A study conducted by the Physicians Committee for Responsible Medicine (PCRM) in Washington DC, with other researchers from the Czech Republic, Italy and the US has been approved by the NHS. To gain a more accurate idea of how effective this type of dietary intervention is, more research with a wider variety of people and needs to be carried out for longer.
Despite this, the participants of the randomised controlled trial were split into two groups. One group was asked to follow a low-fat vegan diet and the other group was asked to continue with their normal eating habits. Participants of the study were aged 25-75 with BMIs of 28-40. In adults a BMI of 25 to 30 is classed as overweight and 30 or above is classed as obese.
Participants had to make their own meals without any meal plans provided. The groups were randomised, however there was not any participant who had diabetes already, was pregnant, abused alcohol or drugs, or currently eating a vegan diet.
The vegan group had vegetables, grains, legumes, fruits and carbohydrates. The results showed that there was an improved beta cell function and that lower levels on insulin were secreted between meals and greater levels secreted in response to meals. Their BMI decreased by 2 with the average BMI falling from 33.1 to 33.2 in the intervention group, and their visceral fat volume decreased from an average of 1,289cm3 to 1,090cm3 but increased in the control group that didn’t change their diets over the 16 weeks.
More studies need to be carried out to assess the effectiveness of an intervention to prevent diabetes, with more controlled factors. However, the results show that people who are overweight could potentially benefit from a low-fat benefit plant based diet in preventing diabetes.