looking for some advice about food Allergy Testing Methods.

I feel that food is one of the most crucial parts of our ongoing health but can also cause us unknown problems if our body does not find something agreeable.

I'm looking to find out which Method would be the best to do a broad sweep of different types of food and test accurately if I am allergic to any of them.
I have been told that the method of testing food on your back if extremely inaccurate and can give a lot of false negatives and was recommended as one not to take. I have taken an allergy test which involved a small electrical device and me holding something in my hand and the tester using a device to see which food essences was my body was reacting to negatively. I was very sceptical of that system but someone told me that this system is quite accurate.

I'm hoping that someone knows a lot about this and can point me in the right direction. I'm basically looking for a system where I can go and have my body tested for maybe 50 or 100 types of food so I know if any of them are affecting me negatively. I am having some medical problems and I feel that some of these are being made worse due to my diet.

Any help you can provide (even if it is links to other websites) would be greatly appreciated.

Thanks in advance