Diet plates are based on sound basic nutritional advice. Many years ago nutritionists were asked to devise an easy to use portion control device, the plate and the food pyramid were just 2 of their solutions.
If you have problems weighing food and counting cals etc etc it probably is worth trying out the plate. But why spend the cash on a purpose made one when it is really easy, and you learn more, by making one for yourself?!?!?!
For the commercial, for sale diet plate you could go to
http://www.hsionline.com/products/ec...2/item6471.htm
But you could get a whole load of FREE info from the American Institute for Cancer Research
http://www.aicr.org/nap2.htm
This site has great visuals, it's free and wonderful, it also has the food pyramid:
http://www.warburtons.co.uk/educatio.../balanced.html
I would suggest that you have a look at these sites and read up all you can. Then buy a plain white 11 inch plate and divide it up with an indelible pen! Cheaper and easy to replace when your best mate 'borrows' it!!
I hope this is the kind of info you wanted - I really enjoyed the search I made for it - all those weird sites!!!!!!!!!!!