Effect of Motivational Interviewing on Dietary Intake and Weight Changes Among Preconception Women With Overweight and Obesity: A Randomized Controlled Trial

The present study was conducted to investigate the effect of motivational interviewing (MI) on dietary intake and weight changes among preconception women with obesity and overweight.

This randomized controlled trial was conducted on 70 overweight and obese women (body mass index ≥25) within the age range of 18-35 years in the preconception period referred to health centers in Tabriz, Iran. Twenty-four-hour food records were completed by women for 3 days and participants’ weights were measured before and 8 weeks after the intervention. Using a random block design and the allocation ratio of 1:1, the participants were divided into MI (6 sessions of training and MI) and control (routine preconception care) groups. The criterion for the primary outcome was the mean macronutrient intake 8 weeks after the intervention. All analyses were done according to intention to treat method.

At the baseline, there was no statistically significant difference in terms of the mean of daily energy intake, carbohydrates, fat, protein, and weight (P>0.05). After the intervention, the mean (standard deviation) of daily energy intake was 1841.3 (567.8 kcal) and 2131.0 (568.7 kcal) in intervention and control group, indicating a significant difference between the 2 groups with an adjusted mean difference (AMD) of -334.3 and a 95% confidence interval (CI) of -667.2 to -21.5 (P=0.03). However, there was no difference between the 2 groups in terms of macronutrients (P>0.05). After the intervention, the mean (SD) of participants’ weight was 74.4 (6.94 kg) and 75.7 (7.82 kg) in intervention and control groups, which demonstrated a significant difference between the 2 groups (AMD = -1.30 kg, 95% CI = -2.09 to -0.51, P=0.002).

MI is an efficient method of weight loss and the energy intake change can help preconception women with obesity or overweight to safeguard themselves against the adverse consequences of their pregnancy.