High fat diet and associated changes in the expression of micro-RNAs in tissue: Lessons learned from animal studies

Environment and genetic factors play an important role in the development of obesity, and diet is one of the main contributing factors to this disease. High fat intake is associated with body weight gain, leading to obesity and other metabolic diseases. MicroRNAs (miRNAs) are a group of small, noncoding RNAs that are important regulators of gene expression at posttranscriptional level. Studies have shown that high fat intake, independent of body weight status, can significantly impact both negatively and positively the expression of miRNAs and thus the biological function of tissues such as adipose, skeletal, and cardiac muscle, liver, neuronal, and endothelial. This review will summarize the effects of high calorie diet in the form of high fat intake on miRNA expression in various tissues of animal models and of high fat fed offspring. We will also briefly review the impact of different dietary lipids on miRNA expression. Given changes in miRNA expression have been associated with the development of many diseases including obesity, understanding their biological role could have important clinical implications and offer tangible therapeutic targets for the prevention, management, and/or treatment of obesity and other lifestyle‐related disorders

Intermittent fasting with or without exercise prevents weight gain and improves lipids in diet-induced obese mice

Intermittent fasting (IF) and high intensity interval training (HIIT) are effective lifestyle interventions for improving body composition and overall health. However, the long-term effects of IF and potential synergistic effects of combining IF with exercise are unclear. The purpose of the study was to investigate the long-term effects of IF, with or without HIIT, on body composition and markers of metabolic health in diet-induced obese mice. In a randosmised, controlled design, 8-week-old C57BL/6 mice (males (n = 39) and females (n = 49)) were fed a high fat (HF) and sugar (S) water diet (30% (w/v)) for 24-weeks but were separated into five groups at 12-weeks: (1) 'obese' baseline control (OBC); (2) no intervention (CON); (3) intermittent fasting (IF); (4) high intensity intermittent exercise (HIIT) and (5) combination of dietary and exercise intervention (IF + HIIT). Body composition, strength and blood variables were measured at 0, 10 and/or 12-weeks. Intermittent fasting with or without HIIT resulted in significantly less weight gain, fat mass accumulation and reduced serum low density lipoproteins (LDL) levels compared to HIIT and CON male mice (p < 0.05). The results suggest that IF, with or without HIIT, can be an effective strategy for weight gain prevention despite concurrently consuming a high fat and sugar diet