To be climate-friendly, food-based dietary guidelines must include limits on total meat consumption – modeling from the case of France

Abstract Although food-based dietary guidelines (FBDG) include guidelines for meat consumption, their setting most often do not explicitly include environmental considerations. For instance, in France, FBDG recommend consuming no more than 500 g of red meat and 150 g of processed meat per week. This study uses modeling to investigate the range of greenhouse gas emissions (GHGe) that can be achieved under FBDG compliance. The study analyzed data collected in 2014 from 29,413 NutriNet-Santé participants to assess their adherence to the French FBDG. GHGe, cumulative energy demand (CED), and land occupation (LO) for organic and conventional foods were obtained from the DIALECTE database. Diets adequate in nutrients, culturally acceptable, and consistent with FBDG were modeled under different GHGe constraints. Environmental, nutritional, and health criteria were then calculated. The average observed adequacy to FBDG was low (19%, SD=25%) and GHGe were 4.34 (SD=2.7%) kgCO2eq/d. The GHGe range of the diets varied from 1.16 to 6.99 kgCO2eq/d, depending up to ∼85% on the level of meat consumption. Similar associations were observed for CED, LO and Health Risk Score. At isoenergetic diets, the diet with the lowest emissions had a higher proportion of vegetables, whole grains, and plant-based substitutes. This diet had a lower CED, LO, and a greater proportion of organic foods when compared to the diet with the highest emissions. While French dietary guidelines contribute, on average, to mitigating climate change and promoting health, this study emphasizes levers in recommended food consumption to more efficiently reduce diets’ GHGe and points to total meat as the critical issue to better account for pressure on climate change. Other environmental pressures should also be taken into account when designing dietary guidelines. Highlights The average greenhouse gas emissions of the observed diets was 4.34 (SD=2.70) kgCO2eq/d with an energy intake of 2080 Kcal/d The diet that closely resembled the observed diet under the dietary guidelines, nutrient and acceptability constraints (TD model) had emissions of 5.15 kgCO2eq/d . Modeled diets that complied with dietary guidelines and nutrient and acceptability constraints had emissions ranging from 1.16 kgCO2eq/d (model MinGHGe) to 6.99 kgCO2eq/d (model MaxGHGe). All modeled diets had higher consumption levels of fruit, vegetable oils, pulses, and wholegrain products. The MinGHGe and MaxGHGe diets, and the range of identified models in between, differed in their level of beef/lamb, refined cereals, fruit, pork, and snack products. The level of meat, especially beef/lamb, explained most of the difference (up to ≈85%) in GHGe across models. The level of total meat consumption varied progressively across models that imposed an increase in GHGe.