Chrononutrition Patterns in People Who Attempted Weight Loss in the Past Year: A Descriptive Analysis of the National Health and Nutrition Examination Survey (NHANES) 2017–2020 Pre-Pandemic

Introduction: Obesity is associated with cardiometabolic diseases, and chrononutrition has become a novel weight loss strategy. However, few have characterized chrononutrition patterns among people attempting weight loss. This study characterizes chrononutrition patterns in a nationally representative sample of U.S. adults who attempted weight loss in the past year through dietary modifications by weight change and adiposity. Methods: This cross-sectional analysis utilizes NHANES 2017–2020 data. Chrononutrition patterns were assessed using 24 h dietary recalls. Participants self-reported weight loss attempts in the past year and if they tried using diet modification. Weight change (loss, maintenance, and gain) was defined based on differences in current weight and weight one year prior. We used latent profile analysis and descriptive statistics. Results: The sample included 2107 participants who attempted weight loss in the past year through diet modification (median age 47; 58% women and 62% white). Individuals who gained weight (vs. loss) had longer hours between waketime and the first eating (1.78 vs. 1.62 h, p = 0.024), consumed a lower proportion of calories later in the day (43% vs. 52%, p < 0.001), and ate less frequently (5.20 vs. 5.43 episodes, p = 0.008). Participants with obesity had the shortest eating window (11.77 vs. 12.22 h, p = 0.02) despite a longer delay between waketime and the first eating (1.80 vs. 1.29 h, p < 0.001) and lower eating frequency (5.16 vs. 5.97, p < 0.001). Conclusions: Variations in eating timing, eating episodes, and caloric distribution suggest that chrononutrition may play a role in personalized weight management strategies.