Padrões crononutricionais e suas associações com obesidade, síndrome metabólica e consumo alimentar entre adultos e idosos americanos: uma análise do National Health and Nutrition Examination Survey (NHANES) 2015 - 2018

Abstract

Introduction: Chrononutrition is a relatively new area that investigates the association between meal timing and composition aligned with the circadian rhythm and metabolism. Initial studies suggest that eating at later times is associated with worse food intake quality in terms of calories and macronutrients, in addition to metabolic outcomes that affect health. However, epidemiological studies are still scarce on the subject. Objective: Characterize the chrononutritional pattern of American adults and elderly people and investigate its association with obesity and metabolic disorders that make up the metabolic syndrome (article 1), and with caloric and nutrient intake (article 2). Material and methods: These are cross-sectional studies (Article 1: n=7379; Article 2: n=5777) with individuals over the age of 18, participants in the National Health and Nutrition Examination Survey (NHANES) 2015-2016 and 2017 -2018. Meal timing and food intake data were collected by two 24-hour recalls in both cycles. Fasting blood glucose, triglycerides and HDL cholesterol levels were measured using the enzymatic method. Obesity was defined by body mass index and metabolic syndrome as diagnosed by the National Cholesterol Education Program Adult Treatment Panel III criteria (NCEP-ATP III). In study 1, Poisson regression was performed to evaluate the association between independent chrononutritional variables (eating duration, tertiles of the first and last meal timing, eating midpoint and eating occasions) and obesity, abdominal obesity and metabolic parameters of the metabolic syndrome. In study 2, multiple linear regression was performed between the quartiles of chrononutritional variables and food intake. Results: The average eating window of participants, adults and elderly, was around 12 hours, which was then considered as the cutoff point for stratifying the two analysis groups (≤ 12 hours and > 12 hours). It was found that a longer eating window (> 12 hours) is associated with a higher prevalence of abdominal obesity in adults (IRR, 1.15; 95% CI, 1.03-1.28) when compared with those who ate their meals within a shorter eating window (≤ 12 hours). Adults in the third tertile of last meal timing (mean 22:03 h) had a higher prevalence of abdominal obesity compared to the first tertile (IRR, 1.12; 95% CI, 1.01-1.25). Furthermore, adults with a higher eating midpoint (second and third tertile) had a higher prevalence of elevated fasting blood glucose (IRR, 1.30; 95% CI, 1.07-1.59 and IRR, 1.65; 95% CI, 1.22-2.22, respectively). Among the elderly, participants with a longer eating window (> 12 hours) had a higher prevalence of high triglycerides (IRR, 2.74; 95% CI, 1.25-5.96) when compared to elderly people with a shorter eating window (≤ 12 hours). In article 2, the eating window was negatively associated with the first meal timing in adults (β= -0.83; p <0.001) and elderly people (β= -0.89; p <0.001), positively associated with the last meal timing in adults (β= 0.90; p <0.001) and elderly people (β= 0.98; p <0.001), and positively associated with eating frequency in adults (β= 0.54; p <0.001) and elderly (β= 0.50; p <0.001). A positive association between eating window and caloric midpoint was found only in the elderly (β= 0.19; p=0.021). No association was found between the eating window and/or caloric midpoint with total energy intake. Conclusion: A longer eating duration and late meal timing are associated with cardiometabolic risk and are not associated with greater caloric and nutrient intake in adults and elderly people in the American population. These results suggest that the benefits of a circadian rhythm-aligned eating duration in obesity and metabolic disorders go beyond a reduction in caloric intake.