-ounce cup of coffee. If you walk approximately one hour and 20 minutes, you will burn the extra 305 calories.*
7. C: 500 calories for a five-ounce muffin. Vacuum for 90 minutes to burn the extra 310 calories.*
8. A: 850 calories for two large slices of pizza. If you play golf (while walking and carrying your clubs) for one hour you will burn the extra 350 calories.**
9. C: 790 calories for a three-cup portion. You must walk the dog for one hour and 20 minutes to burn the extra 400 calories.**
10. B: 630 calories for a tub of popcorn. One hour and 15 minutes of water aerobics will burn the extra 360 calories.**