(P13-029-25) Adults Using a Weight Loss App Exhibit Their Healthiest Eating Days on a Tuesday: Results of a Retrospective Analysis

Objectives: Noncommunicable diseases (NCDs) are the leading cause of death worldwide; with overweight, obesity and poor nutrition being key risk factors.

Seasonality is observed in dietary patterns throughout the year and it is known that nutritional quality (NQ) tends to be poorer over the weekend. However, less is known regarding days of the highest NQ.

This research explores dietary patterns of users of a mobile weight loss application to understand which days of the week exhibit the highest NQ.

Methods: Text food logs from 01.11.2023 to 31.10.2024 recorded by app users (18–70 years, 45–250 kg, 150–250 cm, initial BMI 25–60 kg/m²) were selected. Each log was scored Optimal, Good, Fair or Low by the app’s Nutrition Score (NS) which considers calorie density, protein, fiber, unsaturated and saturated fat, sugar, sodium and calcium. Nutrition claims (e.g. “Low in sugar”, “High calorie density”) were provided for each log. The shares of scores and nutrition claims on each day of the week were compared using the Kruskal-Wallis test.

Results: The sample size was 777,558 users (77.5% female), the median BMI was 32.1 (IQR 28.7–36.6) kg/m², the most frequent age group was 50–59 years (177,503, 22.8%), the total number of food logs was 34,467,622 with average of 92,406 (SD 27,868) daily tracks.

The lowest NQ was observed on the weekends, especially on Saturdays, with slight improvements on Fridays and Mondays, significantly — on other weekdays, with the highest NQ on Tuesdays with the highest share of Good (38.6% vs 35.2%) and Optimal (16.2% vs 13.5%) and lowest share of Fair (29.6% vs 32.6%) and Low (15.6% vs 18.8%) meal scores compared to Saturdays.

The most notable differences in shares of nutrient claims were in the proportion of meal tracks with “High in saturated fats” (26.8% vs 31.1%) and “Low in saturated fats” (45.2% vs 41.2%), “Low calorie density” (38.3% vs 33.4%) for Tuesdays and Saturdays, respectively. All differences were statistically significant (P-value < 0.01).

Conclusions: The nutritional quality of food logs from over 700,000 adults using a weight loss mobile application was highest on Tuesdays and poorest on weekends. The most significant differences seen in nutritional quality of food logs between these days were in “High in saturated fats”, “Low in saturated fats”, “Low calorie density” claims.

Funding Sources: This research received no external funding.