Towards the in Silico Design of Diets: A Method for Reference Diet Templates Based on Objective Data and Institution Guidelines

Background: In silico diet design may represent a flexible approach in diet planning and adaptation to a variety of conditions, and it may take advantage of standard diet(s) as reference template(s). The concept of standard diet(s) is, however, quite vague and poorly defined. Objective: This work aimed to develop templates of omnivorous (OMN), lacto-ovo-vegetarian (LOV), and vegan (VEG) standard diets, based on data produced in European countries and the USA in 1998–2024, and adapted to an adult subject requiring about 2200 kcal/day. Design: Online databases were used to identify papers containing experimentally determined (EXP) data of daily food frequencies, or reporting dietary recommendations (REC) from (inter)national agencies or specific studies. Conclusions: The exclusion of meat, fish, and eggs in LOV diets is not compensated by increased dairy foods, but rather by more total vegetal foods and protein-rich vegetal alternatives. VEG diets replace animal-derived proteins mainly with nuts, seeds, and spreads, soy products, and protein-rich vegetal alternatives. Based on these data, templates to design “standard” OMN, LOV, and VEG diets are proposed.