Scenario Analysis of a Municipality’s Food Purchase to Simultaneously Improve Nutritional Quality and Lower Carbon Emission for Child-Care Centers

Tracking progress toward a climate-friendly public food service strategy: assessing nutritional quality and carbon footprint changes in childcare centers

BACKGROUND

Public food procurement and catering are recognized as important leverage points in promoting sustainable and healthy dietary habits. This study aimed to analyze changes in nutritional quality and carbon footprint (CF) of food service in childcare centers in the City of Copenhagen from 2018 to 2022, following a new climate-friendly food strategy in 2019. The strategy has a target of decreasing the CF of municipal food service by 25% before 2025 compared to a 2018 baseline.

METHODS

Key initiatives in the municipality's strategy included creating guidelines for food-service providers to reduce their CF while ensuring meal nutritional quality and providing food professionals an advisory process to develop necessary competencies. In this quasi-experimental study, food procurement data from Copenhagen's childcare centers (n = 356 [2022]) from 2018 and 2022 were combined with CF and nutrient composition data. Dietary CF and food and nutrient content were calculated per 10 MJ of energy and compared to guideline targets. Furthermore, data for 2022 were analyzed separately for institutions that had received an advisory process (n = 87) and those that had not yet (n = 269).

RESULTS

On average, the CF of the food procurement decreased by 15%, mainly driven by a decrease in ruminant meat purchases (-37%). While the procurement of plant-based protein sources (pulses, nuts, seeds) increased by 25%, it was still considerably below targets. Nutrient content did not substantially change, and recommendations for calcium, iron, vitamin D, sodium, and total and saturated fat were not met in either measurement year. Institutions that had received an advisory process had a 14% lower CF in 2022 than institutions that had not.

CONCLUSIONS

With the observed 15% CF reduction, Copenhagen's childcare centers are on track to reach the 25% reduction goal outlined in the municipality's food strategy by 2025. Nutritional quality was largely unchanged, but further efforts to increase especially the consumption of plant-based protein sources, while simultaneously reducing meat and animal-based fat, and maintaining sufficient dairy consumption, are needed to improve nutritional quality and reach the target CF reduction in the coming years. Providing training for food professionals could play an important role in seeing the changes through.

Exploring healthy and climate-friendly diets for Danish adults: an optimization study using quadratic programming

Background

A transition to healthy and sustainable diets has the potential to improve human and planetary health but diets need to meet requirements for nutritional adequacy, health, environmental targets, and be acceptable to consumers.

Objective

The objective of this study was to derive a nutritionally adequate and healthy diet that has the least deviation possible from the average observed diet of Danish adults while aiming for a greenhouse gas emission (GHGE) reduction of 31%, corresponding to the GHGE level of the Danish plant-rich diet, which lays the foundation for the current healthy and sustainable food-based dietary guidelines (FBDGs) in Denmark.

Methods

With an objective function minimizing the departure from the average observed diet of Danish adults, four diet optimizations were run using quadratic programming, with different combinations of diet constraints: (1) nutrients only (Nutri), (2) nutrients and health-based targets for food amounts (NutriHealth), (3) GHGE only (GHGE), and finally, (4) combined nutrient, health and GHGE constraints (NutriHealthGHGE).

Results

The GHGE of the four optimized diets were 3.93 kg CO₂-eq (Nutri), 3.77 kg CO₂-eq (NutriHealth) and 3.01 kg CO₂-eq (GHGE and NutriHealthGHGE), compared to 4.37 kg CO₂-eq in the observed diet. The proportion of energy from animal-based foods was 21%-25% in the optimized diets compared to 34% in the observed diet and 18% in the Danish plant-rich diet. Moreover, compared to the average Danish diet, the NutriHealthGHGE diet contained more grains and starches (44 E% vs. 28 E%), nuts (+230%), fatty fish (+89%), eggs (+47%); less cheese (-73%), animal-based fats (-76%), total meat (-42%); and very limited amounts of ruminant meat, soft drinks, and alcoholic beverages (all-90%), while the amounts of legumes and seeds were unchanged. On average, the mathematically optimized NutriHealthGHGE diet showed a smaller deviation from the average Danish diet compared to the Danish plant-rich diet (38% vs. 169%, respectively).

