A low-fat vegan diet has shown promise in helping people with type 1 diabetes cut their daily insulin needs by nearly 30%, according to new research. The study, published in BMC Nutrition, found that participants on this plant-based plan also saved on insulin costs without restricting calories or carbohydrates. In contrast, those following a portion-controlled diet saw no significant changes.
The research, a secondary analysis of a 2024 clinical trial conducted by the Physicians Committee for Responsible Medicine, involved comparing a low-fat vegan diet to a portion-controlled approach in individuals with type 1 diabetes. Over 12 weeks, participants on the vegan diet reduced their total daily insulin dose by 28%, equivalent to 12.1 units per day. This group also experienced a 27% drop in daily insulin expenses, amounting to $1.08 less per day, while the comparison group showed no notable reductions.
Type 1 diabetes requires insulin because the body does not produce enough of the hormone, which helps move glucose into cells for energy. Some patients develop insulin resistance, where cells do not respond well to insulin, often exacerbated by dietary fat. The study suggests the vegan diet improved insulin sensitivity, allowing better glucose management.
Beyond insulin use, the original 2024 trial reported further benefits for the vegan group, including an average weight loss of 11 pounds, better glycemic control, lower cholesterol levels, and improved kidney function. These outcomes occurred without calorie or carbohydrate restrictions.
The findings are particularly relevant amid rising insulin costs in the United States. National spending on insulin tripled over the past decade to $22.3 billion in 2022, with prices increasing 24% from 2017 to 2022 after inflation adjustments.
"As insulin prices continue to rise, people with type 1 diabetes should consider a low-fat vegan diet, which can help improve their insulin sensitivity and reduce the amount of insulin they need, potentially saving them hundreds of dollars a year," said Hana Kahleova, MD, PhD, lead author and director of clinical research at the Physicians Committee for Responsible Medicine.
The study was published in BMC Nutrition in 2025, with full details available via DOI: 10.1186/s40795-025-01175-2.
