Nutrition in life cycle assessments of foods

Life cycle assessment (LCA) is a standardised method for assessing the environmental impact of a product. For food, the result of an LCA is often expressed as ‘environmental impact per kg of product’. There is increasing interest in methods where the environmental impact is also assessed in relation to the nutritional quality or health properties o

So-called nutritional LCA (n -LCA) can be considered as an upgrade of the standard food LCA methodology, by including nutrition and health aspects as part of the LCA, either through the use of a nutrition-based functional unit (as an alternative to the traditional choice of functional unit, e.g. kilograms of product) or through the use of nutrition and/or nutritional quality or health aspects as an impact category, alongside other parameters affected by the production and consumption of the food, e.g. climate or biodiversity.

Two main approaches for including nutrition and health in food LCA.

Nutritional functional unit most common

The majority of n-LCA studies include nutrition aspects through the choice of functional unit. There are many approaches to choose from for functional unit selection. A nutrition-based functional unit can be based on the content/quality of single nutrients or be an index that includes multiple nutrients and/or other dietary aspects, e.g. whole grains or fruit and vegetables. The most appropriate method depends on the purpose of the study and the available data. The nutritional function of the food should be defined early in the LCA process and inform all subsequent methodological choices.

Method for more holistic assessment

n-LCA can be useful if the contribution of nutrients is a main function of the food. This is the case for most foods, with the exception of foods eaten primarily for flavour and pleasure (e.g. sweets and alcohol). n-LCA can also be used at the product level, but also for ingredients and complete diets.

n-LCA can be used, for example, to highlight and avoid conflicting objectives between different sustainability perspectives, and to enable a more holistic sustainability perspective in product development, marketing and communication of food.

Methodology by purpose

n-LCA should be planned and implemented by a multidisciplinary team of both environmental and nutritional scientists. There is no standardised methodology yet; instead, the methodology used should be identified based on the purpose of the analysis. The LCA practitioner and the nutrition expert should discuss the following aspects together:

What is the purpose and intended application?
What is the primary food to be assessed and what other foods is it relevant to compare the food in question with?
Who is the intended target population and are there specific nutritional needs to be considered?
What system boundaries should be used and will these affect the nutritional quality of the food under study
Should nutrition/health aspects be included in the analysis through the choice of functional unit or impact categories?