Knowledge, attitudes and practices survey on fad diets in the Spanish population: "DiMilagro" cross-sectional study

Introduction: The recurrence of fad diets could be due to the difficulty of the population to modify their lifestyles and improve its adherence to therapeutic interventions. The objective of this work was to evaluate the level of knowledge, attitudes and practices on fad diets in a panel of consumers with socio-demographic characteristics assimilated to the Spanish population. Material and methods: Cross-sectional study through an on-line survey of knowledge, attitudes and practices, not validated and developed according to FAO guidelines, carried out on a sample of individuals between 18 and 65 years of both sexes. Results: 2,604 surveys were valid (50% women). The majority (57.9%) recognized some characteristics of fad diets and were able to identify them (65.8%). 90% of respondents believe that fad diets do not work and their effects are mainly negative (82.6%). 487 people (18.7%) reported having followed one or more fad diets, between 15 days and more than 6 months, used an associated product (56%) from herbalists (52%) and pharmacies (30%), and perceived some of the promised effects (57%), although 33% perceived some minor adverse effect. 73.7% of the total sample believe that fad diets are a problem and 78.6% believe that are dangerous. 82.1% do not feel vulnerability to follow a fad diet. Conclusions: The knowledge on fad diets is medium in the population studied, most perceive them as a problem but do not feel vulnerable or prone to follow a fad diet. However, 22% of the sample followed some kind of fad diets although only 18.7% recognize it. New research is needed to further explore how the population's level of knowledge and attitude towards fad diets is related to their practices.