Pulses Twice a Week in Replacement of Meat Modestly Increases Diet Sustainability

The French food-based dietary guidelines recommend eating pulses at least twice a week and to reduce meat consumption. This study assessed the impact on the sustainability characteristics (nutrition, cost, environment) of individual diets of meeting the pulse guideline. Dietary data of 2028 adults from the Esteban survey were completed with the nutritional content (considering bioavailability on iron, zinc and protein), price and environmental impacts of foods. When the pulse guideline (i.e., 57 g/day) was not met, two substitution scenarios raised the quantity of pulses to the recommended level, in replacement of an equivalent portion of (i) starches or (ii) meat. Only 9.6% of the participants reached the pulse guideline. Diet sustainability characteristics improved with the meat scenario (nutritional indicators improved; diet cost, greenhouse gas emissions and acidification decreased), while several indicators deteriorated with the starches scenario. Zinc available for absorption slightly decreased in both scenarios while iron available for absorption decreased in the meat scenario only. Increasing pulse consumption to two portions/week could modestly improve the sustainability of diets when pulses replace meat but not starches. Cultural acceptability of that substitution still needs to be proven, and iron and zinc status of individuals at risk of deficiency should be monitored.