A randomized clinical trial has been conducted on Chinese adults with early type 2 diabetes to explore the effectiveness of an intermittent fasting meal replacement diet in controlling blood glucose levels.
The study is published in JAMA Network Open.
Study: A 5:2 Intermittent Fasting Meal Replacement Diet and Glycemic Control for Adults With Diabetes
Background
Type 2 diabetes has become a major public health crisis worldwide. According to the International Diabetes Federation report published in 2021, about 537 million adults are living with type 2 diabetes globally.
China has the highest prevalence of diabetes in the world. The country has witnessed a 56.6% increase in diabetic adults between 2011 and 2021. The current prevalence of diabetes in China is 12.4%. Moreover, about 50% of the Chinese general population is either overweight or obese.
Obesity and overweight are the major risk factors for diabetes development. It has been observed that an improvement in glycemic control and a reduction in antidiabetic drug dosage can be achieved through body weight reduction.
Meal replacement is a valuable weight loss strategy wherein a prepackaged food or beverage is substituted for one or more meals. Existing randomized clinical trials have shown that meal replacement is more effective than other diets in achieving weight loss.
In this randomized clinical trial, scientists have investigated whether a combination of a 5:2 intermittent fasting diet and a meal replacement diet can effectively control blood glucose levels and reduce body weight in obese or overweight Chinese adults with early type 2 diabetes.
The 5:2 intermittent fasting diet involves two nonconsecutive fasting days (one-fourth of the energy intake of a habitual diet) and five days of habitual intake per week.
Study design
This randomized clinical trial was conducted on a total of 405 Chinese adults with newly diagnosed type 2 diabetes who had not used any antidiabetic or weight-loss drugs in the past three months.
The participants were randomly categorized into three groups, each receiving either metformin, empagliflozin, or 5:2 meal replacement. The treatment lasted for 16 weeks.
The participants in the 5:2 meal replacement group consumed one serving of a low-energy product instead of all three regular meals for two nonconsecutive days. On the remaining five days, they consumed breakfast and lunch according to their choice but had one serving of a meal replacement product for dinner.
Parameters analyzed after the end of the 16-week treatment period included glycated hemoglobin (a measure of glycemic control), body weight, anthropometric parameters, and biochemical parameters.
Important observations
The highest reduction in glycated hemoglobin level was observed in the 5:2 meal replacement group compared to that in the metformin group and empagliflozin group. However, no significant difference in glycated hemoglobin level was observed between metformin-treated and empagliflozin-treated patients.
Except for patients aged 60 years or above, the improvement in glycemic control due to 5:2 meal replacement was observed across all participants, including obese or overweight patients.
The proportion of patients achieving glycated hemoglobin levels of less than 7% or 6.5% was significantly higher in the 5:2 meal replacement group compared to that in the metformin and empagliflozin groups.
About 76% of participants in the 5:2 meal replacement group maintained a glycated hemoglobin level of less than 6.5% at 8 weeks post-treatment. Fasting blood glucose level was also reduced by 30.3 mg/dL in the 5:2 meal replacement group.
A significantly greater reduction in body weight, waist and hip circumference, and systolic and diastolic blood pressure was observed in the 5:2 meal replacement group compared to that in the other two groups.
Regarding safety profile, the 5:2 meal replacement was found to cause constipation in one patient and hypoglycemia in 8 patients, which could be due to a low-energy diet.
In the metformin group, 26 patients experienced mild gastrointestinal symptoms, and 8 patients had hypoglycemia. In the empagliflozin group, three patients experienced urinary symptoms, five patients had hypoglycemia, and one patient reported feeling thirsty.
Severe adverse events, including severe rash and hospitalization due to increased blood ketone levels, were observed in two patients in the empagliflozin group. However, these complications resolved after treatment.
Study significance
The study finds that a 5:2 meal replacement strategy for 16 weeks can effectively improve glycemic control and reduce body weight in obese or overweight Chinese individuals with newly diagnosed type 2 diabetes.
This dietary intervention exhibits higher efficacy in managing diabetes and obesity than two antidiabetic drugs, metformin and empagliflozin.
The study was conducted on diabetic patients who were not taking any antidiabetic drugs and had a glycated hemoglobin level of less than 9% at baseline. Moreover, the study interventions were implemented for a short duration. Thus, future studies are needed to determine the long-term efficacy of a 5:2 meal replacement diet in patients receiving antidiabetic drugs and having greater baseline glycated hemoglobin levels.
Overall, the study findings suggest that the 5:2 meal replacement strategy may be an effective initial lifestyle intervention for early managing type 2 diabetes.