Factors that influence food consumption¹

The factors that influence food selection are not restricted to personal preferences; they are also conditioned by social, cultural, and economical circumstances², food costs, accessibility, and the knowledge of how to design a healthy diet³. According to some authors, groups who have low purchasing power have a greater tendency to consume an unhealthy diet and fewer fruit and vegetables (FV)⁴ and others suggest that healthy diets are more expensive than those high in sugars, fat, and refined cereals.

Eating habits that are acquired during childhood may persist into adulthood⁶; therefore, factors that influence food consumption should be identified in order to carry out more effective interventions that will promote a healthy diet during the entire lifespan⁷.

According to the National Institute of Public Health⁸, the Mexican adult female population consumes two servings of FV per day, which is below recommendations for chronic disease prevention. According to published international studies9, nutrition education programs for children must include a number of key elements to have a successful outcome. These programs must be based on behavioural and environmental modifications, involve the family when the children are young, engage the school to modify the environment, embrace the community, and include sufficient time to instruct program participants. In order to achieve a successful outcome, it is necessary to know how these factors interact with the target population.

The frequency of fruit and vegetables consumption by urban Mexican school children, and their personal and environmental correlates were studied with 327 children (49.2% males and 50.8% females) attending second, third and fourth grades, with a mean age of 8.8 years, from two socioeconomically deprived state schools in Mexico City.

A validated written self-completed questionnaire was designed and administered to study subjects to identify the environmental (accessibility) and personal characteristics (preferences, expectancy, knowledge, and self-efficacy) that influence FV consumption.

The median intake of FV in our study was one time per day, with only 11% of the children eating ≥ 3 times per day. When analysed by gender, a significant difference existed in the FV consumption between girls and boys (p< 0.01), with a higher proportion of girls consuming 3 or more times per day (15.2% vs. 6.7%). This intake is very low when compared with the recommendations made by the World Cancer Research Fund (1997) (≥ 5 servings/day).

In relation to the BMI for age, 63.6% of the boys and 51.5% of girls in the study were overweight or obese, (χ2 = 4.826; p< 0.03). There was a significant difference in time spent watching television or playing video games between boys and girls (χ2 = 7.53; p<0.006); 48.5% of boys and 33.5% of girls spent ≥ 4 hrs per day in these sedentary activities.

There was a significant association was found between self-efficacy for vegetables and higher frequency of FV intake. However, no association was observed betweenfrequency (≥ 3 times /day) of FV intake and knowledge, preferences for fruits or for vegetables, expectancy, or selfefficacy for fruit.

Two factors that most influenced a higher (three or more times/day) intake of fruits and vegetables in this population were high accessibility (OR 3.38, CI 1.26 to 9.0) to FV and being a female (OR 2.2, CI 1.04 to 4.7). Several studies10, have previously found high accessibility as the variable most associated with FV consumption. Blanchette et al.11(2005) found that availability, accessibility, and parents’ example are the variables that most influence FV intake, and, therefore, intervention strategies to increase consumption should be based on these factors.

In focus groups with parents of similar children in the same schools (Pérez-Lizaur, unpublished data), the parents said that sometimes they find it difficult to prepare FV in a manner that are readily accessible to their children. The parents also believed that their children do not have the capacity and, in some instances, the interest to take part in the food preparation process, limiting their opportunities to be exposed to healthy eating habits. It would be interesting to explore how these beliefs affect children’s accessibility to FV, and in what way these barriers could be overcome to benefit both parents and children. Home and school environments that encourage consumption of fruit and vegetables are fundamental for the children to increase their FV consumption. It is also important to find creative ways to involve boys in food preparation activities, to encourage them taste more FV to promote consumption.