I said "weight" not "mass". And yes, I consistently gained weight all day (water + food intake), and did not return to morning weight (minus actual fat used up,

I said "weight" not "mass". And yes, I consistently gained weight all day (water + food intake), and did not return to morning weight (minus actual fat used up, about .5 lbs a day on average) until after sleeping. I think the amount of weight lost through exhaling is minimal compared to urinating and defecation. And defecation is almost none at all. (my tests showed that bowel movements have very little affect on weight)