Conclusion

The final optimized diet presented in this study represents an alternative way of composing a nutritionally adequate and healthy diet that has the same estimated GHGE as a diet consistent with the climate-friendly FBDGs in Denmark. As this optimized diet may be more acceptable for some consumers, it might help to facilitate the transition toward more healthy and sustainable diets in the Danish population.

Current Practices and Opportunities for More Sustainable Public Food Procurement: A Qualitative Study among Danish Municipalities and Regions

Public food procurement has been emphasized as a powerful tool to promote a healthier and more sustainable food system, but there is still a long way to go to reach full potential. This study aimed to investigate practices and opportunities for sustainable and healthy public food procurement. A qualitative cross-sectional study was performed among Danish municipalities and regions stratified and randomly selected to cover standard practice (n = 17). In addition, interviews were performed among selected best-practice municipalities (n = 5) providing examples of ambitious goals and well-defined processes for obtaining sustainable food procurement. Large differences were observed in the cross-sectional analysis in relation to policy support and goals for sustainable food procurement, including organic purchase. Generally, there was a great attentiveness to reduce food waste and many valued the use of local food, especially among rural municipalities, whereas experience with climate impact reduction and shifts towards more plant-based menus was still in an early implementation stage. Results suggest a possible synergy effect between the use of organic food and efforts to reduce food waste and climate impact and emphasize the importance of local government policies to promote healthy and sustainable food procurement. Enabling factors to move sustainable food procurement forward are discussed.

Carbon Footprint Reduction by Transitioning to a Diet Consistent with the Danish Climate-Friendly Dietary Guidelines: A Comparison of Different Carbon Footprint Databases

Dietary transitions are important for combating many of the environmental challenges humanity is facing today and reducing the global burden of disease. Different dietary patterns are associated with substantially different carbon footprints (CFs). This study aims to estimate the potential CF reduction on a transition from the current Danish diet to a plant-rich diet consistent with the Danish food-based dietary guidelines (FBDG) and to compare results obtained from the use of two different CF databases. Dietary intake data for adults aged 18–64 years from the national dietary survey 2011–2013 were used to calculate the CF of the current diet, and this was compared with the estimated CF of the plant-rich diet modelled for the FBDG. Calculations were carried out using an attributional life cycle assessment (LCA) database (AU-DTU data) and compared to calculations using a top-down hybrid consequential LCA database (BCD data). The transition from the current diet to the plant-rich diet showed a substantial estimated CF reduction of 31% with AU-DTU data, and a greater reduction with BCD data (43%). Ruminant meat reduction was the largest contributor to this CF reduction, especially with the use of BCD data, and other animal-based foods also contribute considerably to the CF reduction, especially with AU-DTU data. These results indicate that the choice of LCA methodology and CF database is important in estimation of dietary CF and for the development of guidelines to promote dietary change.

Guidance for Healthy and More Climate-Friendly Diets in Nursing Homes-Scenario Analysis Based on a Municipality's Food Procurement

Reducing the climate impact of food provided for residents in nursing homes is challenging, as the diets for older, frail adults must be high in protein content and energy density while at the same time ensuring that the meals are palatable and recognizable. This study aimed at providing guidance on healthy and more climate-friendly diets for nursing homes in the City of Copenhagen. The goal was to decrease greenhouse gas emissions (GHGE) by at least 25% while at the same time providing nutritionally adequate and recognizable menus. First, food purchase data were compiled with datasets matching each food item to a proxy food item and then to databases containing GHGE and nutrient information. Secondly, two diet scenarios were modelled based on current procurement practices, i.e., an energy- and protein-dense diet and a standard protein-dense diet, and converted into guidelines for menu planning. The diets contained less total meat, especially beef, and significantly more pulses, nuts and seeds in order to increase protein content according to recommendations for older adults. Finally, a combined scenario was calculated to reflect the joint climate impact reduction. This kind of innovation in food procurement is required in order to achieve the necessary transition to a sustainable food system.