It's a frame of mind.  "Thin Within" doesn't refer to "losing weight".  They call it "releasing weight".  The thought being that if you "lose" something, you might find it again.  (And I HAVE found my lost weight again).

When you lose your keys, it means a lack of attention, carelessness.  The object of your search may be right under your nose, waiting for you to pick it up again.

When you "release" something, you let it go.

I'm thinking of those kids' movies where a baby wild thing is found by a family and raised to adulthood and released back into the wild, where it is supposed to be.   You don't expect (or want) those released animals to return to you.

When you "release" a brake, it's so the car can go.  Move forward.  Controlled, yes.  But no longer at a standstill because of what was holding it back.

Both of those thoughts about "release" can be applied to the health journey.

If I "release" my extra poundage into the wild blue yonder, it need to be with the expectation that they will not return to me.  I am purposefully behaving in a way that will send them away.  I am not searching for them.

I am also "releasing" my body from the extra weight.  I move better, feel better, act better.  I am no longer at a standstill because of the extra weight I carry around.

"Losing" weight is a diet, a burden.   It's work.

"Releasing" weight is freedom.  Will it require an effort?  Oh, yes!  But so does backpacking, hiking on a mountain, riding a bike...those are all "freedom" words to me.

From now on, I am not "losing weight"...I am "releasing" it.