What would you say if I told you I could sell you an appetite-control agent that requires no prescription, has no common side effects, costs very little (ie is incredibly cheap) and is very effective?

"How much and where do I send my money?"

As I'm a nice guy, I won't take your money, instead I'll direct you to someone else who will gladly take your cash: Coca-Cola and your local water board. Yes folks, the magic elixir is WATER. Good ol' H2O.

Scientists yesterday reported results of a new clinical trial confirming that just two 8-ounce (~225ml) glasses of the stuff, taken before meals, enables people to shed pounds.
— EurekAlert

So there you have it folks, 2 glasses of water before every meal will help you lose weight and won't break the bank at the same time, unless of course you insist on drinking two glasses of this stuff 3 times a day :-)