If you're trying to lose weight and feel like you could use a little help, there are lots of great diet supplements to choose from. Many of them you would never suspect!Cayenne PepperThis spice boosts metabolism by as much as 8 percent for several hours after ingestion. It does this through a process called thermogenesis.GinsengFor thousands of years, the Chinese have used ginseng root for energy and vitality. This root acts as a stimulant, adaptogen and appetite suppressant.Green TeaLike ginseng, green tea is a stimulant that boosts energy and suppresses appetite. It is also thermogenic like cayenne.