Appetite is generally thought to be the desire or wish to eat food however in some people under certain circumstances or condition, people will lose their appetite. Appetite stimulant is also known as orexigenic agents. It is an agent to stimulate the desire to eat by affecting various pathways. Psychologically, the appetite stimulant will cause the person to have increased attention to food stimuli and so advance the initiation of eating or by increasing meal frequency, size or meal duration. Appetite stimulant is commonly used in conditions that causes loss of appetite leading to weight loss or muscle wasting such as chronic diseases, AIDS, and cancer. There is a certain appetite stimulant that can be added to a daily diet such as zinc, vitamin B1, fish oil. FDA-approved medications such as Dronabinol commonly used in people with HIV or undergoing chemotherapy. Megestrol frequently use for people who are cachexia due to underlying chronic condition and Oxandrolone for patients after severe trauma, infections or surgery. However, Oxandrolone has a high risk of causing atherosclerosis.