Nutrition bars have exploded onto the scene as meal replacements and 'healthy' snacks. But are they as healthy as they claim to be?
By Richard Trubo
WebMD Weight Loss Clinic - Feature
Reviewed By Kathleen Zelman, MPH, RD/LD
In today's on-the-run society, where sitting down for a meal is sometimes an impossible luxury, the emergence of nutrition bars may seem to be just what the doctor ordered. Though these pocket-sized bars once found favor primarily with serious athletes looking for a competitive edge, now anyone who feels the need for a nutritional boost may keep a few stashed in a purse or a briefcase.
In the current bar-wars environment, there are literally hundreds of these prewrapped and portable products competing for shelf space at gyms, health-food stores, and supermarkets, with names ranging from PowerBar and Luna Bar to Balance Bar and MET-Rx. But nutritionists agree that not all bars are created equal. There are high-carbohydrate bars, protein bars, energy bars, breakfast bars, brain-boosting bars, meal-replacement bars, diet bars, and women-only bars. And with so much to choose from, consumers hungering for a quick nutritional fix -- whether they're recreational athletes, workaholics tied to their desks, or overcommitted moms with barely a moment to spare -- may feel dizzy from all the product overkill and heavily hyped claims.
Digesting the Bar Facts
Without a doubt, grab-and-gobble nutrition bars are great for people who race nonstop from sunup to exhaustion. "They're a convenient alternative for someone who would otherwise be reaching for a doughnut or using the vending machines for snacks at the office," says Liz Applegate, PhD, lecturer in nutrition at the University of California at Davis. "But there's nothing magical about these bars. Most of them are fine, but some are too high in fat."
Dawn Jackson, RD, spokeswoman for the American Dietetic Association, concurs, noting that the bars are convenient, especially when you're physically active. "You wouldn't put a turkey sandwich in your pocket when you go on a bike ride, but you could easily bring one of these bars with you." However, she cautions, "some of the bars have as much sugar and as much saturated fat as a candy bar. So use them in moderation."
Steve Hertzler, PhD, RD, assistant professor of medical dietetics at Ohio State University, conducted a study showing that endurance athletes may not get the sustained energy boost that they're expecting from certain bars. In his research, he compared the effects on blood glucose levels of two popular energy bars -- the Ironman PR Bar and the PowerBar.
Hertzler found that the Ironman PR Bar provided increases in blood sugar levels that remained fairly steady, which could translate into enhanced performance for endurance athletes. By contrast, the PowerBar produced a quick rush of blood sugar, but it was followed by a rapid decline -- not much different than occurs with a Snickers bar.
The composition of the Ironman PR bar -- 40% carbohydrate, 30% fat, and 30% protein -- may have been responsible for its more sustained effect on blood glucose, says Hertzler. For endurance events, he "research shows that consuming a little bit of carbohydrate every so often during a race is going to improve performance."
Nutritionist Nancy Clark, MS, RD, points out that anything that provides calories will give you some energy. "Bananas give energy," says Clark, director of nutrition services at SportsMedicine Associates in Brookline, Mass. "Twinkies give energy. Energy bars give energy. That's because they all provide calories."
Food vs. Bars
Most nutritionists emphasize that even when consuming nutrition bars, don't let them crowd whole foods out of your diet. For a quick snack, you may be better off eating an apple or a banana. Before an athletic competition, says Hertzler, "a bagel or graham crackers can produce a response in blood glucose levels similar to some energy bars, and they cost a lot less."
Though nutrition bars are handy, Applegate says that you may be overrelying on them if there's a growing pile of wrappers in your car. "Some people go to Costco and buy boxes of energy bars, and feel, 'I'm doing a good thing by eating them,'" she says. "They may think that these bars are better than food. But there are ingredients in foods that are missing from these bars. Just as you wouldn't want to live only on peaches or only on tuna sandwiches, you need a lot more in your diet than just energy bars."
Instead of a nutrition bar, Jackson says you can choose an alternative snack like a container of low-fat yogurt with high-fiber cereal sprinkled in it, or a fiber-rich bagel with a tomato and a small slice of low-fat Swiss cheese melted on it.
When you're choosing and trying out nutrition bars, a number of factors may influence your selection. For example:
- Look for a bar that's low in fat (less than 5 grams of fat).
- When evaluating the fiber content of bars, aim for 3 to 5 grams of fiber, says Jackson.
- Particularly if you're watching your weight, check the calories listed on the label. For example, while a Luna Bar contains 170 to 180 calories, a MET-Rx 100-Gram Food Bar has 340 calories.
- "If you're shopping for a meal-replacement bar, choose one that has about 15 or more grams of protein, along with some fiber, and fortified with about 35% of the RDAs for vitamins and minerals," says Applegate, author of Eat Smart, Play Hard. Meal-replacement bars tend to be larger than other bars, with proportionately higher levels of carbohydrates, fats, and protein.
- Consume some real food along with the bar. "People can eat grape tomatoes with their bar, or a piece of fruit," says Jackson.
- If you consume multiple bars per day, make sure you're not biting off more vitamins and minerals than you should chew. For example, a fortified bar might provide 50% of the RDA for zinc, says Clark, author of Nancy Clark's Sports Nutrition Guidebook. If you're eating several bars a day, plus a multivitamin/multimineral pill and a bowl of fortified cereal like Total, you could be getting much more zinc than you need, she cautions, which might interfere with the absorption of other minerals, and even weaken your immune system.
To complicate matters, you may not be able to judge every bar by its wrapper. In October 2001, when ConsumerLab.com announced the findings of its independent laboratory tests of 30 nutrition bars, 18 did not meet the claims of ingredient levels on the label. More than any other misrepresentation, about one-half of the nutrition bars exceeded the carbohydrate levels stated on the wrapper (one bar promoted as a low-carbohydrate diet product claimed it had just 2 grams of carbohydrates, but testing showed it actually contained 22 grams).
Originally published Oct. 7, 2002.
Medically updated Jan. 20, 2004
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