Background/objectives We aimed to validate the simplified nutrient profiling system (SENS) algorithm based on its ability to rank foods across the four SENS classes in relation to overall nutritional quality of both observed diets and nutritionally optimized diets. Subjects/methods Foods and beverages from the French nutritional composition database were classified according to SENS. Diets consumed by French adults in the latest national dietary survey (>19 years, n = 1719) were divided into four nutritional quality levels, and average daily frequencies (number of portions per day) of foods from the four SENS classes were compared between the four levels. Then, for each individual observed diet, one iso-caloric and nutritionally adequate diet was optimized, and variations in daily frequencies of foods from each SENS class between observed and optimized diets were estimated. Results In observed diets, as overall nutritional quality level of diet increased, daily frequency increased for Class-1 foods (3.5 to 8.7 portions/d) and decreased for Class-4 foods (6.8 to 3.0 portions/day). From observed to optimized diets, daily frequency increased for Class-1 foods for 98.4% of individuals and decreased for Class-4 foods for 94.2% of individuals. Class-2 and Class-3 foods also followed patterns that fit the expected ranking. Conclusions Results from two WHO-recommended validation approaches showed that the SENS algorithm adequately ranks foods according to their contribution to overall nutritional quality of diets, which is a pre-requisite to use for simplified nutritional labeling in Europe.