Some people tend to use the labels "protein bar" and "energy bar" interchangeably, but they are two different type of bars. Generally, energy bars are aimed to provide a boost of energy through caffeine, sugar and carbohydrates while protein bars are packed with protein for a post-workout snack or meal replacement. There are often similarities in the ingredients of the bars, however, which can lead to confusion about their differences. Energy bars may also include protein and showcase the amount of grams of protein contained but you will notice it is generally much less than a protein bar.
When purchasing and eating either bar, it is important you pay attention to the amount of sugar in the bar. If you are using protein and energy bars as snacks or meal replacements with specific goals in mind, do your research as to which bars are healthiest for you or fit the macronutrients you require. Some of the best tasting protein bars that are similar to candy bars can contain as high as 30g of sugar and 20g of fat.
Another alternative to eating protein and energy bars are to have a protein shake or pre-workout shake. Again, it is best to read the nutrition label and ingredients list to ensure you are sticking to your goals. We often see people consuming these bars or drinks the more you train or if you are training consistently and rigorously, you've likely been recommended to have these supplemental foods as well. Although you can learn a lot about nutrition online, you should consult a health professional if you have any concerns.