A process for controlling body weight of a consumer obtains food energy data of candidate food servings to be ingested based on a human beings metabolic efficiency in utilizing first and second nutrients of the candidate food servings and ingesting the food servings such that a sum of the food energy data thereof bears a predetermined relationship to predetermined food energy benchmark data of the consumer for a given period. Related processes for selecting and purchasing food, for producing food energy data and for producing a food product are provided. Related processes and systems for supplying food energy data to a requester and supplying meal plan data to a consumer are also provided. Food energy data are obtained with a processor and are associated with the food product e.g. by printing a label and putting this on the packaging of the food product.
