The effect of intermittent fasting on liver morphology in non-alcoholic fatty liver disease: A narrative review of animal studies and clinical trials.

One of the more serious complications of obesity, apart from the development of type 2 diabetes, is the development of metabolic liver diseases, including non-alcoholic fatty liver disease (NAFLD). Intermittent fasting (IF) is one of the best-documented lifestyle changes in the literature, quickly improving metabolism and reducing inflammation. Meal consumption, its rhythm, and timing influence the functions of many organs, including the liver, whose main function is to respond to the nutrient load that occurs after a meal. The liver is an organ that responds rapidly to changes in nutritional intake. Even a single, episodic fast lasting longer than 10 hours triggers metabolic and epigenetic changes in the liver. Most studies observed a decrease in hepatic steatosis, most often described as a decrease in the number and size of fat droplets. Only in one study was an increase in the number of fat droplets observed. No improvement in liver morphology was observed in the case of low-choline diets. In models where hepatic steatosis levels were reduced, a reduction in inflammation was also observed, including fewer inflammatory cells in the liver and a reduction in fibrosis. Fasting is responsible for altering the components used for energy production. It also alters liver metabolism in pathways responsible for lipid and cholesterol metabolism, insulin signaling, circadian rhythm, and immune function. There are several types of IF, and each has its own benefits. Differences in their courses allow tailoring the intervention to individual lifestyles and socioeconomic circumstances, helping patients to persevere with the intervention and achieve the best results. There is also a need for further research, particularly clinical trials in larger, more diverse patient groups, to determine the full potential health benefits of IF.