Pg 2:
http://www.habitablezone.com/space/messages/25782.html
Mark said:
"I don't see it helping you figure out that if 7.5/50 = 15 %, 7/53.8 is < 15%. Frankly, it is a waste of time to try and discuss technical details with someone who can't grasp such details. You are a fantastic source of links and often ask good questions, but your follow through sucks"

My question what was included in the 50 tonnes- what total?
Or the other side of this question is what are you including in your consumables. Are you including recycling, kitchen, etc. Or are you referring 7 tons dried beef jerky and bread:). In the link I provided they are including alot of stuff in the consumables- living space, power, air circulation, etc:
http://perso.wanadoo.fr/salotti/lifesupport3.pdf
I don't think saying that consumable would only be 15% is very meanful. You don't mention what you mean by consumables, you don't mention the crew number, the duration, or even if this is a nuclear powered rocket or using convential chemical rockets.
Now in above link they aren't trying to give all the consumables which would be needed in a Mars mission- they are simply trying to compare two different systems- but it does give some idea of what is required.
I would suggest that looking at the consumables required for ISS rather than take Z's numbers. These ISS amounts must also need to factor in not having the same resuppy which ISS has and continancy factors, such as a mission might need to abort without additional resupply from Mars surface or anything in Mars orbit. There are also number of other factors that would need to be considered.
Finally if you had said Mars Manned required 15% and Moon manned required [fill in the blank], then again it could mean something (assuming you were making a valid comparison). For instance, for simple comparison Mars: 15 months. Moon: 3 months. Travel time to Mars 180 days. Travel time to the Moon 4 days. Allow resupply for both.