Just because it's 20, 40, however many years past whatever knowledge was handed down, it doesn't mean that biology and metabolics don't apply.
Most people today sit on their ass looking at screens all day. Most people today eat processed carb-loaded food when they should be easting lean meats and vegetables. You don't have a medical disorder, you have a sedentary disorder.
Prader-Willi syndrome people and others with a true medical condition have a legitimate reason for being overweight.
As for the rest of you, stop eating and start moving. And yes, I've been there, 50 lbs. overweight after babies. Now I do pilates and am at the right weight. And I am basically at heart a lazy person who likes to eat and sit around and read books all day but decided I don't want to be a sick feeble person when I'm old so I'm doing what I can now.
PILATES is the bomb!!!!