Over the last decade, several studies have attempted to identify the influence of socioeconomic factors on individuals' food intake. The economic issue is of considerable significance, and it is sometimes suggested that this is probably the key variable of all in influencing food choice.
The objective of our study was to evaluate the importance of educational and economic factors in determining food choice in a representative sample of Portuguese adults. The study sample included all subjects (20621 women and 18271 men) older than 18 years who were asked about their dietary intake and socioeconomic status, when participating in the Portuguese third National Health Survey (ONSA, Ministry of Health, National Institute of Health - Dr. Ricardo Jorge) carried out in 1998-1999. Participants were selected from 21808 households distributed according to the five regions of Portugal (NUTS II), using a multi-stage random probability design. Trained interviewers inquired participants on several health related issues, including educational and economic characteristics, smoking status, physical activity, anthropometric data (weight and height), and food and beverages intake. Participants were distributed in four categories according to level of education (≤4 years, 5-9 years, and > 12 years) and income, that is, number of minimum salaries (≤2 salaries, 3-4 salaries, 5-6, and >6 salaries).
The consumption of soup, vegetables, fruit, bread and other starchy foods (pasta, rice and potatoes), fish, meat, milk and wine during the day before the interview was collected and recorded as a yes or no answer; consumption of spirits during the week before the interview was also registered as a yes or no answer. Separate logistic regression models were fitted for male and female to estimate the magnitude of the association between food groups and education/income, adjusting for age, body mass index, smoking habits, physical activity and income/education. In females, the odds favoring vegetables, fruit and fish consumption were respectively 1.67 (.37-2.03), 1.78 (1.37-2.30), and 1.38 (1.21-1.58) for those having >12 years of education compared to those with ≤4 years; the odds favoring wine, beer and spirits consumption were respectively 0.19 (0.14-0.25), 0.88 (0.65-1.17), and 0.16 (0.41-0.65) for those having >12 years of education compared to those with ≤4 years. In males, similar odds ratios were observed for vegetables, fruit, fish, wine and spirits, being the odds for beer statistically significant (OR = 0.55, CI 95% 0.46-0.65, p <0.001).
Overall, there were significant increases in the consumption of vegetables, fruit and fish and decreases in the consumption of wine and spirits, with increasing number of years of education. No such significant associations were observed for these food groups and income. One of the most interesting findings in terms of income and food consumption relation is that there is no evidence to suggest that if households increase their economic wealth, they transfer a significantly greater proportion of their income towards a different pattern of food choice.
In view of all the results presented so far, it is perhaps more interesting that education influences food choice in a more pronounced way than income.
P. Moreira, P. Padrao, University of Porto, Portugal