Losing weight would be a whole lot easier if we didn't have to monitor everything we put in our mouths. But the truth is, a calorie is a calorie, and having too many will pack on pounds, says Lisa Young, R.D., a dietician in New York City and author of The Portion Teller Plan (Broadway). "Nutritious foods like whole-wheat pasta and nuts can do just as much damage to a diet as pizza and cupcakes if you forget to watch how much you're eating," she says. To see serving-size slipups in action, we recruited two dozen volunteers and asked them to help themselves to five foods that are linked with a host of health benefits, including weight management. In nearly every case, our test subjects took more—sometimes two or three times more—than the recommended amount. Here's what we found, plus size-wise tips to make these nutritious foods do the weight-loss work for you.
Recommended serving: 3/4 cup (120 calories)
Testers' average serving: 1 1/2 cups (240 calories)
People who eat breakfast—particularly cereals—tend to have healthier body weights and also eat more fiber, which helps you feel fuller for longer. Plus, while dieting often leads to lower levels of important nutrients like iron and magnesium, fortified whole-grain cereals can help fill the gap.
—Buy a bowl that tells you your portion sizes. The Measure Up Bowl (shopmeasureup.com, from $14) looks like a regular dish but has discreet measurement lines at 1/2, 1, 1 1/2 and 2 cups.
—Pick a lower-calorie cereal if you like to see a full bowl. (Be sure to check the serving size when you're comparing calorie counts!) Boost the volume of your favorite hearty cereal by mixing it with a low-calorie type like whole-grain puffs (which generally contain 60 to 70 calories per cup).
Don't assume that your cereal bowl corresponds to the serving size on the box. If you're trying to lose weight, measure.