Insulin is a hormone that moves glucose (sugar) from the bloodstream into muscle and liver cells, where it is used for energy. People with type 1 diabetes must take insulin because their bodies do not produce enough of it.

Some individuals with type 1 diabetes also develop insulin resistance, meaning their cells do not respond properly to insulin. When this happens, glucose stays in the bloodstream instead of entering cells. Dietary fat plays a major role in insulin resistance because it can interfere with the ability of glucose to move into cells efficiently.

Study Shows 28% Drop in Daily Insulin Dose

The new paper is a secondary analysis of a 2024 study conducted by the Physicians Committee. Researchers compared two approaches: a low-fat vegan diet and a portion-controlled diet. They examined how each plan affected insulin use and insulin costs in people with type 1 diabetes.

Participants following the vegan diet reduced their total daily insulin dose by 28%, or 12.1 units per day. In contrast, the portion-controlled group experienced no meaningful change. Researchers say the reduced insulin requirement likely reflects improved insulin sensitivity, which refers to how effectively the body responds to insulin.

Insulin expenses also declined in the vegan group. Total daily insulin costs dropped by 27%, or $1.08 per day, while costs remained essentially unchanged in the portion-controlled group.

Additional Health Benefits Including Weight Loss

The original 2024 study reported additional benefits from the vegan diet. Participants lost an average of 11 pounds and showed improvements in insulin sensitivity and glycemic control. Cholesterol levels and kidney function also improved among those following the plant-based plan.

Rising Insulin Prices in the United States

The findings come at a time when insulin prices in the United States remain high. According to the American Diabetes Association, national spending on insulin has tripled over the past decade, reaching $22.3 billion in 2022. Rising usage and higher prices have driven much of that increase. After adjusting for inflation, the cost of insulin rose 24% between 2017 and 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.

Founded in 1985, the Physicians Committee for Responsible Medicine is a nonprofit organization focused on preventive medicine, clinical research, and improving ethical and scientific standards in education and research.