Grocery shelves are packed with bars that claim to promote the “low-carb” lifestyle. But many of these bars have are not what they seem. In 2001, consumerlab.com tested 30 nutrition bars and found that half of them contained more carbohydrates than they claimed. One product that supposedly contained only 2 grams of carbohydrates turned out to have 22. Most of the carbohydrates in these products come from sweetening ingredients like glycerin. Manufacturers claim these forms do not count as carbohydrates because they do not impact blood sugar levels.

However, the reality is they are still carbohydrates, and they can form up to 70 percent of a bar’s total calories.

The FDA requires all bar manufacturers to list total carbohydrate counts on their nutrition labels. However, many low-carb bars can be loaded with fat, which is even worse. Some bars contain 10 grams, or about 15 percent of your RDA, the same as a Milky Way bar. They may be high-fat candy bars in weight-loss packaging.

Energy bars are good fix for a no-time-for-lunch crunch

When you do not have time to breathe, let alone eat lunch, grabbing an energy bar is better than skipping a meal entirely, right? Yes, but they are appropriate in emergency situations only. They usually do not contain enough calories to keep you full, so you may end up overeating later. You are also missing healthier foods, like fresh fruits and vegetables.

They are a healthy grab-and-go snack

These bars claim to be great anytime snacks, full of vitamins and minerals. And many of them deliver. Luna bars, for instance, contain 100 percent of the daily requirements of 11 different nutrients, from vitamin C to riboflavin and niacin. Zone Perfect bars have at least 200 percent of the daily value of vitamin C, E and B6. However, nutrients are not all these bars contain. They are also chock-full of calories, an amount somewhere between a snack and a small meal. You may find that you are even hungrier after eating it because refined carbohydrates cause blood sugar levels to rise in your body. When they drop an hour later, you will be ravenous.

As if that isn’t bad enough, many of these products also contain 7 to 10 fat grams, usually in the form of unhealthy saturated fat or trans fatty acids, which clog your arteries and increase the risk of cancer and heart disease. While companies must list both total fat and saturated fat on the label, they are not required to include information on trans fats until 2006. Until then, check the label for the words “partially hydrogenated,” which indicate trans fats.