A study reveals that adopting a low-fat vegan diet, characterized by high fiber and carbohydrate content and moderate protein intake, can lead to reduced insulin requirement, improved insulin sensitivity, and enhanced glycemic control in individuals with type 1 diabetes (T1D) compared to conventional portion-controlled diets.
The study compared the effects of a low-fat vegan diet, unrestricted in carbohydrates or portion size, with a conventional portion-controlled, carbohydrate-regulated diet in 58 adults with T1D, aged 18 years and above, under stable insulin treatment for the past 3 months.
Participants were randomly assigned to either the vegan diet group (n = 29), consisting of vegetables, grains, legumes, and fruits, or the portion-controlled diet group (n = 29), which aimed to reduce daily energy intake by 500-1000 kcal/day in overweight participants while maintaining a stable carbohydrate intake.
Primary clinical outcomes included total daily insulin requirement, insulin sensitivity, and glycemic control measured by A1c levels. Additional assessments covered blood lipid profile, blood urea nitrogen, blood urea nitrogen-to-creatinine ratio, and body weight.
The study concluded with 18 participants completing the vegan diet regimen and 17 adhering to the portion-controlled diet.
In the vegan group, total daily insulin dose decreased by 12.1 units/day (P = .007), and insulin sensitivity increased by 6.6 g of carbohydrate per unit of insulin on average (P = .002), with no significant changes observed in the portion-controlled group.
Participants on the vegan diet exhibited lower levels of total and low-density lipoprotein cholesterol, blood urea nitrogen, and a reduced blood urea nitrogen-to-creatinine ratio (P < .001), whereas both groups experienced lower A1c levels.
Body weight decreased by 5.2 kg (P < .001) in the vegan group, while no significant changes occurred in the portion-controlled group.
For every 1-kg weight loss, there was a 2.16-unit decrease in total daily insulin dose and a 0.9-unit increase in insulin sensitivity.
The findings suggest significant support for the therapeutic benefits of a low-fat vegan diet high in fiber and carbohydrates, low in fat, and moderate in protein in managing type 1 diabetes, according to the study’s authors.
Published in Clinical Diabetes, the study was led by Hana Kahleova, MD, PhD, from the Physicians Committee for Responsible Medicine in Washington, DC.
Limitations of the study included reliance on self-reported dietary intake data and a higher attrition rate due to meal and blood glucose monitoring. The study’s generalizability may be limited as it involved individuals seeking assistance for T1D management.