A new study from the University of Canberra has found that low GI diets are not effective for overweight and obesity in people with diabetes.
The research, conducted by Adjunct Professional Associate, Kerry Mills, from the Centre for Research in Therapeutic Solutions, investigated whether low GI (Glycaemic Index) diets reduced body weight or markers of blood glucose in children, adolescents or adults with overweight or obesity.
Dr Mills said the theory behind a low GI diet was that if a person ate low GI foods, for example lentils, they felt fuller for longer, did not get hungry as quickly, and therefore did not eat as much.
“To test the hypothesis, we conducted a systematic review and meta-analysis of randomised controlled trials comparing low GI diets with other diet types,” Dr Mills said.
“The analysis included 101 studies involving over 8,500 participants and looked at groups within the overall cohort such as the type of control diet, blood glucose control, baseline body mass index (BMI) and dietary GI.”
He said the study found that a low GI diet had limited effect, except in people with normal blood glucose levels, in whom moderate weight loss was recorded.
“The study showed that low GI diets had no effect on weight loss in those participants who had a compromised insulin system or impaired glucose tolerance, or type 2 diabetes,” Dr Mills said.
“This surprising result may be a consequence of the fact that people with impaired insulin sensitivity continue to feel hungry even when their blood insulin levels are high — a situation that would normally lead to a feeling of satiety.”
He said it was clear from the study that a low GI diet was not effective in the case of obesity or overweight where type 2 diabetes was present, drawing the conclusion that it was not an effective solution for weight loss in these patients.
