The Relationship of Leptin, Obesity, and Exercise: A Systematic Review

Obesity and obesity-related diseases have become a rapidly increasing important health problem. Hormones such as leptin, ghrelin, obestatin, and nesfatin-1 play an important role in fat tissue accumulation and the appetite mechanism. Leptin belongs to a class of hormones known as adipocytokines, which play a role in regulating energy metabolism. This study aimed to investigate the relationships between leptin, obesity, and exercise. This study analyses the relationship of leptin, obesity, and exercise using the Preferred Reporting Items for Systematic Reviews. We conducted this systematic review following the PRISMA 2020 statement. The systematic review used a search to identify studies published in PubMed, Wiley Online Library, EBSCO, Science Direct, and Web of Science databases. In this study, the relationships between leptin, obesity and exercise were investigated. A total of 1022 records were initially scoped in the literature search, 784 of which were duplicates. After screening for eligibility and inclusion criteria, 57 articles were ultimately included in the study. Hormones, which are thought to be the source of obesity, are the focus of current studies. Studies have shown that maintaining certain circulating leptin concentrations is essential. Studies have shown a positive relationship between leptin levels and serum fasting insulin and insulin resistance in obese individuals. It also shows that insulin resistance is associated with leptin and adiponectin. There are studies showing that exercise decreases leptin concentration. The discrepancies in the results of studies examining the effect of exercise on the leptin response may arise from many methodological differences, such as the intensity, duration, frequency, and scope of exercise, the nutritional status of the participants, and the time and frequency of sampling. This review shows that chronic exercise interventions consistently reduce leptin concentrations, mostly mediated by fat mass loss. Acute effects are inconsistent and often delayed. Prolonged strenuous exercise leads to marked decreases. Future research should standardize leptin measurement, incorporate biomarkers such as soluble leptin receptor and adiponectin, and explore leptin-targeted therapies in obesity treatment.