The Efficacy of Intermittent Fasting in Weight Reduction in Non‐obese and Obese Rats

Abstract

Obesity is a major contributing factor in the development of many chronic conditions such as type 2 diabetes and hypertension. Intermittent fasting (IF) isa pattern of feeding that cycles between periods of fasting and eating. It allows eating within a specific time period, and fast during the rest of the day. Intermittent fasting appears to be a promising approach to prevent or reverse obesity. Our project involved the induction of obesity using a high fat diet (HFD; D12492‐60% kcal diet) in male Sprague Dawley rats. Blood glucose and ketone levels were measured twice a week and daily body weights were monitored. The rats being fed on the HFD gained 12% more weight than those on a standard diet (SD) and 14% weight gain compared to the growth chart of the animal supplier within seven weeks of feeding this special diet. Blood ketone and glucose levels remained unchanged between these groups. The animals with HFD, now referred to as the obese (OB) group and those with SD referred to as non‐obese (non‐OB) rats were placed on IF next. Intermittent fastingin this experiment was designed to allow animals to eat for 6 hours during their nocturnal window of time and fast during the remaining 18 hours. The OB and non‐OB groups were subdivided into five groups during the IF study: (1) OB rats on IF who were given HFD (OB‐IF‐HFD; N=3), (2) OB rats on IF given SD (OB‐IF‐SD; N=3), (3) OB rats maintained on HFD ad libitum (OB‐non‐IF; N=4), (4) non‐OB rats on IF with SD (non‐OB‐IF; N=3), and (5) non‐OB rats maintained on SD ad libitum (non‐OB‐non‐IF; N=3). Within three weeks of exposure to IF, there was a significant (p<0.05) decrease in body weight in the IF groups compared to the non‐IF groups receiving food ad libitum. However, blood ketone levels were significantly increased in the non‐OB‐IF rats compared to non‐OB‐non‐IF group, blood glucose levels were significantly decreased. A significant decrease in blood glucose levels was also noted in the OB‐IF‐SD group compared to OB‐non‐IF animals. This study suggests that HFD induces obesity as measured by body weight in approximately seven weeks, which can be reversed by subsequent practice of IF for three weeks but depends on the nature of the diet being used during IF i.e., IF‐induced weight loss with HFD is significantly less than with SD.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.