Dietary interventions that involve moderate calorie restriction (CR) are an established strategy for weight management and reducing the risk of developing type 2 diabetes. Intermittent fasting (IF), defined as a period of fasting interspersed with days of ad libitum eating, has gained popularity as an alternative to CR. However, few trials have considered applying meal timing during the ‘fasting’ day, which may be a limitation.
A new study has developed a novel intermittent fasting plus early time-restricted eating (iTRE) approach. Scientists from the University of Adelaide and the South Australian Health and Medical Research Institute (SAHMRI) have compared two diets: a time-restricted, intermittent fasting diet and a reduced-calorie diet. They wanted to determine which was more beneficial for people developing type 2 diabetes.
Senior author of the University of Adelaide’s Professor Leonie Heilbronn, Adelaide Medical School, said, “Following a time-restricted, intermittent fasting diet could help lower the chances of developing type 2 diabetes. People who fasted for three days during the week, only eating between 8 am and 12 pm on those days, showed greater tolerance to glucose after six months than those on a daily, low-calorie diet.”
“Participants who followed the intermittent fasting diet were more sensitive to insulin and also experienced a greater reduction in blood lipids than those on the low-calorie diet.”
The study involved more than 200 participants recruited from South Australia in the 18-month study. Participants on both the time-restricted, intermittent fasting diet and the low-calorie diet experienced similar weight loss.
First author Xiao Tong Teong, a Ph.D. student at the University of Adelaide, said, “This is the largest study in the world to date and the first powered to assess how the body processes and uses glucose after eating a meal, which is a better indicator of diabetes risk than a fasting test.”
“The results of this study add to the growing body of evidence to indicate that meal timing and fasting advice extends the health benefits of a restricted calorie diet, independently from weight loss, which may be influential in clinical practice.”
- Teong, X.T., Liu, K., Vincent, A.D., et al. Intermittent fasting plus early time-restricted eating versus calorie restriction and standard care in adults at risk of type 2 diabetes: a randomized controlled trial. Nat Med (2023). DOI: 10.1038/s41591-023-02287-7