<![CDATA[Abstract. Advances in technology and the ease of performing physical activities have led to sedentary behavior. Low physical activity and a high-fat diet contribute to metabolic disorders, including changes in pancreatic structure. Non-pharmacological lifestyle interventions are becoming a trend, such as intermittent fasting. This study aims to analyze the effect of intermittent water fasting on the diameter of Langerhans islet cells in the pancreas of mice (Mus. Musculus L.) fed a high-fat diet. This study used a post-test only control group experimental design with 28 paraffin tissue samples from the pancreas from a previous study. The samples were divided into four treatment groups based on a combination of fasting and diet type. The pancreatic tissue was stained with Hematoxylin-Eosin and observed under a light microscope. Data analysis was performed using the Kruskal-Wallis test with a 95% confidence level. The results showed that there were no significant differences in the diameter of islets of Langerhans between treatment groups (p>0.05). Intermittent water fasting for 30 days with a duration of 14 hours per day did not have a significant effect on the number and diameter of islets of Langerhans. Thus, intermittent water fasting has not shown evidence of a decrease in the diameter of islets of Langerhans in mice fed a high-fat diet, which is related to the limited duration of the intervention, even though previous studies have shown a decrease in cholesterol levels. Abstrak. Perkembangan teknologi dan kemudahan melakukan aktivitas fisik mengarah kepada perilaku sedentari. Aktivitas fisik yang rendah dan diet tinggi lemak berkontribusi terhadap gangguan metabolik, termasuk perubahan struktur pankreas. Intervensi pola hidup nonfarmkologis sedang menjadi tren seperti puasa intermiten. Penelitian ini bertujuan untuk menganalisis pengaruh puasa intermiten air terhadap diameter sel Islet of Langerhans pankreas mencit (Mus musculus L.) yang diberi pakan tinggi lemak. Penelitian ini menggunakan desain eksperimental post-test only control group dengan 28 sampel blok parafin jaringan pankreas dari penelitian sebelumnya. Sampel dibagi menjadi empat kelompok perlakuan berdasarkan kombinasi puasa dan jenis pakan. Jaringan pankreas diwarnai dengan Hematoksilin-Eosin dan diamati di bawah mikroskop cahaya. Analisis data dilakukan menggunakan uji Kruskal-Wallis dengan tingkat kepercayaan 95%. Hasil penelitian menunjukkan bahwa tidak terdapat perbedaan yang signifikan pada jumlah dan diameter Islet of Langerhans antar kelompok perlakuan (p>0,05). Puasa intermiten air selama 30 hari dengan durasi 14 jam per hari belum memberikan pengaruh bermakna terhadap diameter Islet of Langerhans. Dengan demikian, puasa intermiten air belum menunjukkan bukti adanya penurunan diameter Islet of Langerhans pada mencit yang diberikan pakan tinggi lemak, yang berkaitan dengan keterbatasan durasi intervensi meskipun penelitian sebelumnya menunjukkan penurunan kadar kolestrol.]]>
