We're all stuck in the 'obesity' calories in/out mindwarp-some are just trying to escape it. It's like being brought up in a faith then becoming ex-muslim or catholic.
The same issue inevitably appears in the issue of post-pregnancy self image. Some women- they may or may not be a small percentage but they definitely exist and are a distinct group-have bodies which instinctively re-assumes its pre-pregnancy shape on its own, give or take.
This is homeostasis, the body's self regulatory instincts, restoring it's own
equilibrium. The same thing that makes their bodies snap back on their
own, is what makes most people regain weight after restriction induced
weight loss [RIWL].
From the outside their bodies resume an unaffected look. Either they looked like a normal post-partum and yet regained a pre-partum size/look, or straight after giving birth. Some women only look pregnant from the front. I'll never forget a fleeting glance I got of a woman from the bus. I first saw her back, slender curved in waist. Then she turned around and she had a stand out fully pregnant belly.
Human variety is intriguing.
Pregnancy marks every woman from the inside and out- if only minimally for some. Pathologists can tell if you've been pregnant post-mortem. The expectation is pregnancy should substantially and visibly affect your body, and should have to make huge effort to recover prior size and shape if at all.
Typically, many formerly slim women have allowed themselves to become so self righteous about what could for them quite pronounced changes-when you consider the fetid air of body hierarchy. They can be careless, displaying hostility toward those whose bodies respond less dramatically. The thin/slim ones obviously, though some fat women's bodies also barely change or not much.
Celebrities, rather like models get paid for their appearance. They employ staff to coach them through strenuous work outs, have nutritionists on call and often personal chefs to prepare those recommendations.
It's like insurance for their earnings. They're less likely to take a chance waiting to see how their bodies respond, if they can help it. They need to restore their pre-pregnancy image quickly, often its as much about image as anything. They do not wish to appear to weakened by anything, they wish to have a sheen of being unaffected by anything associated with ordinariness. It can ruin their expensively cultivated aura.
Letting go of that must be something like one of us letting go of a lifetimes investment in (internalized) fat hating of ourselves.
Post-partum is especially a time to be kind and gentle with yourself and other women in the same situation. No look is more authentic than others, that kind of thing is unnecessary, the envy and resentment is all too obvious. It's not however the fault of the thin rebounder their body is as responsible for that as yours is for the way it is.
I suspect it's entirely possible that they are how bodies are supposed to respond and those getting pompous are more anomalous- though they may seem more prevalent. Trying to almost cast quick rebound as bad form is silly.
Often its a question of time anyway. Many recover more slowly, some much more. It's probably another example of forgotten/lost knowledge of how to help the body's natural restoration process along.