Dian Aristia Rachmayanti, Purwo Sri Rejeki, Raden Argarini, Hermina Novida, Sri Soenarti, Shariff Halim, Chy’as Diuranil Astrid Permataputri, Sheeny Priska Purnomo
Background: Obesity is a metabolic condition that may impair insulin sensitivity and disrupt glucose homeostasis. Since insulin and glucose affect insulin-like growth factor-1 (IGF-1), disruptions in this axis may elevate the risk of chronic diseases. Intermittent fasting (IF) modulates metabolic parameters, but the impacts on glucose regulation and IGF-1 remain underexplored. This study aimed to assess the short-term effects of two IF types, time-restricted feeding (TRF) and alternate-day modified fasting (ADMF), on fasting blood glucose (FBG) and IGF-1 in obese young women. Methods: A quasi-experimental pretest–posttest control group design was conducted over 20 days. The 31 subjects were allocated into ADMF (n = 10), TRF (n = 11), and Control (n = 10). After excluding dropouts and outliers, the final sample consisted of 22 subjects (ADMF = 7, TRF = 8, Control = 7). FBG and IGF-1 serum were measured pre- and post-intervention. Results: The FBG post-intervention significantly increased in TRF (p = 0.001) and ADMF (p = 0.036) groups, but not in Controls. Only the TRF group showed a significant reduction in IGF-1 levels (p < 0.001). Nevertheless, the ADMF group exhibited substantial decreases in body weight (p = 0.047) and visceral fat (p = 0.017). Conclusions: A 20-day IF in obese young women induced distinct metabolic effects: TRF lowered IGF-1, ADMF reduced adiposity, and both regimens increased FBG. These findings suggest that early changes in glucose regulation are highly dependent on the specific dietary regimen used. Specifically, TRF predominantly influences endocrine regulation (IGF-1 axis), while ADMF favours adiposity reduction. The concurrent rise in FBG may reflect a transient shift in glucose homeostasis during the early stages of fasting. © 2025 by the authors.
Master Program of Basic Medical Science, Faculty of Medicine, Universitas Airlangga, East Java, Surabaya, 60132, Indonesia; Faculty of Medicine, Universitas Pembangunan Nasional “Veteran” Jawa Timur, East Java, Surabaya, 60294, Indonesia; Physiology Division, Department of Medical Physiology and Biochemistry, Faculty of Medicine, Universitas Airlangga, East Java, Surabaya, 60132, Indonesia; Division of Endocrinology, Diabetes and Metabolism, Department of Internal Medicine, Faculty of Medicine, Universitas Airlangga, East Java, Surabaya, 60131, Indonesia; Geriatric Division, Department of Internal Medicine, Faculty of Medicine, Brawijaya University, East Java, Kota Malang, 65145, Indonesia; Faculty of Health Sciences, University Technology MARA (UiTM) Pulau Pinang, Bertam Campus, Kepala BatasPulau Pinang, 13200, Malaysia; Faculty of Medicine, Petra Christian University, East Java, Surabaya, 60236, Indonesia
