Scenario studies

The shortest route to a diet with lower environmental impact

Adopting a vegetarian or a vegan diet are options to decrease the environmental impact of the diet, but these restrictive diets require quite drastic changes of dietary habits. The graph below shows environmental impact of diets in relation to the change effort needed to reach a specific diet. All diets on the left side of the red line, the possibilities frontier, do not meet one or more dietary requirements, the others do. It is clear that a shift from the current diet to the closest healthy diet does not change the environmental impact. The change effort is a metric for the distance to the current diet. From this graph we learn that adopting a vegan diet gives a 30% drop in environmental impact, but is hard to reach, i.e., would require many changes in comparison with the current eating habits.
The same environmental impact level can be obtained with far less changes if there would be no constraints on specific products. All healthy diets depicted in the graph are optimized solutions calculated by Optimeal®.

Strategic position of products

Sustainable & healthy diets

The strategic position of products in sustainable and healthy diets depends on the balance between nutritive value and environmental impact. If this is favorable, an increase in the amount of product decreases the overall impact of the diet. Optimeal® can also give an indication of how difficult it is to replace a product. Based on this analysis, products and product groups can be placed into four quadrants.

A product that is hard to replace and with a positive contribution to the environmental impact of the diet has a strong position, while a product that is easy to eliminate and an increase would imply a worse environmental impact profile has a weak strategic position.

Comparative LCAs of foods

Comparing Apples & Oranges

An apple has a lower environmental impact than an orange, but the contribution of the orange to the total nutrient intake might be more valuable. Eating apples instead of oranges lowers the environmental impact of the diet, but ignores the difference in nutritional quality. With Optimeal® we determined that apples with some kiwi and strawberries are equivalent to oranges: they deliver more or less the same package of nutrients. The package of nutrients is our definition of the functional unit in the comparative LCS, whereas the amounts of products on both side of the equation are the reference flows delivering the functional unit. Without taking the kiwis and strawberries into account the difference in carbon footprint is 0.12 kg CO2 equivalents, which is reduced to only 0.03 kg CO2equivalents after the systems are made equivalent. So there is hardly any benefit for the environment left, when dietary quality is taken into account.