LOW CALORIE DIET USING LIQUID MEAL REPLACEMENTS VERSUS CONVENTIONAL FOOD FOR WEIGHT LOSS IN OBESE MALAYSIAN ADULTS WITH TYPE 2 DIABETES IN AN OUTPATIENT CLINIC SETTING

Abstract

Introduction: Little is known about the utility of meal replacements to manage obesity in Malaysians with diabetes. This study investigated the use of a low calorie diet, incorporating liquid meal replacements versus using conventional food, on weight loss in Malaysian adults with Type 2 Diabetes and obesity in an outpatient clinic setting over a period of 12 months. Methods: In this single-centre non-blinded study, 70 subjects (women: 68.6%; mean + SD age: 47.5 + 9.5 years; mean + SD Body Mass Index: 32.7 + 3.6) were randomized into one of three isocaloric low calorie diet groups: MR1 (n=20); MR2 (n=30); CD (n=20). In Phase 1 (Baseline to 6-months), the intervention differed across groups by use of MR: MR1 – one MR/day; MR2 – two MR/day; CD – conventional food only. In Phase 2 (6-months to 12-months), all groups followed a conventional food only low calorie diet. Primary outcomes were changes in weight and waist circumference. Secondary outcomes were changes in glycaemic control, lipid profile, blood pressure, and energy/macronutrient intake. Dietary challenges encountered in Phase 1 were also assessed. Results: Subjects who completed both Phase 1 and 2 (MR1: n=11; MR2: n=9; CD: n=11) were included for analysis. There were significant baseline differences between the study groups (body weight, BMI, waist circumference, and blood pressure) that did not have significant effect on change in primary outcomes over time and adjustments for these covariates were not preformed. From baseline to 6-months, mean + SE weight change (kg) (MR1: -1.6 + 0.6; MR2: -3.8 + 0.9; CD: -2.4 + 0.6) was not significant between groups but significant within MR2 and CD. Mean + SE waist circumference change (cm) (MR1: -1.9 + 0.9; MR2: -3.5 + 1.0; CD: -2.3 + 1.0) was not significant between groups but significant within MR2. The MR2 group had the highest proportion of subjects who achieved a weight loss of > 5% from baseline (MR1: 14.3%; MR2: 40.0%; CD: 16.7%). Among the meal replacers, the median + IQR number of MR sachets consumed/day was significantly higher in subjects who achieved (1.0 + 0.4) than subjects who did not achieve (0.6 + 0.9) > 5% weight loss. Change in both fasting blood glucose and HbA1c was not significant between groups. Mean + SE fasting glucose change (mmol/L) (MR1: 0.2 + 0.5; MR2: -2.8 + 0.7; CD: -1.5 + 0.6) was significant within MR2, while HbA1c change (% point) (MR1: -0.5 + 0.2; MR2: -0.6 + 0.83; CD: -1.0 + 0.3) was significant within CD. No significant change was seen in lipid profile and blood pressure between and within all groups. Mean + SE energy intake change (kcal/day) (MR1: -426 + 112; MR2: -515 + 157; CD: -463 + 129) was not significant between but significant within groups. No significant macronutrient intake change was seen between groups. Mean + SE carbohydrate intake change (g/day) (MR1: -61.7 + 13.0; MR2: -65.5 + 17.2; CD: -35.2 + 23.2) was significant within MR1 and MR2 while fat intake change (g/day) (MR1: -20.1 + 7.5; MR2: -24.8 + 9.2; CD: -31.8 + 6.4) was significant within CD. No significant change was seen in protein intake within all groups. At 12-months, only MR2 maintained a mean + SE weight change of -2.3 + 0.7 kg. Recidivism at 12-months was seen in all other outcomes within all groups. Irrespective of groups, subjects faced similar challenges with hunger, dietary deprivation, social support, need for constant care, food planning, and life complications. Challenges specific to meal replacement use were taste fatigue and unsuitability of the regimen or meal replacement product. Conclusion: With low calorie diets in adults with obesity and Type 2 Diabetes, there was no difference between the use of meal replacement and conventional food for weight and energy intake reduction. However, subjects in the MR2 group had better weight loss (6-months) and weight maintenance (12-months) when compared to MR1 or CD. Among the meal-replacers, increased compliance to the meal replacement regimen was associated with greater weight loss. During energy intake restriction, use of meal replacement produced compensatory reductions in carbohydrate intake while use of conventional food produced compensatory reductions in fat intake.