Effect of changes on body weight and lifestyle in nonalcoholic fatty liver disease

Background/Aims The effects of lifestyle modifications in nonalcoholic fatty liver disease (NAFLD) are incompletely defined. We aimed at determining the association of changes in body weight and lifestyle with changes in serum ALT levels. Methods We analyzed annual health checkup data from 1546 employees. Of 469 subjects with elevated ALT, we selected 348 male subjects by excluding those who had other causes of liver disease. They were followed for one year to assess the association of change in lifestyle with change in serum ALT. The 136 subjects who had ALT normalization were followed for two years to assess the association between lifestyle management and persistently normal ALT. Results In adjusted analysis, weight loss and regular exercise were significantly associated with improvement in serum ALT and increased the odds of ALT normalization, while starting smoking was significantly associated with deterioration in serum ALT. Subjects achieving ≥5% weight reduction showed improvement in serum ALT. Reduction in alcohol consumption was not associated with changes in serum ALT. Maintaining reduced weight (<5% gain) was significantly associated with persistently normal ALT. Conclusions Reducing weight by at least 5% with subsequent weight control and exercising regularly may be beneficial in treating NAFLD.