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Obesity is a chronic multifactorial disease characterized by excess adiposity. Adipose tissue hypertrophy favors lipid deposition in ectopic tissues, such as the liver, which favors the development of the metabolic dysfunction-associated fatty liver disease (MAFLD), characterized by excessive accumulation of lipids in the cytoplasm of hepatocytes (fatty liver). Triglyceride overload in hepatocytes observed in obesity is associated with inflammation and insulin resistance status. Non-pharmacological strategies, such as the practice of physical exercise, seem to be an effective in reducing inflammatory markers and improving insulin sensitivity in obese individuals with MAFLD attenuating hepatocellular steatosis. Thus, this review aims to demonstrate the factors involved in the development of hepatic steatosis, as well as investigate the impact of physical exercise on insulin sensitivity and inflammatory markers in the condition of obesity-associated MAFLD.

There are evidence that obese-resistant animals are more physically active, due to a higher rate of lipid oxidation. Efficiency in such pathways can favor greater spontaneous physical activity and, consequently, less body fat deposition. The aim of study was characterizing the nutritional profile and spontaneous physical activity in the condition of Resistance to Obesity (OR). Wistar rats were randomized into standard diet (SD; n = 50) and high-fat diet (HFD; n = 50) groups, after obesity induction, were redistributed into Control (C), False-control (FC), Propensity to obesity (OP) and OR, and then spontaneous physical activity was evaluated. Analyzed parameters: body mass (BM), epididymal (EF), retroperitoneal (RF), visceral (VF) and respective summations (∑), adiposity index (AI), nutritional, morphological, biochemical and metabolic parameters and protein quantification. The comparison of the groups was performed by ANOVA one or two factors, with 5% significance adopted. OP and FC presented high final MC values compared to C and OR. OR had lower EF, RF, VF, ∑ and IA compared to OP. OR had similar values to C and higher HDL than FC and OP. In GTT, OR and C presented similar values and both were lower than OP in the 30 minutes. OP promoted higher values than C for glycemic AUC. OR had higher PPARγ content than C and OP, as well as levels similar to C for leptin and insulin. Spontaneous physical activity did not differ between groups. The results were not enough to show that OR animals have greater lipid oxidative capacity, as well as greater spontaneous physical activity.