Effect of a dietary-induced weight loss on liver enzymes in obese subjects

Weight loss was shown to be associated with improvements in liver enzymes and improvements of nonalcoholic fatty liver disease. However, some evidence also shows that liver enzymes may transiently increase immediately after a dietary-induced weight loss.

The aim was to assess the outcome of liver enzymes after a low-calorie diet (LCD) as well as during a follow-up period and to identify predictors for potential changes in these liver enzymes.

In this post hoc analysis of an existing database, liver enzymes were assessed before and immediately after a highly standardized soy-based meal replacement LCD providing 800 kcal/d, as well as 32 and 60 wk after the end of the LCD.

Data emanating from 147 obese subjects (104 women and 43 men) without known hepatic disease were included in this study. The LCD led to a median weight loss of 12.1 kg (range: 7.7-27.6 kg). In men, a significant decrease in alanine aminotransferase (ALT) and aspartate aminotransferase (AST) was observed immediately after the LCD, whereas, in women, these enzymes increased significantly, although mildly; however, this increase was transient. Sex was the only identifiable predictor of these changes in liver enzymes.

This study showed that mild, transient increases in ALT and AST values can be observed immediately after an LCD in women, but not in men. These changes are probably of multifactorial origin and may be considered as benign as long as they remain transient.