What does it mean to lose an inch from your waist? To answer that question you'd have to know how many inches your waist is already. The larger your waist the more fat you'll need to lose to lose an inch (unfair, right?).
|Calculations to figure out inch/weight relation|
For instance, going from a 33" to 32" (assuming 5" height between your underbust and natural waist) requires a loss of 0.856 lb's of fat whereas going from a 30" to 29" waist requires 0.779lb's of fat. That might seem like an insignificant difference but if you're starting at a waist size of 40" and want to go to a 30" waist then you'd have to lose 9lbs. That doesn't sounds like a lot but considering that you can't choose where your body loses fat AND we're a lot bigger than 5" tall, well, it adds up.
Another concern that I hear often is that weight lifting will cause you to bulk up. Let's look at how much muscle it would take to gain an inch (density of 1.06 g/cm^3 vs. 0.9g/cm^3 for fat). If you have mathematica you can check out a worksheet
that I made that allows you to make these calculations. However, it ends up being a gain of 0.959lbs of muscle would cause you to gain an inch around your waist. That doesn't sound like much until you consider that AT MOST (eating an extremely clean diet and lifting HEAVY) a woman can gain only 0.5-1lbs of muscle/month with a maximum of about 20-25lbs total for her lifetime (assume a steriod-free woman) see here. You also have to consider if you're lifting weight it's most likely focused more on your arms/shoulders/back/legs and the vast majority is going to go there (probably most specifically legs for women). The point is, it would be really, really hard to gain 1lb of muscle on your waist and make it an inch wider. Add to that, how many women lift weights on their core? Especially enough that would cause a serious gain of muscle mass there?
I have to admit, I don't have much to say here. Yep, weight loss can cause loose skin. Yep, stretch marks never really go away (but they do fade). It sucks, I know. That being said, I like my body a hell of a lot more now than I did when I was well over 200lbs. I feel better and I have more self-confidence so for me it's a no-brainer. Shapewear can do wonders and any partner that really can't deal with your battle scars probably isn't worth your time in the long run either. I even wear a bikini (ok it's a high-waisted one but nevertheless it's a bikini and some of my stretch marks peek out the top) and nobody has gone blind yet from seeing me in it.