Not necessary, but good idea. I once thought I was eating enough and when I crunched the numbers realized I was about 1000 cals. short. Do it religiously for about a month and once you know, physically, how much you are eating you can check it periodically.
"There's nothing wrong with being a large mammal." - Val Kilmer as Jim Morrison - The Doors (1991)
Sergey Krastio Trelawny