think people are eating more than they think/say and moving less than they think/say
I think this too. And it is very different to saying x gains more weight than y on the same food and drink intake and the exact same energy output and the exact same weight and frame.
because ultimately if you burn off more energy than you consume you then burn fat or muscle to make up the defecit. Thus making your body lighter. No one fuels a defecit with fresh air. It is humanly impossible.
however some people may have very low energy outputs, be very sedentary even though they don’t realise it, maybe walk to the car, walk to the loo, walk to the kitchen, sit down most of the day, that sort of level of sedentary, which coupled with a slow metabolism may mean they don’t need much to fuel themselves and they over estimate how much they need, and under estimate how much they consume, it is very very easy to do.
I see so many people swear blind they eat in a deficit, but can’t lose weight, on line, but they are unable to explain how they fuel the deficit if it isn’t burning fat or muscle. Where the additional energy comes from if it is not something consumed, or burning your own fat or muscle. It is simply humanly impossible to fuel a deficit with fresh air, which is the only thing left.
which means fundamentally they burn off a lot less than they think, consume more than they think, or a little of both.