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Purpose This study aims at defining and quantifying strategies to reduce the environmental impact caused by public and private Danish meal service supplying vulnerable home-dwelling senior citizens. Besides informing the scientific community, the goal is to inform decision makers at municipal and private commercial kitchens about their potential role in significantly reducing the environmental impact of the meal services by conscious, deliberate, and sustainable choices at each step of the meal-selection-production-packaging-delivery-chain.

Methods The Danish meal service is represented by five public and private meal producers with a combined annual production of 1.2 million main meals targeted at sustaining senior citizens living at home throughout nine municipalities. Forty-seven main meal recipes, divided into five categories, represent the typically available meals: vegetarian, fish/seafood, pork, poultry, and veal/beef. The study quantifies the environmental impact of the five meal categories by consequential life cycle assessment, using three functional units (mass, energy, and protein content) to investigate if differential impacts among the meal categories can support sustainability-improving strategies. Two impact categories, global warming and the monetized overall environmental impact, were calculated for each recipe, including all ingredients and processing. The environmental impacts of packaging, meal delivery, and food waste were estimated separately.

Results and discussion The average environmental impact of main meals with veal/beef were 5-7 times higher than the average impact of all other meals, and 8-11 times higher impact than the impact of the average vegetarian meal. The ranges reflect differences in the chosen functional unit and impact category. Differences among the non-beef meal categories were smaller, with vegetarian and fish/seafood meals having the lowest impact. The average global warming impact of the average main meals was 3.70kg CO2-eq and the overall monetized impact 0.62 (sic). Impact of waste was 0.03-0.18kg CO2-eq and 0.007-0.023 (sic) per meal in kitchens, and 0.031-0.329kg CO2-eq and 0.006-0.041 (sic) for consumers. The environmental impact of packaging added 0.07kg CO2-eq and 0.006 (sic), and meal delivery 0.026-0.435kg CO2-eq and 0.005-0.09 (sic) per meal.

Conclusions The most important strategy for reducing the environmental impact of Danish meal service is to reduce the number of meals containing veal/beef. Vegetarian meals were rarely more sustainable than fish/seafood. Packaging, food waste, and delivery of meals played minor roles in the overall sustainability of Danish meal service, and the most efficient strategy to reduce the environmental impact of these activities would be to deliver meals weekly rather daily.