BREAKING research from the University of Adelaide and South Australian Health and Medical Research Institute (SAHMRI), Adelaide, Australia, investigated the link between diet and the risk of developing Type 2 diabetes. Researchers believe that 60% of Type 2 diabetes cases could be delayed or prevented by changes to lifestyle and diet. Thus, a time-restricted, intermittent fasting diet and a reduced calorie diet were compared to determine which was more beneficial for people prone to developing Type 2 diabetes.
The researchers created a novel intermittent fasting plus early time-restricted eating approach (iTRE), where 30% of the energy requirements were consumed between 8 a.m. and 12 p.m., followed by a 20-hour fasting period 3 non-consecutive days per week, with ad libitum eating on other days. Participants were randomised into three groups: iTRE, calorie restriction (70% of energy requirements daily, without time prescription), or standard care (weight loss booklet). The primary outcome investigated was a change in glucose area under the curve in response to a mixed-meal tolerance test performed at a 6-month follow up.
Results suggested that time-restricted, intermittent fasting could help to lower the chances of developing Type 2 diabetes, with participants randomised to the iTRE group showing a greater tolerance to glucose after 6 months (p=0.03). These participants were also more sensitive to insulin and experienced a greater reduction in blood lipids than those on the calorie restricted diet. However, side effects were highest in the iTRE group. Reports of fatigue, constipation, and headaches were highest in the iTRE group than the other groups.
Overall, prolonged fasting led to greater improvements in postprandial glucose metabolism in adults at an increased risk of developing Type 2 diabetes. Xiao Tong Teong, University of Adelaide and South Australian Health and Medical Research Institute, commented that “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,” before concluding that “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, and this may be influential in clinical practice.”