A new study has found that people with type 1 diabetes can lose weight by switching from animal-based foods to plant-based ones—even when the plant-based foods aren’t all considered healthy.
The research, published in Frontiers in Nutrition by the Physicians Committee for Responsible Medicine, showed that participants who followed a low-fat vegan diet lost about 11 pounds over 12 weeks.
In contrast, those who followed a traditional portion-controlled diet saw no significant change in weight.
The study was led by Dr. Hana Kahleova, the director of clinical research at the Physicians Committee.
She explained that replacing animal products with plant-based foods—even those labeled “unhealthy,” such as fruit juice, white bread, and sweets—was still more effective for weight loss than eating typical animal-based meals.
For example, she noted that having orange juice and toast for breakfast led to better weight loss results than eggs and cottage cheese.
This study was a deeper analysis of a previous clinical trial, which was the first to examine the effects of a vegan diet in adults with type 1 diabetes. In the original trial, 58 adults were split into two groups.
One group followed a low-fat vegan diet with no calorie or carbohydrate limits, while the other followed a portion-controlled diet, where calorie intake was reduced and carbohydrate levels remained steady.
The researchers used a scoring system called the Plant-Based Diet Index (PDI) to track how much participants ate various types of plant-based foods.
“Healthful” plant foods included fruits, vegetables, legumes, nuts, whole grains, and tea, while “unhealthful” ones included sugary drinks, refined grains, potatoes, and desserts.
People in the vegan group increased their intake of healthy plant foods like legumes and whole grains, and slightly increased their intake of less healthy plant foods too.
However, the overall change in plant-based eating—especially the increase in healthy options—was clearly linked to weight loss.
Those on the portion-controlled diet had a small increase in whole grains but saw no significant changes in weight.
Importantly, this weight loss happened without participants needing to count calories or carbs, which can be challenging for people managing type 1 diabetes. The original study also found that the vegan diet improved blood sugar control, reduced insulin needs, and led to better cholesterol and kidney function.
In summary, this research suggests that focusing on plant-based eating—even if not perfect—can lead to meaningful health improvements for people with type 1 diabetes, especially when it comes to losing weight.
If you care about diabetes, please read studies that eating more eggs is linked to a higher risk of type 2 diabetes, and how to eat to reduce heart disease death risk if you have diabetes.
For more health information, please see recent studies about high-protein diets linked to a higher risk of type 2 diabetes, and results showing Mediterranean diet could help reduce the diabetes risk by one-third.
