A randomized controlled trial of an individualized nutrition counseling program matched with a transtheoretical model for overweight and obese females in Thailand

BACKGROUND/OBJECTIVE Effective weight reduction remains a challenge throughout the world as the prevalence of obesity and its consequences are increasing. This study aimed to determine the effects of an individualized nutrition counseling program (IC) matched with a transtheoretical model (TTM) for overweight and obese subjects. SUBJECTS/METHODS Fifty overweight and obese subjects aged 19-60 years with a body mass index ≥ 23 kg/m2 were enrolled in the weight reduction study. They were randomized into two groups: Intervention group received an IC matched with a TTM; control group received an educational handbook. Body weight (BW), body fat (BF), waist circumference (WC), waist to height ratio (WHtR), stages of change (SOC), processes of change (POC), food intake, and physical activity (PA) were assessed at baseline and at 4, 8, and 12 weeks after program initiation in both groups. All data were analyzed by intention-to-treat, using SPSS software for hypothesis testing. RESULTS Forty-five female subjects were included in the 12-week trial at Ramkhamhaeng Hospital, Bangkok, Thailand. The results showed significant weight loss (1.98 ± 1.75 kg; 3% loss of initial weight) in the intervention group at 12 weeks, compared to a 0.17 ± 1.67 kg loss in the control group. There were significant differences between intervention and control groups in BF mass (-1.68 ± 1.78, -0.04 ± 1.62 kg); percentage BF (-1.54 ± 2.11, 0.08 ± 2.05); WC (-5.35 ± 3.84, 0.13 ± 3.23 cm); WHtR (-0.0336 ± 0.02, -0.0004 ± 0.02), and energy consumption (-405.09 ± 431.31, -74.92 ± 499.54 kcal/day) in the intervention and control groups, respectively. Intragroup SOC was improved in both groups. The POC for the weight management action (WMA) process was significantly different with POC scores increasing by 16.00 ± 11.73 and 7.74 ± 14.97 in the intervention and the control groups, respectively. PA level did not change in either group. CONCLUSIONS The IC matched with a TTM resulted in reductions in BW, BF, and WC, thus reducing likely health risks by decreasing energy intake and inducing positive behavior changes while enhancing the WMA process.