Associação dos horários das refeições com o consumo alimentar e o ganho de peso durante a gestação: estudo de coorte prospectivo

Abstract

Introduction: Studies have suggested that not only what and how much you eat, but also when you eat (variables related to meal timing), contribute significantly to energy balance, calorie distribution throughout the day, body weight regulation and metabolic control. However, so far, few studies with pregnant women have been conducted in the field of chrononutrition (an area of science that studies the relationship between food consumption and the circadian clock). Objective: The aim of this study was to analyze the associations between meal timing and food intake and weight gain in pregnant women. Material and Methods: This is a prospective cohort study conducted with 100 pregnant women who were followed up at low-risk prenatal care at Unidades de Atendimento Integrado (UAIs) in the city of Uberlandia or at the prenatal service at the Hospital de Clinicas of Federal University of Uberlandia (HC-UFU). Data collection was performed between October 2015 and February 2017. Food intake was evaluated by three 24-h food recalls in each gestational trimester. The distribution of energy and macronutrients intake was evaluated at meals throughout the day. Diet quality was assessed using the Brazilian Healthy Eating Index-Revised (BHEI-R). Time-related eating patterns, i.e., the interval between the first and the last meal (eating duration), nightly fasting, time of the first and last meals and number of meals eaten in a day were determined. Pregnant women were classified as “early” or “late” based on the timing of the first and last meals, if the values were below or above the median of the population, respectively. Also, pregnant women were classified as “lower” or “higher” night-time energy intake - amount of energy intake from 19:00 to 05:59h - if these values were below or above the median of the population, respectively. The adequacy of the weight gain in the trimesters was evaluated based on the value of the weight gain in each trimester divided by the value of the recommended weight gain in this interval. Chronotype was derived using the mid-sleep time on free days on weekends (MSF), with a further correction for calculated sleep debt. Linear regression modeling analyses adjusted for confounders were used to investigate the association between time-related eating patterns and chronotype with diet quality in the first trimester. Generalized Estimating Equation models were used to determine the effects of the “early” or “late” meal timing and “lower” or “higher” night-time intake on the eating patterns, diet quality and weight gain during pregnancy. Results: The results showed that in the first gestational trimester a longer eating duration, earlier time of the first meal, higher number of meals and morningness tendency were associated with a better diet quality - higher scores of the total BHEI-R and/or fruit components. Data from the three gestational trimesters showed that the “early” eaters of the first meal consumed a higher percentage of energy and carbohydrates at morning meals and a lower percentage of energy and carbohydrates at evening meals, and had a better diet quality for the total fruit and whole fruit components compared to the “late” eaters of the first meal. In addition, the pregnant women with "higher” night-time intake had greater excessive weight gain in the third trimester when compared to "lower” nighttime intake. Conclusion: We suggest that having the first meal earlier is related to the better diet quality and the lower food intake in the evening meals, and that the lower energy consumption after 7 pm is related to the lower weight gain in the third trimester. Meal timing should be considered in the nutritional prenatal guidelines to promote adequate gestational weight gain and consequently maternal-fetal health.