Amount of Food Groups in a Healthy Diet with Low Environmental Impact: an Analysis Using Nitrogen Footprint

Abstract

Objective: We aimed to examine the characteristics of healthy meals with low environmental impact using nitrogen footprint (NF) to promote food choices that contribute to both global environment and health.

Methods: We calculated NF using the N-Calculator method using dietary data from 602 Smart Meals in the restaurants and ready-made meal section of the "Healthy Diet and Food Environment" certification system. We divided the meals into five groups (Q1, Q2, Q3, Q4, and Q5) with NF adjusted per 650 kcal. Then, we compared the amount and appearance rate of food groups using the chi-squared and Kruskal–Wallis tests among the five groups.

Results: A total of 509 meals were analyzed (analytic rate 84.6%). The NF per meal ranged from 9.46 to 48.89 g-N/650 kcal. The protein source food group had the highest percentage of NF among all five NF groups. The Q1 group, which had the lowest NF, used more potato/starch, sugar/sweeteners, seaweed, seafood, and oils and fats, and less vegetables, meat, and dairy than the other groups. The appearance rate of protein source food groups such as beef, pork, chicken, seafood, soybeans/processed foods, and eggs in the Q1 group was 0.0%, 12.9%, 4.0%, 89.1%, 48.5%, and 38.6%, respectively.

Conclusion: Even healthy diets made according to the same criteria differed in NF. Healthy diets with low NF mainly used protein source food groups other than meat.