We revealed critical vulnerabilities of nutrient content claims under FDA per serving size (serving), CAC per 100 g or mL, CAC per serving, and CAC per 100 kcal and developed the proposed method to remove all vulnerabilities. We calculated the nutrient content of foods based on nutrient content claims under the proposed method. Then, we determined nutrient content claims for foods and food groups, and specified similarities between nutrient content claims in food groups. Also, we ranked foods and food groups based on met claims of the nutrient content. Nutrient content claims based on the proposed method, including free, very low, low, source, and high claims were determined in 8596 food items, 29 nutrients, and 25 food groups of the USDA National Nutrient Database for Standard Reference, release 28. Source and high claims are used for positive nutrients (including vitamins, minerals except sodium, protein, and dietary fiber). The very low claim is used for sodium, and free and low claims are used for cholesterol, energy, saturated fat, sodium, and total fat (also known as negative nutrients). In general, critical vulnerabilities of nutrient content claims under FDA and CAC can cause: (1) excessive energy intake based on FDA and CAC per serving and CAC per 100 g or mL; (2) exceeding the DV (NRV) for low nutrients under FDA per serving and CAC per 100 g or mL by consuming small amounts of foods per day; (3) the presence of nutrient free, but not low nutrient, foods based on FDA per serving and CAC per 100 g or mL; (4) the calculation of nutrient content in inappropriate amounts of foods based on FDA per serving, CAC per 100 g or mL, CAC per 100 kcal, and CAC per serving; and (5) determination of energy from total fat and saturated fat for relevant claims in inappropriate portions based on FDA per serving and CAC per 100 g or mL. Breakfast cereals, baby foods, pork products, lamb, veal, and game products, poultry products, and beef products had the highest average of scores for source and high nutrients. Restaurant foods, fast foods, and sausages and luncheon meats had the lowest average of scores for free, very low, and low nutrients. Nutrient source or high nutrient foods for all 24 positive nutrients were found in seven food groups (American Indian/Alaska Native foods; baby foods; beverages; dairy and egg products; legumes and legume products; meals, entrees, and side dishes; vegetables and vegetable products). There were very few source and high foods for potassium and vitamin D. Also, there were very few energy free foods.