"When food companies take out one ingredient, they usually have to make up for the lost flavor by swapping in something else," says Karen Ansel, RD, co-author of The Calendar Diet: A Month by Month Guide to Losing Weight While Living Your Life.
In this case, the ingredient list more than doubles, the calorie count barely drops, and you get lots of extra sugar and sodium. Instead, Ansel recommends choosing all-natural peanut butter; the only ingredients should be peanuts and perhaps salt.
2. Gluten-free cookies
Gluten -- a mixture of proteins found in wheat, rye, and barley -- has gotten a bad rap lately, and many people mistakenly think "gluten-free" is code for healthy. Not necessarily.
"Unless you have celiac disease or gluten intolerance, gluten-free foods aren't necessarily better for you," says Lyssie Lakatos, RD, co-author of The Nutrition Twins' Veggie Cure.
3. Fat-free bottled salad dressing
"Many aren't much lower in calories compared to the full-fat versions," says Chicago nutrition consultant Janet Helm, RD.
She adds that people often eat too much of something when it's labeled fat-free. Helm suggests making your own vinaigrette with extra-virgin olive oil.
4. Turkey bacon
It sure sounds healthier, doesn't it? "It is slightly lower in fat and calories than regular bacon," Ansel says, "but it has upwards of 180 milligrams of bloating sodium per slice."
The problem is that turkey bacon falls in the category of "processed meats," which are high in sodium and other food additives that may have health risks. That's why health professionals recommend limiting processed meats like sausage, bacon, and hot dogs in your diet, even when they are marketed as leaner or more natural.
As with other foods, check the label to see what you're getting.