Short- and Mid-Term Impacts of COVID-19 Outbreak on the Nutritional Quality and Environmental Impact of Diet

Behavioural determinants of healthy and environmentally friendly diets in French university students

Although encouraging the shift toward sustainable diets in young adults is a major challenge to preserve population and planet health, the precursors of sustainable diets in this population remain unknown. This study aimed to identify the behavioural determinants of healthier and more environmentally friendly diets among university students. A sample of 582 French university students reported their food consumption using an online 125-item food frequency questionnaire. The nutritional quality (adherence to French recommendations, sPNNS-GS2) and the greenhouse gas emissions (GHGE) of students' diets were calculated for an isocaloric diet. Behavioural determinants were measured based on a literature review and classified into the Capability, Opportunity, Motivation Behaviour (COM-B) framework. Linear models, adjusted for socioeconomic characteristics, were run to identify the most prominent behavioural predictors of nutritional quality and GHGE of students' diets. Higher cooking skills (β = 0.38, p = 0.01) and health motives (β = 0.91, p < 0.001) were associated with higher nutritional quality. Greater environmental knowledge was linked to lower GHGE (β = -0.07, p = 0.002), while health and weight control motives were associated with higher GHGE (β = 0.26, p = 0.02 and β = 0.39, p < 0.001). Enhancing cooking skills and environmental knowledge could enable healthy and environmentally friendly diets, but health-based motives can act as a lever and as a barrier.

Identification of three dietary groups in French university students and their associations with nutritional quality and environmental impact

Introduction

The student period is associated with changes in eating habits, usually leading to diets of lower nutritional quality. However, some variability may exist in students' dietary patterns. We aimed to describe French students' diets and identify dietary groups that may vary in nutritional quality and environmental impact.

Methods

A representative sample of French students (N = 582) for age, sex and scholarship status completed an online 125-item food frequency questionnaire. The nutritional quality of diets was assessed by a score of adherence to the French nutritional guidelines (sPNNS-GS2 score, ranging from-17 to 11.5) and its environmental impact by greenhouse gas emissions for an isocaloric diet (GHGE). An ascending hierarchical classification analysis on food and beverage intakes led to three dietary groups. Between-group differences in food consumption, dietary indicators and sociodemographic characteristics were investigated using ANOVA models.

Results

The average sPNNS-GS2 score of students' diets was -0.8 ± 2.8, representing a 57% coverage of French nutritional recommendations, and GHGE were 5.4 ± 1.7 kg eCO2/2000 kcal. The three dietary groups were: a healthy diet group (20% of the sample) with the highest nutritional quality and high GHGE, which included older students with a higher level of physical activity; a Western diet group (40%) with the worst nutritional quality and high GHGE, which included more students who lived with their parents; and a frugal diet group (40%) with the lowest energy intake, intermediate nutritional quality, and low GHGE, which included more students who lived alone.

Conclusion

None of the dietary groups optimized both nutritional quality and environmental impact simultaneously, which suggests an apparent incompatibility in the student population between these two sustainability dimensions. These findings emphasize the need for tailored public health policies that acknowledge the diversity of student eating patterns and address specific individual barriers to healthy and sustainable diets.

Associations of food motives with red meat and legume consumption in the population-based DILGOM study

PURPOSE

To improve human health and environmental sustainability, red meat consumption should decrease and legume consumption increase in diets. More information on food motives, however, is required when developing more tailored and effective interventions targeting legume and meat consumption. We aimed to examine the associations between food motives and red meat and legume consumption, and whether these associations differ between different subgroups (gender, age groups, marital status, education, BMI).

METHODS

Ten food motives (health, mood, convenience, sensory appeal, natural content, price-cheap, price-value, weight control, familiarity and ethical concern measured with Food Choice Questionnaire) were studied in 3079 Finnish adults in the population-based DILGOM study. Food consumption was assessed with Food Frequency Questionnaire. The adjusted estimates from multivariable regression models are reported.

RESULTS

Higher relative importance of natural content (β = - 0.275, 95% CI - 0.388; - 0.162) and ethical concern (β = - 0.462, 95% CI - 0.620; - 0.305) were associated with lower red meat consumption, and higher appreciation of sensory appeal (β = 0.482, 95% CI 0.347; 0.616) and price-cheap (β = 0.190, 95% CI 0.099; 0.281) with higher red meat consumption. Higher importance of health (β = 0.608, 95% CI 0.390; 0.825) was associated with higher legume consumption, and higher appreciation of convenience (β = - 0.401, 95% CI - 0.522; - 0.279), price-value (β = - 0.257, 95% CI - 0.380; - 0.133) and familiarity (β = - 0.278, 95% CI - 0.393; - 0.164) with lower legume consumption. The associations of particularly ethical concern, weight control, sensory appeal and mood varied according to gender, age, marital status or BMI.

CONCLUSION

The development and implementation of actions to decrease red meat and increase legume consumption should focus on several food motives across different subgroups.

Aligning Environmental Sustainability, Health Outcomes, and Affordability in Diet Quality: A Systematic Review

Improving diet quality while simultaneously maintaining planetary health is of critical interest globally. Despite the shared motivation, advancement remains slow, and the research community continues to operate in silos, focusing on certain pairings (diet-climate), or with a discipline-specific lens of a sustainable diet, rather than examining their totality. This review aimed to summarize the literature on adherence to a priori defined dietary patterns in consideration of diet quality, metabolic risk factors for noncommunicable diseases (NCDs), environmental impacts, and affordability. A methodology using PRISMA guidelines was followed, and searches were performed in 7 databases as of October 2022. The Appraisal tool for Cross-Sectional Studies (AXIS) and the National Institutes of Health (NIH) quality assessment tool for observational cohort studies were employed for quality appraisal. The evidence was narratively synthesized according to the characteristics of the diet quality metrics. The review includes 24 studies published between 2017-2023. Thirteen distinct diet quality scores were identified, with those measuring adherence to national dietary guidelines the most reported. Thirteen distinct environmental impact indicators were identified, with greenhouse gas emissions (n=23) reported most. All studies reported on body mass index, and 7 studies assessed the cost of adherence. Our results are consistent with previous findings that healthier diets can reduce environmental impacts; however, incongruities between population and planetary health can occur. Hence, the "sustainability" of dietary patterns is dependent on the choice of indicators selected. Further, healthy, lower impact diets can increase financial cost, but may also provide a protective role against the risk of obesity. Given the Global Syndemic, strategies to reduce obesity prevalence should emphasize the win-win opportunities for population and planetary health through dietary change. Research should identify diets that address multiple environmental concerns to curtail burdens potentially transferring, and harmonize this with sociocultural and equity dimensions. This review was registered at PROSPERO as CRD42021238055.