Investigating metabolic changes associated with obesity in the model organism, <i>Danio rerio</i>

Obesity is a growing global epidemic and one of the leading causes of preventable death. In 2022, the prevalence of obese adults aged 18 years and older was 16%, more than doubling since 1990. These alarming levels of obesity are suggested to be major contributors to the increasing prevalence of metabolic issues, including cardiovascular disorders, type 2 diabetes mellitus, and various types of cancer. The objective of this study is to build a model using Danio rerio (zebrafish) to illuminate the effects of obesity, specifically how obesity alters metabolic rates and whether these changes reflect underlying metabolic dysregulation. D. rerio are a widely recognized model organism, sharing approximately 70% of their genetic identity with humans and possessing key organs, including the pancreas, adipose tissue, kidneys, and the liver, all of which play crucial roles in human metabolic regulation. We hypothesize that fish fed a high fat diet will result in a model of obesity and will display observable differences in both metabolic rate and behavioral movement. Zebrafish (n=36) were fed frozen Artemia and were randomly assigned to one of the two dietary groups: a control group (6 mg) or experimental group (60 mg). Body Mass Index (BMI) was monitored throughout the study to track changes associated with the dietary interventions. Standard metabolic rates were assessed using a 3D-printed intermittent-flow respirometry system, standardized with physical movements recorded and analyzed through Blender. Results note that the BMI of fish were not different before (Welch’s T-Test; p = 0.08) but were different after the study (Welch’s T-Test; p &lt; 0.05). The comparison between the mean BMI of obese and normal fish was significant (F-value = 11.38, p &lt; 0.05), with female obese fish different from the control female and control male fish ( p &lt; 0.05), and male obese fish different from the control female fish ( p &lt; 0.05). This study has shown that obese fish can be raised in 8 weeks and can be used as a model to study metabolic processes as well as genetic changes associated with obesity that may lead to human disease. This study was supported by the University of Tampa’s Office of Undergraduate Research and Inquiry (URI) Grant. This abstract was presented at the American Physiology Summit 2025 and is only available in HTML format. There is no downloadable file or PDF version. The Physiology editorial board was not involved in the peer review process.