The present invention addresses the problem of providing a composition for preventing or improving the deposition of fat in the liver, irrespective of an alcohol intake history of a level such that alcohol intake is not the cause of liver disease. The inventors discovered that glutathione has an effect for preventing or improving fat deposition in the liver that is not caused by alcohol, thereby perfecting the present invention. In particular, the present invention is effective when nonalcoholic fatty liver disease is not treated early or when no treatment is conducted for another disease.本案之課題為提供即使酒精攝取量未達到成為肝臟疾病原因之程度的酒精攝入史，預防、改善脂肪沉積於肝臟的組成物為課題。 本案發明者們發現麩胱甘肽對並非酒精所導致之於肝臟的脂肪沉積具有預防、改善的效果，而完成了本發明。尤其本發明係於非酒精性脂肪肝疾病中，在治療初期或未進行其他疾病之治療時有效。
