Abstract
In recent years, nutrition has become increasingly important in treating and managing gestational diabetes mellitus. The Health Belief Model (HBM) is a conceptual framework in health behavior research used in some medical research. The present study aimed to evaluate the effect of glycemic index training based on the HBM on metabolic indicators and pregnant women's health-related quality of life. In this open-label, parallel-controlled randomized trial, 90 pregnant women from primary health centers in Iran were recruited and randomly assigned to either the intervention group or the control group, using a block randomization method with a block size of six. The intervention group underwent 12 weeks of nutritional education on the glycemic index and load of foodstuff. The control group only received routine health care. Valid and reliable questionnaires included demographic and prenatal information, physical activity, three days of food records, quality of life (SF-12), and HBM constructs. Fasting blood samples were taken at baseline and end of the study, to assess fasting blood glucose (FBS), fasting insulin, hs-CRP, and lipids. Eighty-four pregnant women with an age mean of 30.12 ± 4.35 completed 12 weeks of intervention. At baseline, there were no significant differences between groups in the HBM subscales (P > 0.05). However, within the intervention group, there was an increase in perceived susceptibilities (mean change 1.45 ± 4.21; P = 0.03) and cue to action (mean change: 1.22 ± 3.38; P = 0.02). In the adjusted model, the General Health subscale of Quality of Life showed a significant increase in the comparison between groups (mean change 13.69 ± 29.83 vs. 0.00 ± 29.58; P = 0.04). Additionally, the adjusted model revealed a notable difference between the groups in serum hs-CRP level, (mean change -0.877 ± 3.47 vs. -0.067 ± 3.40; P = 0.01) and triglyceride level (mean change - 55.24 ± 111.21 vs. 40.92 ± 142.01; P = 0.001). However, in the adjusted model, the total cholesterol levels increased between groups (mean change 22.75 ± 66.17 vs. 30.12 ± 61.33; P = 0.01) at the end of the study. There was no significant difference in glycemic indices (P > 0.05). Participation in a nutrition education program might positively impact nutritional beliefs, behaviors, and some biochemical indicators among pregnant women. Future studies with larger sample sizes and longer follow-ups are warranted.Trial registration number: IRCTID: IRCT20190227042858N1. Registration date: 2019-07-18.