My patients frequently ask me if using nutrition bars would be of any benefit to their overall health or weight loss plan. I admit, even I grab one of these bars every now and then for a quick snack, or even lunch on a really busy day sometimes. In fact, I would much rather have my patients substitute a good nutrition bar for lunch than grab a high-saturated-fat burger and fries.These bars are convenient, they don’t require refrigeration, and, if you read labels before buying, they really can help you get some good nutrition in a hurry. Here’s what I tell my patients about the pros and cons of the “nutrition on the run” that these bars offer.Are All Nutrition Bars Alike?Seems every time I go to the health food store, there’s a new nutrition bar promising to be better tasting, or more vitamin/protein-packed than all the other bars! However, what tastes good to me may not to you, so, different flavors aside, let me explain what ingredients should be in a good nutrition bar.•Protein:For meal replacement, a good bar should have at least 15 grams of protein, preferably from whey or even casein protein and not soy, gelatin or collagen protein. Many bars, however, contain soy protein isolate, or a blend of whey, casein, and soy. Soy products can interfere with thyroid hormones as well as imbalance male and female hormones, as it adds plant estrogen, or phytoestrogens, to your body.•Fat: Should be fairly low in fat, not more than 3 grams saturated fat and 0 trans fat, 10 grams total fat. Steer clear of bars that contain cholesterol-boosting oils like palm kernel oil. Bars with polyunsaturated vegetable oils like olive, safflower, or coconut oil are best.•Carbohydrate: For meal replacement, there should be a balanced fat/carbohydrate/protein ratio, in a 40/30/30 distribution, i.e., 30% protein, 30% fat, 40% carbohydrate. If you want added protein only, then the carb and fat level can be lower than this distribution. Some bars can contain a whopping amount of sugar, however! Limit sugar to 10-15 grams.•Sugar Alcohols: Many low carb nutrition bars contain sugar alcohols. These help sweeten the bar without adding carbohydrates. When figuring the carbohydrate, or glycemic load, they should be subtracted from the overall carbohydrate content. For example, if the bar contains 25 grams of carbohydrate and also 20 grams of sugar alcohols, then the effective carbohydrate count would only be 5. Some people get digestive upsets from sugar alcohols which can be a drawback to bars that contain it.•Vitamins: A good bar has at least 1/3 of the minimum daily requirements for vitamins, usually in the 30% range for crucial vitamins like C, E, D, A. This is especially important if you are using a nutrition bar as a meal replacement.•Minerals: Many good bars also contain 1/3 the minimum daily requirement of necessary minerals like potassium, magnesium, calcium, zinc. Again, should be in the 30% range for meal replacement use.•Fiber: Many nutrition bars contain very little fiber, but several brands have between 4-6 grams. Or, at least have a piece of fruit, or a salad, with it to make up for fiber deficiencies.•Calories: If you’re using it as a meal replacement for a quick lunch, your nutrition bar should have between 200-300 calories in it. Otherwise you’ll be at the snack machine in an hour!Are There Any Cons to Nutrition Bars?We’ve talked about what I recommend a good bar should contain. Now, are there any real disadvantages, or cons, to using nutrition bars? As I tell my patients, I think that answer depends on how you use them. With that in mind, here are some possible disadvantages to using nutrition bars that you might consider when deciding to use them everyday or just occasionally:•Cost: Most good nutrition bars can cost anywhere from $2 to $3 a piece. This can get expensive if you use them everyday. However, if you use them as a meal replacement for one meal a day, that’s still less than the cheapest burger place for lunch, a lot less fat and salt, controlled calorie amount, and more vitamins and minerals.•Excessive Nutrition: If you’re using a nutrition bar for just a snack here and there, and not as meal replacement, look for one that has less than the 30% minimum daily requirement of vitamins and minerals to avoid over-intake of nutrients. This is especially true if you are taking a good vitamin/mineral supplement already everyday and eating well at your other meals. Too much Vitamin A can pose liver problems. Too much Vitamin E can result in excessive bleeding should you cut yourself.•May Contain Herbals: Steer clear of nutrition bars that contain “energy boosting” herbs such as ephedra, bitter orange, or even caffeine from green or black tea extracts which can affect some people’s heart rate or blood pressure adversely.•Taste: The taste of these bars can vary widely from brand to brand and price range. Some are in the “acquired” taste category and can be rather dry. Then there are others that really taste great. You really have to shop around and try a lot of different ones to find one you like and could eat on a regular basis.If you take medications, it’s always a good idea to ask your doctor about adding anything with vitamins/minerals in it that may interfere with absorption of your medications. Nutrition bars should not take the place of a balanced diet of whole foods, but they can provide a satisfying solution to a chocolaty-sweets craving, or provide a quick and nutritional meal on the run!