Protein bars are the easiest supplement category to get fooled by. The front of the box says "22g protein" in huge letters. The ingredient list, where the actual truth lives, is in 6-point font on the back. Here's how to read it like you're checking a process spec sheet, not a marketing flyer.
Net carbs are a math trick, not a law
"Net carbs" (total carbs minus fiber and sugar alcohols) is a formula the supplement industry uses, not the FDA. Our 22g protein pastry bar lists 8g net carbs, which assumes your body doesn't absorb the sugar alcohols and fiber at all. For most people that's roughly true. For some, sugar alcohols like maltitol still spike blood sugar and cause the well-known bathroom consequences of eating three bars in one sitting. If you're diabetic or very carb-sensitive, look at total carbs, not just the "net" number, and test your own response before trusting the label's math.
Protein quality, not just protein quantity
20g of protein from whey isolate and 20g of protein from collagen peptides are not equivalent. Whey and milk protein contain all nine essential amino acids in ratios your body uses well for muscle repair. Collagen is missing tryptophan and is low in a few others, so it's a poor primary protein source even though it counts fully toward the "protein" number on the label. Our peanut butter chocolate chip bar uses a vegan protein blend, worth checking the source (pea, rice, soy) if you're targeting muscle recovery specifically, since plant proteins vary more in amino acid completeness than whey.
Sugar count vs sweetener count
Our Endulge caramel nut chew bar lists 1g of sugar, which sounds great until you check what replaced it. Sugar alcohols and fiber both show up as "good source of fiber" on marketing copy, but eating multiple bars a day with high fiber or sugar-alcohol content is the single most common reason people blame protein bars for stomach issues. It's not the protein, it's the fiber and sugar alcohol load stacking up.
What to actually check, in order
Total carbs and fiber grams (not just "net carbs"), the specific protein source listed in the ingredients (not just the grams on the front), and sugar alcohol content if you're eating more than one bar a day. Three checks, thirty seconds, and you'll know more than what the box wants you to see first.
The bottom line
Protein bars are a snack, not a meal replacement, regardless of what the box implies. Use them to hit a protein gap between meals, check the actual ingredient panel before assuming "22g protein" and "keto" mean what you think they mean, and don't eat three in a row unless you've tested how your gut handles the fiber and sugar alcohol load.