SUBREDDIT: r/loseit
TITLE: Question about fat density?
POST: I was in the bath tub yesterday and I was trying to explain the concept of displacement to my 3 year old, and it got me thinking.

I've read in more than once place that muscle is denser than fat and that fat weighs approximately 1.98lb per liter.

Here's the part that baffles me.

Let's say that I am overweight (I am) and that I am trying to lose a total of 60 pounds (I am - 40 to go).  I know that the weight loss won't be exclusively fat as there are other fat-supporting structures that will shrink with weight loss.  But it's mostly fat, right?

According to the 1.98lb per liter rule, that means that my body should shrink by approximately 60/1.98lb liters, which is almost *30 liters*.  There is no possible way that my body is going to shrink by 30 liters by losing that much weight.  My entire body displacement is probably only about 70 liters or so.
TL;DR: 
if fat only weighs 2lbs per liter, how can I possibly weigh as much as I do given the size of my body?