CLA (Conjugated Linoleic Acid) is an Omega-6 fatty acid which is found in the meat and dairy products of animals such as cows and sheep, but is not naturally produced by the human body. Conjugated Linoleic Acid is a fatty acid like that of Linoleic acid, but they have different molecular structures. Interestingly enough, although they are chemically related, it is found that they have opposite effects on the body once consumed.
Linoleic Acid has been found to stimulate lipogenesis which is the metabolic formation of fat. CLA does the opposite by inhibiting fat formation in the body. This is also why CLA is known as an anti-carcinogen as it inhibits the development of cancer by preventing tumor growth.