Effects of alternate-day fasting and time-restricted feeding in obese middle-aged female rats

• Published in: Nutrition (Burbank, Los Angeles County, Calif.) Vol. 116; p. 112198
• Main Authors: Bilibio, Bruna L. Endl, dos Reis, Welerson R., Compagnon, Letícia, de Batista, Diovana G., Sulzbacher, Lucas M., Pinheiro, Juliana F., Ludwig, Mirna S., Frizzo, Matias N., Cruzat, Vinicius, Heck, Thiago G.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01-12-2023; Elsevier Limited
• Subjects: Adipose tissue; adiposity; Aging; Animals; Biomarkers; Biometrics; Blood; Body mass index; Body size; Body Weight; Carbohydrates; Comorbidity; Diet; Energy consumption; Fasting; Female; Females; Glucose; Health promotion; Heat shock proteins; High density lipoprotein; High fat diet; Homeostasis; Hsp70 protein; Inflammation; Insulin; Insulin resistance; Insulin Resistance - physiology; intermittent fasting; Leukocytes; Lipids; Lymphocytes; Middle age; Monocytes; Nutrient deficiency; Obesity; Overweight; oxidative stress; Rats; Rats, Wistar; Triglycerides; Vagina; Weight control; weight loss; Weight reduction; United States > US; adiposity; intermittent fasting; inflammation; high-fat diet; weight loss; obesity; oxidative stress
• ISSN: 0899-9007; 1873-1244; 1873-1244
• DOI: 10.1016/j.nut.2023.112198

•Intermittent fasting reduces body weight without decreasing adiposity in female rats.•Intermittent fasting does not modify the glycemic response and lipid profile in female rats.•Time-restricted feeding has an effect on the hematologic inflammatory profile in female rats.•Alternate-day fasting has an effect on hematologic inflammatory profile in female rats.•Intermittent fasting does not modify antioxidant defenses and heat shock protein 70 in the female rat liver.
Obesity is a multifactorial condition associated with metabolic alterations that can be aggravated during female aging. Calorie restriction via intermittent fasting (IF) diets may reduce body weight and therefore have the potential to decrease obesity and associated comorbidities, such as insulin resistance. This study investigated the effects of two IF protocols, alternate-day fasting (ADF) and time-restricted feeding (TRF) in middle-aged obese female rats.
Wistar rats (age 15 mo) were fed with standard chow or high-fat diet for 8 wk and then separated into the following groups (n = 5–8 each) for another 8 wk: control (received standard chow), obese (received high-fat diet), obese + ADF (24-h fasting protocol), and obese + TRF (14 h daily).
At the end of the study, both IF protocols were able to reduce body weight and body mass index compared with the obese group. However, no changes were observed in adiposity and glucose homeostasis. We also found an increase in total leukocytes, lymphocytes, and monocytes in the TRF group and a higher number of platelets in the ADF group. Blood lipid profiles, including triglycerides and high-density lipoprotein, as well as liver stress responses, such as heat shock protein 70 and malondialdehyde, were not changed by IF.
Although ADF and TRF protocols resulted in a reduction of body weight and body mass index, these dietary interventions did not promote health benefits, such as reducing blood lipid profile, adiposity, and insulin resistance. In addition, ADF and TRF increased inflammatory biomarkers, which may increase the risk of obesity-associated comorbidities.