The current epidemic of obesity relates to the transition from traditional to industrialised diets. The present project investigates the effect on body energy of recommending the consumption of traditional "home meals", which may be a useful recommendation against obesity. A randomized controlled trial design is applied assigning participants to a recommendation of consuming during 12 weeks either "home meals" or "healthy meals." Frequency of consumption of energy-dense foods and of exercise is monitored throughout the intervention; weight and body fat are measured at baseline and at four-week intervals. The hypothesis is that consuming more frequently "home meals" reduces at least as much weight and adiposity as "healthy meals".

Obesity is a global health problem that requires effective intervention. In Mexico, 2 out of 3 adults are classed as overweight or obese. Weight gain from frequent consumption of energy dense food impairs the metabolism of lipids and glucose which causes the inflammatory state that underlies development of chronic illnesses such as cardiovascular disease. Mexican women with overweight or obesity consume on average 12 times per week food rich in sugar or fat. This indicates a high prevalence of unhealthy eating habits.

Such unhealthy habits are however determined by the modern environment. The raise in food availability is associated with increase in body weight at population level. Diverse studies indicate also an increase in the number of fast food outlets together with an increase in the frequency of eating out of the home. Therefore, people are exposed to abundance of unhealthy food that leads to acquire the habit of consuming them.

The informative education on "healthy" eating is a main intervention to abate obesity levels in the population. However, the prevalence of overweight and obesity is still increasing. In fact, if this trend continues, in 2025, 32 million of Mexican adults will achieve the diagnosis of obesity.

New perspectives for intervention are needed against obesity. We propose "home meals" as a novel strategy to enhance the effectivity of educative messages on "healthy" eating that generally presents food out of their cultural context. Our definition of "home meal" considers not only the physical space where foods are consumed but also a typical socially accepted preparation based on local foods. This proposal about "home meals" is partly made because the raise of obesity in the population coincides with the replacement of traditional diet by consumption of industrialised unhealthy food.

The present project develops an intervention that compares "home meals" vs. "healthy meals" with regards to their effect on weight and body fat. The aim is to test if the recommendation of eating "home meals" has a slimming effect and how it compares to that of the standard isocaloric recommendation of eating "healthy meals." The hypothesis is that because "home meals" are culturally tailored, they would be easier to practice, and so a similar weight/body fat loss to the "healthy meals" would be at least achieved.

Inclusion Criteria:

• BMI of 25 kg/m2 or above

Exclusion Criteria:

• Presence of chronic disease

Materials and dataset is available in the OSF platform

22 August 2019

Participants are only aware of the study condition in which they are allocated.