Weight loss, in the context of medicine, health, or physical fitness, is a reduction of the total body mass, due to a mean loss of fluid, body fat or adipose tissue and/or lean mass, namely bone mineral deposits, muscle, tendon, and other connective tissue. It can occur unintentionally due to an underlying disease or can arise from a conscious effort to improve an actual or perceived overweight or obese state.
Stomach cancer, or gastric cancer, refers to cancer arising from any part of the stomach. Stomach cancer causes about 800,000 deaths worldwide per year. Prognosis is poor (5-year survival <5 to 15%) because most patients present with advanced disease.