Dieting is a difficult subject. That being said, the goal of your diet is really the key -- are you trying to lose weight or are there other concerns (for example gaining muscle mass). Regardless, it is a complex and difficult process. I would recommend that you discuss this with your primary care doctor
. He or she can put you in touch with a registered dietician
-- an expert in diets. Together, they can help you develop a feasible, successful and healthy diet.
There are numerous diets on the market, all with fancy names, books and devices. Most of these are designed to lose weight. Unfortunately, the data behind these working is minimal at best. People often loose weight 6 months after starting the diet (5-10 lbs) but at one year the weight is back. Essentially this is because these "fad" diets are not sustainable and some are even unhealthy.
What you need are changes that are sustainable for life. The biggest fundamental concept to understand is that weight loss
is an energy balance -- you need to consume less energy (measure in calories) than you expend (by exercise etc). In all the studies done, the biggest factor for a successful diet is portion control.
Please talk to your doctor.