Data from dietary intervention studies to test the ability of sustainable diets to meet micronutrient (MN) requirements is required. To compare MN intakes and status among adults who received dietary counselling to follow a sustainable diet or a standard healthy diet. We conducted a single-blind, randomized controlled trial among 355 healthy adults aged 18-64 years in three centers over 12-weeks. Participants received personalized dietary counselling; the intervention arm for a sustainable healthy diet and the control arm for a healthy diet. Greenhouse gas emissions (GHGE), MNs and biomarkers of nutritional status were assessed, and the prevalence of inadequate intakes was defined by the proportion of participants with usual intakes below harmonized Average Requirements. Data were analyzed using two-way mixed ANCOVA (time and treatment) on complete-cases. There were differential changes in intakes in the intervention arm compared to controls for GHGE (-22%), energy (-8%), retinol (-25%), thiamin (-11%), riboflavin (-16%), niacin (-16%), calcium (-16%), zinc (-13%), potassium (-10%), selenium (-15%), and iodine (-26%), vitamins B6 (-12%), B12 (-36%), C (-23%), D (-28%) and K1 (30%) (Pinteraction < 0.05). These were consistent following energy adjustment for retinol, riboflavin, niacin, calcium, iodine and vitamins B12 and K1. The prevalence of inadequate intakes of riboflavin, vitamins B6 and B12, calcium and zinc increased considerably, and at endpoint, there was a higher prevalence of inadequate intakes in the intervention arm for riboflavin, vitamins B6, B12 and C, calcium, zinc and selenium, than controls. Iron, iodine, vitamins A, D, E, C, and K1 status did not change. A diet based on sustainable dietary principles lowered dietary GHGE and several MNs, despite provision of daily servings of dairy, three weekly servings of animal protein and two servings of fish. These findings show that MNs should be considered in developing environmentally protective diets. Clinicaltrials.gov (NCT05253547).
Leonard et al. (Mon,) studied this question.