I remember writing about this a long time ago, and I found the graphic I made to illustrate it, so I thought I would go ahead and write a post about it.
First off, if you're pre-op, I would suggest you take photos. Find a nice plain background, and get someone to snap four pictures of you. If you feel able, I suggest that you do it naked, because you want to be able to see the difference in your SIZE and clothing is good at hiding details. If you can't bring yourself to do the naked, try to at least get one in bra and panties (or just boxers or briefs if you're a man). The more clothing you wear, the less clear your changes will be. Against the plain background, do front, back, right side, left side. Also, measure yourself. When I measured, I measured my neck, upper arm girth, waist, hips, breasts, upper thighs, calves and recorded them with my weight.
Now sometimes as you lose weight, you'll hit a "stall" .... a period of time where the stoopid
scale won't move. BUT something you can do while the scale is being stubborn, is take photos. I took photos every month for the first year. And I took measurements and sometimes the measurements changed MORE on the months when the weight loss seemed LESS.
I began to wonder, how can you change your dimensions when you aren't changing your weight? Especially if you're like me and don't exercise (at all).
My theory is what I call the Swiss Cheese Theory:
Prior to losing weight, our fat might be like a good solid block of Monterey Jack cheese. When we lose weight some of the fat cells have to sacrifice all that stored energy because the food intake isn't enough to balance out the calories needed. But the body doesn't just choose the "edges" of a block of fat to empty out the fat cells. It chooses a random selection of fat cells throughout the fatty tissue. Then your body gets to a point where it wants to deal with this new reality. Since your fat tissue now suddenly resembles Swiss Cheese, your body says, "Well, I guess we're not going to be able to store anything any time soon, so let's consolidate" and so your tissue sort of collapses in on itself, filling in the gaps or holes until your fat tissue no longer looks like swiss cheese. The amount of fat tissue is the same, but it takes up less space.