BACKGROUND: The distribution of energy intake and types of food consumed throughout the day may influence health.
OBJECTIVE: This study investigated the association of energy intake and ultra-processed food (UPF) consumption in the morning, at midday, and in the evening with indicators of obesity.
DESIGN: A pooled cross-sectional analysis of the National Diet and Nutrition Survey (2008-2019) of adults residing in England, Wales, Scotland, and Northern Ireland was conducted. Food consumption was assessed using 4-day food diaries. UPFs intake was assessed based on the Nova food classification. The 3 time periods were classified as morning (5:00 am to 10:59 am), midday (11:00 am to 4:59 pm), and evening (5:00 pm to 4:59 am).
PARTICIPANTS/SETTING: This study included 5749 adults aged 19 to 64 years residing in private households in the United Kingdom.
MAIN OUTCOME MEASURES: The main outcome measures were overweight, obesity, and abdominal obesity. Body mass index (calculated as kg / m) values ≥25 and ≥30 were used to classify overweight (including obesity) and obesity, respectively. Abdominal obesity was defined as a waist circumference ≥102 cm for men and ≥88 cm for women. 2
STATISTICAL ANALYSES PERFORMED: Multivariable logistic regression assessed the associations between the percentage of energy intake and the percentage of energy intake from UPFs in the morning, at midday, and in the evening, and indicators of obesity. Models were adjusted for sociodemographic variables (ie, sex, age, ethnicity, region, year of the survey, and social class occupation), behavioral variables (ie, physical activity, smoking status, frequency of alcohol consumption, sleep duration, and weight-loss diet), and variables related to food consumption.
RESULTS: The highest percentage of energy intake in the morning (third tertile) was associated with a 19% reduction in the odds of being overweight (95% CI, 0.68 to 0.96), and the highest percentage in the evening was associated with a 21% higher odds of being overweight (95% CI, 1.01 to 1.44). A 10% increase in the percentage of energy intake from UPFs at midday and in the evening was associated with an 11% (95% CI, 1.02 to 1.20) and 10% (95% CI, 1.02 to 1.18) higher odds of overweight, respectively. The highest percentage of energy intake from UPFs in the morning, at midday, and in the evening (third tertile) was associated with a 26%, 25%, and 45% higher odds of obesity, respectively. A 10% increase in the percentage of energy intake from UPFs in the evening was associated with a 12% (95% CI, 1.03 to 1.22) higher odds of abdominal obesity.
CONCLUSIONS: The timing of energy intake was associated with overweight, and higher consumption of UPFs at all times of day was associated with obesity. The strength of the association between UPFs consumption and indicators of obesity was greater in the evening compared with the morning and midday.
