(P14-094-23) Energy Intake Variation on Weekdays vs Weekends in Healthy, Non-Smoking Adults

Objectives: Evidence suggests energy intake is higher on weekends compared with weekdays; however, most studies are cross-sectional and use self-reported dietary intake. We used data from a study in which food was provided to examine energy intake changes across the week, hypothesizing that energy intake, appetite, and hunger would be higher on weekends than on weekdays.

Methods: We examined data from our previous randomized controlled trial on the effects of dietary variety on energy intake. Included in this analysis were 44 (10 M, 34 F) healthy, non-smoking adults (aged 37.1±9.1 y, BMI 26.2±4.1 kg/m²) randomly assigned to one of two variety groups (matched for BMI) and offered either a low variety (LV) or a high variety (HV) diet having either 4 or 10 entrée/side/snack/desserts daily for 13 d, and a constant variety of fruits and vegetables. Within each group, participants ate both low and high fat versions (20 and 42% energy), separated by a 1-month washout. Food was given in excess (1.25 x predicted energy requirement) and consumed ad libitum. Leftovers were weighed and total daily energy intake calculated. Participants also reported daily appetite and hunger ratings. Dietary restraint, disinhibition, and hunger at baseline were assessed by the Eating Inventory. For analysis, the 13-d data were collapsed to 7-d data by taking the mean values of 2 same days of the weeks. Within HV and LV groups, fat levels were averaged due to similar results across the week. Data were analyzed using repeated measures ANOVA and paired t-test.

Results: Characteristics at baseline did not differ significantly by group. Energy intake, hunger, and appetite did not change significantly across the 7-d week for either group. However, mean weekend energy intake was lower than on weekday energy intake for the LV group (-136±51 kcal/d; p=0.033), but there was no significant difference in mean weekday and weekend energy intake in the HV group (18±49 kcal/d; p=0.698). Hunger, satisfaction with amount of food and satisfaction with type of food provided did not differ significantly between weekdays and weekends for either group.

Conclusions: HV prevented the reduction in energy intake during the weekend that was observed in the LV group. Lowering the variety of diet may facilitate reducing energy intake on weekends and help manage body weight.

Funding Sources: NIDDK, USDA