Environmental Footprint of a Low-Fat Vegan Diet in People With Type 1 Diabetes: A Secondary Analysis of a Randomized Clinical Trial

Abstract

A 12-wk randomized clinical trial found that adults with type 1 diabetes on a low-fat, vegan diet (n = 29) showed greater improvements in insulin sensitivity compared with a portion-controlled diet (n = 29). This secondary analysis calculates the greenhouse gas emissions (GHGEs) and cumulative energy demand (CED) of both diets by linking 3-d dietary records to external data sources. A repeated-measures analysis of variance was performed unadjusted and adjusted for change in energy intake. GHGE decreased in the vegan group by 55% (P = 0.001), compared with no change in the portion-controlled group (between-group P = 0.01). CED decreased in the vegan group by 44% (P = 0.01), with no change in the portion-controlled group (between-group P = 0.22). Energy intake was not a significant predictor of the observed changes. The decrease in GHGE and CED in the vegan group likely reflects reduced meat and dairy intake, suggesting that prioritizing plant-based foods over animal products may effectively reduce dietary environmental impact. This trial was registered at clinicaltrials.gov as NCT04944316 (https://clinicaltrials.gov/study/NCT04944316).

Keywords: cumulative energy demand; diet; environmental footprint; greenhouse gas emissions; nutrition; plant-based; vegan.