<![CDATA[Obesity among university students requires weight management strategies that are simple and applicable to daily life. Observing the voluntary (Sunnah) fast on Mondays and Thursdays is a potential approach, yet evidence regarding its impact on body weight remains inconsistent. This study aimed to analyze differences in weight change between obese university students practicing the Monday–Thursday fast and a control group. A pretest-posttest control group design was employed involving 12 male students (Class of 2022) from the Faculty of Medicine at Universitas Muhammadiyah Sumatera Utara, with six respondents in each group. The intervention lasted four weeks. Weight change was calculated as the difference between posttest and pretest measurements and compared between the intervention and control groups using an Independent Samples t-test following a Shapiro-Wilk normality test. The intervention group experienced an average weight loss of 4.083 ± 1.889 kg, whereas the control group showed an average weight gain of 1.667 ± 2.338 kg. The difference in mean weight change was 5.750 kg (t = −4.685, df = 10, p = 0.001). The findings indicate a significant difference in weight change between the two groups after the four-week intervention. However, these results should be interpreted with caution due to the small sample size and the lack of complete comparability regarding baseline body weight between the groups. Further research with larger samples, more comparable groups, and longer observation periods is needed to confirm these findings. ]]>
