# Adherence to healthy and sustainable diets and health-related behaviors in a Spanish online university setting

## TL;DR

This study examines how well students and staff at a Spanish online university follow healthy and sustainable diets and how their health behaviors are connected.

## Contribution

The study introduces a new approach to evaluate adherence to healthy and sustainable diets using the HEASUS index in an online university setting.

## Key findings

- Adherence to healthy and sustainable diets was moderate, with students scoring 5.9 and staff 6.2 on the HEASUS index.
- Higher physical activity and active commuting were linked to better dietary adherence, while sedentary behavior and being overweight were associated with lower adherence.
- Health-related behaviors like sleep and emotional well-being were more strongly connected to diet quality among those with lower adherence.

## Abstract

Universities represent strategic environments for promoting healthy behaviors. Evaluating dietary quality and sustainability alongside other health-related factors is essential for developing health promotion strategies.

This study aimed to assess adherence to diets based on the latest Spanish healthy and sustainable dietary guidelines, and to explore associations between diet, health-related behaviors, and sociodemographic characteristics among students and staff at the Open University of Catalonia (UOC).

An online cross-sectional survey was conducted during the 2020–2021 academic year (n = 2,608; 2,075 students, 533 staff). Data on food intake (via a semi-quantitative food frequency questionnaire), physical activity (PA), sedentary behavior (SB), sleep quality, and emotional well-being were collected. HEAlthy and SUStainable diet index (HEASUS) was computed using a continuous gradient-based scoring system for 18 food groups, ranging from −1 (lowest adherence) to 10 (highest adherence). Quantile regression models were employed to examine determinants of HEASUS adherence across tertiles, accounting for health-related and sociodemographic covariates.

Overall, many participants exhibited low PA, insufficient sleep, and elevated stress. Adherence to healthy and sustainable diet according to HEASUS was moderate (students: 5.9 ± 1.5; staff: 6.2 ± 1.4). Higher PA and active commuting were positively associated with HEASUS, while SB, male gender, and overweight status were inversely associated. Health-related factors showed stronger associations with HEASUS adherence at lower quantiles, indicating that unhealthy behaviors cluster and reinforce each other more strongly among those with poorer dietary adherence. Although females scored slightly higher on HEASUS, they reported greater stress, poorer sleep, and higher SB.

Our findings underscore the importance of integrated, gender-sensitive strategies that jointly address diet quality, PA, sleep, and emotional well-being. Online universities represent an important setting for promoting both health and sustainability, especially through targeted actions that support a plant-rich, nutrient-dense dietary pattern, enhance emotional well-being, and encourage more active daily routines.

Infographic on healthy and sustainable diet adherence and health behaviors at a Spanish online university, showing students and staff average HEASUS scores between 5.8 and 6.4, bar graphs of self-reported habits, and icons for related behaviors.