15-Year Trends in the Patterns of Meal Timing and Eating Frequency Among US Adults

OBJECTIVES: To characterize trends in meal timing and frequency in US population age > 19 years. METHODS: We performed a serial cross-sectional analysis of 8 National Health and Nutrition Examination Survey (NHANES) cycles (2003–2018) on 34,470 adults (52.5% women and 21% black). Time of food and beverage intake was extracted from two 24-hour food recalls. The following meal timing measures were defined: 1) The time of the last and first calorie intake either from food or drink, 2) Eating window: The time elapsed between the first and last food intake, 3) Nighttime fasting duration: The time between last and first food intake, 4) Calorie midpoint time: The time when half of the calories for the day were consumed, 5) Late night eating: Consumption of ≥33% of total daily energy between 5:00 pm and midnight, and 6) Eating frequency: Frequency of food or beverage consumption >0 kcal which were >15 minutes apart. Population means for these variables were estimated for each cycle and survey-weighted linear regression was used to assess annual changes in meal timing and frequency over 15 years. RESULTS: From 2003 to 2018, survey-weighted mean (±SE) of eating window decreased from 12.21 ± 0.06 to 12.02 ± 0.05 hours/d in both men and women (Ptrend = 0.002). Time of the last calorie intake significantly decreased from 20.31 ± 0.04 to 20.09 ± 0.03 hours/d, while the time of first calorie intake and eating frequency remained unchanged. More than two-third of participants consumed ≥ 33% of total daily energy after 5:00 pm. Over the 15-year span, composition of diet also changed, including a decline in total calorie intake (from 2178.5 ± 18.4 to 2089.0 ± 21.2 kcal/d) and percentage of energy from carbohydrate intake (from 49.0 ± 0.4 to 46.4 ± 0.3%), while percentage of energy from dietary fats increased (from 34.0 ± 0.4 to 36.5 ± 0.2%), P(trend )< 0.05. CONCLUSIONS: Dietary intake of US adults has shifted to a lower % of calories from carbohydrates and a higher % from fat and a shorter eating time window. Caloric intake continues to be concentrated late in the day. These patterns are hypothesized to influence cardiometabolic health. FUNDING SOURCES: Samaneh Farsijani was supported by the K01 Career Development Award from the NIA (K01 AG071855-01A1) and the Pittsburgh Older Americans Independence Center (P30AG024827). Ziling Mao was supported by R01 AG059416 as a Graduate Student Researcher (GSR).