The Effect of Weight Loss Program on Overweight and Obese Females Based on Protection Motivation Theory: A Randomized Control Trial

Abstract

Background: It is especially true that prevalence of overweight and obesity is increasing worldwide and it is probably because of changes in diet and physical behavior pattern. Objectives: The current study aimed to test the effect of weight loss program on overweight and obese females based on protection motivation theory. Methods: A randomized clinical trial (RCT) was implemented in the form of single blind. In total, 150 females with overweight and obesity were randomly divided into three groups including: 1, standard program group; 2, motivation interviewing (MI) group and; 3, motivation interviewing (MI) and intention intervention (II) condition (50 subjects in each group). They participated in a randomized clinical trial, also attended a private nutrition clinic in Gorgan city (Golestan province, North of Iran) for the first time. A researcher-made questionnaire and participant’s sheets (including three days food recall and anthropometric traits) were used to collect data. Data were analyzed using SPSS (ver.11) and statistical tests including Kruskal-Wallis, One-way ANOVA, Friedman test, Tukey test, Paired T-test and linear regression model were employed. Results: The mean age of females was 38.45 ± 9.49 years, most of them had academic degree 46.7% (n = 70), 78.7% (n = 118) were married and 60.7% (n = 91) were housewives. ANOVA repeated measure test showed that daily energy intake decreased two (P = 0.001) and six months (P = 0.001), weight (P = 0.007) and body mass index (BMI) (0.005) after intervention. Threat appraisal statistically differed six months after intervention (P = 0.001). Conclusions: Motivational interviewing resulted in decreased daily energy intake, anthropometric characteristics as well as augmented scores of coping and threat appraisal.