Background
Excess body weight is a common manifestation in adults with type 2 diabetes (T2D), which associated with non-optimum glycemic control. While the use of meal replacement therapy (MRT) to induce weight loss and improve glycemic control is recommended as part of the medical nutrition therapy (MNT), its feasibility remains unclear especially from the Asian perspective. 

Aim
This study aims to determine the effect of 12-weeks of MRT on body weight and glycemic control in obese T2D adults.

Method
We recruited a total of 32 participants (mean; age = 46.4 ± 8.2 years old, female = 34.4%, body mass index (BMI) = 31.8 ± 4.9 kg/m2, HbA1c = 8.8 ± 1.5%, duration of T2D = 5.0 ± 4.1 years) from National Diabetes Institute (NADI). They were randomly assigned to receive the MRT (n = 16) or conventional dietary intervention (n = 16) for 12-weeks study. MRT and conventional participants received the MNT from a researcher and a NADI's dietitian, respectively. The prescriptions designed as iso-caloric. Participants in the MRT group were asked to replace their two meals with two meal replacements in a day. Body weight and glycemic control were assessed at baseline, 6 and 12-weeks of the study. Data presented based on intention-to-treat analysis.

Results
A total of 27 participants completed the study providing 84.4% responses rate (MRT = 14, 87.5%; Conventional = 13, 81.3%). Baseline characteristics were comparable between groups. At 12-weeks, MRT group had a significant reduction in body weight (83.3 ± 13.0 kg, Δ baseline = -3.5 ± 0.5 kg) than the conventional group (87.2 ± 20.8 kg, Δ baseline = -1.1 ± 2.4 kg; p < 0.01). The percentage of weight loss in MRT (-4.1 ± 2.1%) was significantly larger than the conventional group -1.4 ± 2.5%; p < 0.01). A significant improvement in BMI and percentage of body fat were also observed in MRT group as compared to the conventional group. Although generally the differences between groups in HbA1c were not significant, we attained significant differences between both groups (p = 0.006) in HbA1c after excluding confounders effect of the participants who had changed the types of OAD. Within MRT group had reduced HbA1c level from 9.1 ± 1.5% at baseline to 7.9 ± 1.2% at 12 weeks (Δ baseline = -1.1%; p < 0.01), which were not observed in the conventional group (baseline = 8.5 ± 1.5%; 12 weeks = 8.0  ± 1.1%; Δ baseline = -0.5%; p = 0.11). About 72.5% of the participants in the MRT group adhered to meal-replacement intervention. The adherence to MRT was significantly correlated with percentage of weight loss (r = -0.70, p = 0.002), visceral fat (r = -0.54, p = 0.033) and HbA1c (r = -0.60, p = 0.015).


Discussion
The used of meal replacement therapy induces larger weight loss, BMI and percentage of body fat than the conventional dietary intervention at 12-weeks. In general, the improvement in HbA1c was not significant between groups, but removing confounding effect of diabetes medication had produced significant in differences between groups. Within the MRT group was evident in HbA1c reduction (> 1%). The high adherence rate demonstrated the feasibility of meal replacement implementation in Asian adults with type 2 diabetes. The adherence to MRT was significantly associated with the weight loss, visceral fat reduction and HbA1c reduction. A future study with a longer-term trial is warranted.

Effect of meal replacement therapy on body weight and glycemic control in obese type 2 diabetes adults: Asian experience