Can nutrition bars be part of a healthy diet and good diet plans? Most nutrition bars contain 200-250 calories-the same as a plain Hershey's  candy bar. But, some have as few as 100, and others contain more than 300. The bars typically have 4-7 grams of total fat.

Nutrition bars targeted at dieters are generally low in sugar and lower in total carbohydrates than those intended for athletes. Many diet bars contain sugar alcohols such as maltitol or lactitol, which are reduced-calorie  sweeteners that do not produce a spike in blood sugar and insulin levels.

Many experts advise you to avoid high energy (high calorie) bars. There's generally no need for high-protein bars unless you're a weight-lifter trying to build muscle.

One should also examine closely the ingredient list. Consider it a red flag if the first ingredient (which is the most abundant) is a form of sugar such as brown rice syrup, cane juice, malt extract or fructose.

Most nutrition experts say not to be lured by nutrition bars with herbs or amino acids, since there is little evidence that such ingredients are beneficial. If you also take a multi-vitamin and eat other fortified foods, you may wind up getting too much of nutrients such as vitamin A and iron. 

One can buy nutrition bars on their own in retail stores, or via medical or commercial weight loss programs they may be enrolled in (Weight Watchers, South Beach Diet, Jenny Craig, NutriSystem, LA Weight Loss, HMR, Medifast, and other diet plans). In drug stores and mass merchants, the bars are displayed in the weight loss products aisle, along with OTC diet pills, meal replacements, etc. They may also be sold at the counters of health club chains such as Curves for Women, Bally Total fitness, etc.