If you have something other than TMAU, you may be fine drinking soy milk. If you are in the US you can find rice milk at wal-mart and Martin's food stores.
I'm in the same boat as you, a bit skinny. Have you had any changes in odor since you started posting here? If I remember correctly we were doing about the same regimen at one point. I had a few days where I couldn't smell much of anything but my family could. Not much progress here. I hope you are having some success.