Abstract
Background: Adult zebrafish (Danio rerio) and larvae forms are being used in studies related to obesity. According to the WHO, 13% of world population were obese in 2016 and between 1975 and 2016; the prevalence of obesity has been increased 3 times. Zebrafish has been a successful model for mammalian obesity to study various obesity-induced diseases in humans.

Aims and Objectives: The objectives of the study are to create a zebrafish model of obesity and to study the effects of obesity on learning and memory using a visual discrimination test.

Materials and Methods: Twenty zebrafish of 3–6 months of age were randomly selected and divided into two groups: (1) High feed group (HFG) (n = 10) and (2) normal feed group (NFG) (n = 10). The fishes were segregated into separate pots and numbered. Specified diet plan was followed for 8 weeks in both the groups. Length, weight, and body mass index (BMI) of fishes were measured every week and noted in Microsoft Excel sheet.

Results: The HFG fishes were gaining more weight (P = 0.016) from the 5th week onward than the NFG fishes which were also evident with a significant difference in the BMI value from the 6th week (P = 0.011). However, the length did not have significant difference between the groups.

Conclusion: The simple feed protocol which has been followed was successful in creating an obesity model of zebrafish. This zebrafish obesity model created can be further used for various research studies on obesity.

Key words: Body Mass Index; Danio rerio; Obesity; Zebrafish