Most simply put, the definition of weight loss is to decrease in body weight. This can be due to loss of fluid, fat, tissue or lean mass. Weight loss may be voluntary or involuntary.
According to the CDC (Centers for Disease Control and Prevention), we are getting fatter, not thinner. The weight loss industry is worth $66 billion in 2017, according to the U.S. Weight Loss & Diet Control Market. Consumers continue to use commercial diet chains and the market is moving to both commercial and retail arenas.
To learn more about surgical weight loss, check out this article: What is Bariatric Surgery: Definiton & Overview