Purpose Time-related eating patterns have been associated with metabolic and nutritional diseases such as obesity. However, there is a lack of representative studies on this subject. This study's aim was to assess the association between the timing of eating and obesity in a large and representative sample of the Brazilian adult population (POF 2008–2009 survey).

Methods Two days of adults’ food diary (n = 21,020) were used to estimate tertiles of first and last meal intake times, eating midpoint, caloric midpoint time, and calories consumed from 18:00 h onwards. BMI was estimated and its values, as well as excess weight (BMI ≥ 25 kg/m²) and obesity (BMI ≥ 30 kg/m²) were used as outcomes. Multiple linear and logistic regressions were performed.

Results The first (β = 0.65, 95% CI 0.37–0.93) and last food intake time (β = 0.40, 95% CI 0.14–0.66), eating midpoint (β = 0.61, 95% CI 0.34–0.88) and calories consumed after 21:00 h (β = 0.74, 95% CI 0.32–1.16) and 22:00 h (β = 0.75, 95% CI 0.18–1.32) were positively associated with BMI. The likelihood of having excess weight or obesity was significantly higher in the third tertile of the first food intake time (OR = 1.28, 95% CI 1.13–1.45 and OR = 1.34, 95% CI 1.13–1.58, respectively), last food intake time (OR = 1.16, 95% CI 1.03–1.32; and OR = 1.18, 95% CI 1.00–1.41, respectively), eating midpoint (OR = 1.28, 95% CI 1.13–1.45; and OR = 1.35, 95% CI 1.14–1.59, respectively) and energy consumption after 21:00 h (OR = 1.33, 95% CI 1.10–1.59).

Conclusion Chrononutrition meal patterns indicative of late meal intake were significantly associated with high BMI, excess weight and obesity in the Brazilian population.