Although ginseng has been shown to have an anti-obesity effect, anti-obesity-related mechanisms are complex and have not been completely elucidated. In the present study, we evaluated ginseng’s effects on food intake, the digestion and absorption systems, as well as liver, adipose tissue, and skeletal muscle in order to identify the mechanisms involved. A review of previous in vitro and in vivo studies revealed that ginseng and ginsenosides can increase energy expenditure by stimulating the adenosine monophosphate-activated kinase pathway and can reduce energy intake.