The effects of DRD2/ANKK gene polymorphisms related to food desire on mental health, eating behavior, and physical activity levels in the “fit for future” weight management program

The National Health and Morbidity Survey (NHMS) reported that Malaysia has a high prevalence of overweight and obesity, which has increased from 44.5% in 2011 to 54.4% in 2023 among adults. Factors that may contribute to obesity in Malaysia are genetics, mental health disorders, eating behavior and activity participation. Studies stated that DRD2/ANKK1 may be associated with the increase in obesity due to its role in rewarding and reinforcement mechanisms that make the person feel motivated and addicted (Hernández & Jiménez-Rodríguez, 2024). This study aims to determine how the DRD2 gene influences dietary intake, physical activity and mental health in individuals with a genetic predisposition to obesity. The study includes three phases, which are phase 1 (pre-assessment), phase 2 (intervention), and phase 3 (post-assessment). The assessment must be completed, including questionnaires, anthropometric measurements, and blood collection during phases 1 and 3. As the data were not normally distributed, non-parametric tests (Wilcoxon Signed-Rank and Mann–Whitney U tests) were employed. It showed reductions in energy and macronutrient intake (23.0% in energy, 24.5% in carbohydrate, 17.8% in protein and 24.4% in fat), pre and post, which demonstrated the intervention's positive effect. Yet there was no statistically significant association between ANKK1 genotype and physical activity. A key limitation was a 60% dropout rate from the planned 200 to 80 subjects, reducing the power of genetic association tests. Despite these constraints, the study presents preliminary evidence of gene–lifestyle interaction and highlights the importance of repeated measurement and adequate sample size in behaviour-genetic studies in the future.