Seasonal variation in food intake and the interaction effects of sex and age among adults in southern Brazil.

BACKGROUND/OBJECTIVES
Because studies have evidenced variations in nutrient intake, further investigation of the interaction between demographic characteristics and the seasons is necessary. We aimed to test the differences in food intake throughout the seasons and the interaction between the seasons and sex and age.

SUBJECTS/METHODS
This study included 273 individuals. Food intake was evaluated with 24-hour dietary recalls, and the reported food items were sorted into food groups. We performed the test on the differences in intake of food groups throughout the seasons with repeated measures and on the interaction effect by using the Generalized Estimate Equation.

RESULTS
Intake of fruits and natural fruit juices and sweetened beverages was lower, whereas that of grains and derivatives was higher in the winter. The intake of leafy vegetables and fish and seafood was lower in the autumn. The consumption of coffee and eggs was higher in the spring. Intake of chocolate powder and sugar, salt and lean poultry was higher in the winter. The variation in consumption of grains and derivatives, eggs, fatty poultry and processed meat over the seasons was more likely to be modified by sex. Age interacted with the seasons for leafy vegetables, beans and lentils, lean beef, lean poultry, low fat milk and light yogurt, vegetable oil and unsalted margarine, chocolate powder and sugar and processed meat.

CONCLUSIONS
This study shows that food intake may change seasonally and that seasonal variation depends on sex and age, which might aggregate a specific co-variation component.