High nutritional quality is not associated with low greenhouse gas emissions in self-selected diets of French adults

Am J Clin Nutr. 2013 Mar;97(3):569-83. doi: 10.3945/ajcn.112.035105. Epub 2013 Jan 30.

Abstract

Background: Healthy diets are supposed to be more environmentally friendly because they rely mainly on plant-based foods, which have lower greenhouse gas emissions (GHGEs) per unit weight than do animal-based foods.

Objectives: The objectives were to estimate the GHGEs associated with the consumption of self-selected diets in France and to analyze their relation with the nutritional quality of diets.

Design: For each adult in the national dietary Individual and National Survey on Food Consumption (n = 1918), the GHGEs of his or her diet were estimated based on the GHGEs of 391 foods. Highest-nutritional-quality diets were defined as those having simultaneously 1) an energy density below the median, 2) a mean adequacy ratio (MAR) above the median, and 3) a mean excess ratio (MER, percentage of maximum recommended values for nutrients for which intake should be limited) below the median.

Results: MAR was positively correlated and MER was negatively correlated with diet-related GHGEs. High-nutritional-quality diets contained more plant-based foods, notably fruit and vegetables, and fewer sweets and salted snacks than did low-quality diets. After adjustment for age, sex, and energy intake, the consumption of sweets and salted snacks was negatively correlated with diet-related GHGEs, whereas the consumption of animal products and of fruit and vegetables was positively associated with them. After adjustment for energy intake, high-nutritional-quality diets had significantly higher GHGEs (+9% and +22% for men and women, respectively) than did low-nutritional-quality diets.

Conclusion: Despite containing large amounts of plant-based foods, self-selected diets of the highest nutritional quality are currently not those with the lowest diet-related GHGEs.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Animals
  • Choice Behavior*
  • Cross-Sectional Studies
  • Diet*
  • Energy Intake
  • European Continental Ancestry Group
  • Feeding Behavior*
  • Female
  • Food Preferences*
  • France
  • Fruit
  • Greenhouse Effect*
  • Humans
  • Linear Models
  • Male
  • Meat
  • Middle Aged
  • Models, Theoretical
  • Nutritive Value
  • Vegetables
  • Young Adult