Comments on "The Effects of Aerobic and Resistance Exercise Training on Liver Enzymes and Hepatic Fat in Iranian Men With Nonalcoholic Fatty Liver Disease".

Dear Editor,

We read with great interest the article entitled “The Effects of Aerobic and Resistance Exercise Training on Liver Enzymes and Hepatic Fat in Iranian Men With Nonalcoholic Fatty Liver Disease” (1) the authors reported that both the aerobic (AT) and resistance (RT) exercise training significantly reduced the hepatic fat content, alanine amino transferase (ALT), and aspartate amino transferase (AST) levels in patients with nonalcoholic fatty liver disease (NAFLD). However, these results have been shown in previous studies (2-9), and we believe that the current study provides an important contribution to the literature. Therefore, we needed to point out some issues.

NAFLD is a disease that is directly related to lifestyle, so its prevalence is a consequence of the rising incidence of obesity, diabetes, and other metabolic syndrome components (10). On the other hand, it seems that lifestyle modifications and changes in the composition of the diet also play a key role in the treatment of NAFLD (10). Eating fat, saturated/trans, unsaturated fat with an emphasis on omega-3, simple sugars, fiber, processed meats and fast food play a pivotal role in prevention, improvement or worsening of this multifactorial disease. Therefore, it is important to assess the diet of patients because of its potential role in NAFLD. Changes in diet would be considered confounding factors in this study; however, the dietary intakes of the participants in this study have not been evaluated. At the same time, patients with NAFLD should receive dietary advice regarding the most acceptable therapy for their disease (10).

Moreover, it is not clear in this study whether the subjects represented new cases of NAFLD, if they had previously received any therapy, or how long they had been diagnosed with the disease.

Furthermore, according to the aim of this study, the amount of physical activity at baseline was not determined, and it is not clear if there were any differences between the three groups of patients in terms of their initial total physical activity.

Finally, we suggest that this study be revised once more so that readers of this journal can clearly understand how the effects of daily exercise improve NAFLD.