Ever wonder who decides how many Gummy Bears = 1 serving? (18) Or that one cup of Wheaties = 1 serving? Well, nationwide food consumption surveys do, but also the NHLBI (National Heart, Lung, and Blood Institute). So if you're wondering why a serving of ice cream is usually only a Â½-cup (on their Web site the NHLBI says no more than the size of half a baseball), it's because that's what they've determined is the right amount to stay healthy. Meanwhile, we all know how many baseballs Baskin Robbins scoops into their hot fudge sundaes--enough to fill a small bathtub, right?

The NHLBI has studied portion explosion over the last 20 years and has done a lot of groundbreaking research. The good folks over at DivineCaroline.com used that research, re-purposed some NHLBI photos from a fun portion explosion quiz, and tell us that "in the 1970s, around 47 percent of Americans were overweight or obese; now 66 percent of us are. In addition, the number of just obese people has doubled, from 15 percent of our population to 30 percent."

Scary stuff, right?

This all starts to make a lot of sense when you look at the following images, culled from the NHLBI site and DivineCaroline.com. Clearly the majority of us are eating more than 18 Gummy Bears.

#### 1. Two Slices of Pizza

You'd have to play golf (walking and carrying your clubs) for an hour to burn the extra 350 calories.

#### 2. Bagel

You would have to rake leaves for 50 minutes to burn the extra 210 calories added over the last 20 years to the average bagel.

#### 3. Movie Popcorn

You'd have to do water aerobics for 1 hour and 15 minutes to burn the extra 360 calories.

#### 4. Cheeseburger

You'd have to lift weights for1 hour and 30 minutes to burn off the 257 calories.

Yes, even "healthy" food has exploded in size over the last 20 years. You'd have to walk your dog for 1 hour and 20 minutes to burn the 400 calories. (If you don't have a dog, you'd have to buy one first.)

#### 6. Cup of Coffee

You'd have to walk 1 hour and 20 minutes to burn the extra 305 calories.

#### 7. Soda

In the early '70s, 6.5 ouncers were popular. Today it's 20 ounces, or more (Super Big Gulp = 44 oz = 700 calories!) You'd have to work in the garden for 35 minutes to burn the extra 165 calories.

#### 8. Turkey Sandwich

You'd need to ride a bike for 1 hour and 25 minutes to burn the extra 500 calories.

#### 9. French Fries

You'd need to walk leisurely for1 hour and 10 minutes to burn the extra 400 calories.

#### 10. Spaghetti and Meatballs

You'd need to houseclean for 2 hours and 35 minutes to burn off the extra 525 calories.