Purely a curiosity question, but has anyone ever seen anything discussing the physical amount of food a person needs in a day?

I've just got to pondering this as I've just eaten far too much for dinner :p and it occurs to me that there's so much emphasis on calories and the like but I've never seen any on the actual amount of food to eat.  With pets it's almost always the amount - my ratty boys get 20g food a day each, give or take, and the dogs between 200 and 700g dry a day (more for Rem now he's on homemade).  My cats used to get 200g wet food a day, and the mice got around 4-7g each a day.

So why is it different for people?  Where's the site that says people need so many kilos of food a day?  And can you tell I'm finding reasons not to clean? :D

you are talking complete food though, because humans eat such a variety you couldnt possibly do it by weight. 

Something like this?

I just had a quick glance at that pyramid - it says 6 to 11 servings of bread/grains...isn't that an awful lot? So a portion of grain based cereal for brekkies and some pasta for tea leaves you with 9 slices of toast through the day :D

lol, must admit I didn't have a very good look. Does seem a lot doesn't it!

That's the whole basis of The Zone diet that was popular a few years back. You calculated what your lean body mass was and ate the right amount of protein, carbohydrates, and fats to sustain that mass. Of course activity level played a role.

Well you know it's funny but I've just started a diet that says you can eat what you want when you want and you just eat when you're hungry and stop when you're full.  Doesn't seem like it would work does it???  But having had a dog for 4 years that doesn't eat anything when he obviously doesn't want it and scoffs when he does, he's managed to maintain the same weight for 4 years.  I've lost 1lb in one day so far (I know, big deal :)) but I'll keep you posted.

CG

Is that the Paul McKenna plan?  I tried that when it first aired on TV in Jan 2006.  I think my appetite's a little too big for it, I had real trouble with the stopping part :D