1. FAT FOOD TRAP: Bread
Bread-lovers in the study discovered that it was easy to eat too much of that food in a single sitting. If you can't live without sandwiches, then you should have them, but try to splurge on only those couple of slices of bread a day. Bread isn't evil; it just tends to be hard to control for people who love it.
WHAT TO EAT INSTEAD: Grains
Slice your protein or veggies over grains including whole-wheat pasta, wild rice, couscous, or quinoa.
Related: 10 Guilt-Free Summer Snacks 2. FAT FOOD TRAP: Fruit-flavored yogurt
When Weight Watchers asked 10,000 dieters to eat wholesome foods - like grains, vegetables, dairy, and lean protein - they saw that people often ate four containers of low-fat yogurt a day if the fruit was mixed in. But if the subjects had to stir in the fruit themselves, they stopped at only one cup.
WHAT TO EAT INSTEAD: Plain, nonfat yogurt - you add fresh fruit
Mixing in fruit yourself is enough to prevent you from mindless overeating, says Karen Miller-Kovach, R.D., chief scientific officer for Weight Watchers International and head of the healthy-eating program.
3. FAT FOOD TRAP: Breakfast cereal - even the healthy kind
The same Weight Watchers study also showed that people who ate cereal right out of the box as a snack tended to munch on way too much of it in a day. Even healthy, high-fiber cereals can up the day's calorie count and halt people's weight loss.
WHAT TO EAT INSTEAD: Eat cereal only with milk
This combination also decreases the meal's "calorie density" - an ounce of cereal with milk (skim, of course) has fewer calories than an ounce of cereal alone, so you'll take in fewer calories but still feel just as satisfied.
Related: 10 Surprising Foods That Pack On The Pounds
4. FAT FOOD TRAP: White rice
It takes more white rice than brown to make you feel just as satisfied. That's because white rice contains no fiber - a food component that helps you feel full. White pasta also tends to be fiber-free and less filling than whole wheat.
WHAT TO EAT INSTEAD: Brown rice
You might eat only 50 or 60 fewer calories when you make the switch to brown rice or pasta, but that can be enough to make a difference in weight loss, says Miller-Kovach.
Related: 5 Healthy Foods You Should Eat Every Day 5. FAT FOOD TRAP: 1 percent cottage cheese
At first, study participants tried incorporating low-fat, not just nonfat, products. "We don't know whether this higher-fat cottage cheese affected weight loss because of the little bit of fat it contains, or because people ate more of it," says Miller-Kovach.
WHAT TO EAT INSTEAD: Nonfat cottage cheese
Eating only the fat-free version allowed people in the study to continue losing extra weight.
6. FAT FOOD TRAP: Sugar-free hot chocolate
People who tried to satisfy their sweet cravings with sugar-free hot chocolate ended up drinking as many as five cups a day. "People would keep a mug on their desk and sip all day long, because they didn't think of the cocoa as a 'bad' food," says Miller-Kovach. But, of course, the calories add up.
WHAT TO EAT INSTEAD: Diet chocolate pudding
People who ate this instead of drinking cocoa stopped after a single serving, she says. "I think that people see pudding as a treat. They use it to satisfy the occasional sweet tooth, not to snack on all day."