The diet experts suggest could help people with diabetes

Switching to a low-fat vegan diet can cut daily insulin use by nearly 30 per cent for people with type 1 diabetes, a new study has found.

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

Researchers compared the effect of a low-fat vegan diet and a portion-controlled diet on type 1 diabetics. They found the vegan diet reduced their total needed daily insulin dose by 28 per cent or 12.1 units per day, whereas the control group experienced no meaningful change.

A reduced insulin requirement likely means the body has improved insulin sensitivity, which refers to how effectively the body responds to insulin, according to the Physicians Committee for Responsible Medicine, which published the study in the journal BMC Nutrition.

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Dr Hana Kahleova, the lead author of the study, said: "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.”

The new analysis was a follow-up to a 2024 study also conducted by the Physicians Committee, which found additional benefits to having a vegan diet.

Participants lost an average of 5kg and showed improvements in insulin sensitivity and glycemic control. Cholesterol levels and kidney function also improved among those following the plant-based plan.

Previous studies have also shown that plant-based diets had a 32 per cent lower incidence of type 2 diabetes and 18 per cent lower greenhouse gas emissions linked to their diets.

Professor Louise Goff, from the Leicester Diabetes Centre, told The Independent: “The reduction in insulin dose seen in the vegan group is certainly noteworthy — but it’s crucial to understand why that likely occurred.

“Over the 12 weeks, participants following the vegan diet lost weight. Even in people with type 1 diabetes, weight loss improves insulin sensitivity. When the body becomes more insulin sensitive, less exogenous insulin is required to achieve the same glucose control.

“So, the reduced insulin dose is very likely a reflection of improved insulin sensitivity secondary to weight loss, rather than a direct effect of eliminating animal products per se.”

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Ms Goff also noted a significant increase in fibre intake in the vegan group, which is strongly associated with weight loss and improved insulin sensitivity — both of which would naturally reduce insulin requirements.

“This doesn’t diminish the potential benefits of plant-based eating, but it suggests that the mechanism is metabolic (weight loss and improved insulin sensitivity), not specific to veganism itself,” she added.

“It would be interesting to see whether similar results occur with other high-fibre, calorie-controlled dietary patterns.”

Professor Stefanie Baldeweg, former clinical lead of the department of diabetes at University College London, said: “Nutrition can be a powerful adjunct in diabetes management. But it is one tool among many – and should be approached thoughtfully.

“The findings are promising but preliminary. Patients should not alter insulin regimens without medical supervision, and clinicians should view this as an area for continued research.”