Thyroid conditions are among the conditions I was referring to when I said certain medical conditions... none of what I said applies to you if you have a thyroid condition. In that case your metabolism might indeed differ from the norm.
I explained about my hyperthyroidism, the Sythroid meds I take, AND my
well-regulated metabolism for the last 23 years...for 2 reasons: (1) My medical condition then
was an example
in support of some of what you'd said about causes of changing metabolism. (2) However, my metabolism was "normal"
for 23 years...before
I quit smoking. There was NO medical condition
nor other cause during the next 1.5 years, for my progressive weight gain and drastic lessening of my energy level. That's why I said the following in the next paragraph then:
"There are definitely other things than starvation or a medical condition, that can cause one's metabolism to noticeably vary from their "norm". My endochronologist and my own labwork can verify 1 of them."
That "1 of them" above...
was my quitting smoking! My endo. told me that some of the thousands of "the other chemicals" in cigarettes, can/do have an effect on metabolism. Since I was no longer smoking...I
wasn't getting them any more. He said initially, that hopefully, my body would just become accustomed to not having them, and my energy level would return to normal and my weight gain would stop. But it didn't, for 1.5 years. It was then that we tried the additional med. my body didn't like, and finally raising my nic level a total of just 1mg over the next 6 months. That did the trick!
That said, most people have pretty normal metabolisms, and that is not a matter of opinion.
You never made
that statement, but if you had...I'd definitely have agreed
with it. You said, "Unless you have been starved for a while, or have certain medical conditions,
your metabolism will not vary much from the norm." That is just
not true, per my own experience after quitting smoking.
Much that should not be, is blamed on metabolism. Gaining weight when you quit smoking is an egregious example.
I agree with the 1st statement above, to a degree. However, having an underactive or overactive thyroid
are 2 frequently long-undiagnosed conditions, especially since TSH testing
isn't a part of routine bloodwork most people have done. I will also agree that many who quit smoking, (
and aren't getting nic in some other way)...
probably do gain weight because they're getting no appetite suppressant any more = more snacking, or possibly eating more since their sense of taste is returning.
But...I will never agree with, "
People don’t gain weight when they quit smoking because their metabolism changes," because
I know for a fact, that's sometimes
it is the reason.
When you give up a powerful appetite suppressant you should not be surprised if you gain a bit of weight, and you hardly need to invoke changes in metabolism to explain that.
But, when that "powerful appetite suppressant" is
not given up, (because the ex-smoker
is still getting nicotine another way)...the possible cause for the weight gain, shouldn't be assumed to be
only 1 thing (food related)...for everyone without a current, diagnosed, medical condition.
I've provided info. that I'm aware of relating to the OP's post, based on my own personal experience and what I know to be true because of that, and on info. gained from my endo. But everyone has the right to think whatever they want to about anything, and to post their thoughts here, within reason of course, or the mods "will cometh". So I'll just stop now.