That being said I do fully understand and appreciate that many factors go into a person's size namely DNA, bad metabolism, depression, medications that cause you to gain weight, etc.
I notice when people talk of this matter they overlook the obvious .... eating to much...
I have a few friends who want to lose weight .. I've lost 50 pounds .. when They ask me .. and I say it's about eating less.... portion control ..
they say no no I just need to join a gym ... or what ever ..
that being said other than a few medical conditions ... over eating is the cause of being overweight... period...
by the way I lost 50 after quiting smoking by eating 6 small meal 3 to 4 hours apart ... always a little hungry never too full..
I'm type 2 diabetic .. which forced me into this diet