I have a weight loss site that pulls in good visitor numbers but I don't really monetize it very well. All I have is a couple of google adsense units. The traffic is mostly from google and coming from very broad keywords, such as "weight loss". How do I get the most out of the visitors without changing the actual site content?

I heard plenty of people speaking about how much money there is in the weight loss niche, but all I am getting is $0.2 per click through adsense.