A low-fatvegan dietthat doesn’t limit calories or carbohydrates could help people withtype 1 diabetesreduceinsulinuse and insulin costs, according to new research by the Physicians Committee for Responsible Medicine published inBMC Nutrition. Insulin is a hormone that helps move glucose (sugar) from the blood into muscle and liver cells to be used as energy. People with type 1diabetesmust take insulin because their body doesn’t produce enough. Some people with type 1 diabetes may need to take additional insulin, because they have insulin resistance, a condition in which cells don’t respond well to insulin and glucose remains in the blood. Insulin resistance is strongly influenced by dietary fat, which can inhibit glucose from entering the cells. The new research, which is a secondary analysis of a 2024 Physicians Committee study, compared the effect of a low-fat vegan diet to a portion-controlled diet on insulin use and insulin costs in people with type 1 diabetes. The analysis found that the total dose of insulin decreased by 28%, or 12.1 units, per day in the vegan group, compared to no significant change in the portion-controlled group. The reductions in insulin use in the vegan group likely reflect improved insulin sensitivity, or how well the body responds to insulin. Total insulin costs decreased by 27%, or $1.08 per day, in the vegan group, compared to no significant change in the portion-controlled group. The 2024 study found that a vegan diet also led to an average weight loss of 11 pounds, improved insulin sensitivity and glycemic control, and improved cholesterol levels and kidney function in people with type 1 diabetes. The new research comes as insulin prices in the United States continue to rise. Spending on insulin in the United States tripled in the past 10 years, reaching $22.3 billion in 2022, due to the increased usage and higher price of insulin, according to the American Diabetes Association. The inflation-adjusted cost of insulin increased by 24% from 2017 to 2022. “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,” says Hana Kahleova, MD, PhD, the lead author of the study and director of clinical research at the Physicians Committee for Responsible Medicine. Kahleova, H., Maracine, C., Znayenko-Miller, T. et al. Can a vegan diet help people with type 1 diabetes save on insulin? A secondary analysis of a 12-Week randomized clinical trial. BMC Nutr 11, 188 (2025). https://doi.org/10.1186/s40795-025-01175-2