The introduction EDIT: "of" medication side effects as a refutation to calorie balance models does not work. What the medications appear to do is alter the way the person responds to the environment, meaning it causes them to eat more or burn fewer calories.
Jono: I've been trying to understand your claim for awhile now, and I think you're interpreting the claim that obesity is caused by overeating as identical to the claim that obesity is caused by
choosing to overeat. This is not the same claim.
For the most part, overeating is probably a lack of choosing in general. Most people are not really paying attention to the calorie consumption. Arguably, this is a choice too, but it's different than any deliberate choice to overeat.
This is the core of most research into weight management, and the reason Dr. Wansink titled his book "mindless eating" - mostly we're not choosing to overeat, undereat... we're not choosing to reduce our eating triggers... we're just following habits and responding to environmental cues, many of which are intended to make us consume more calories.
As an example, my cat was losing weight dramatically due to hyperthyroidism, so we've put him on a topical methimazole. This is a pretty clear cut example of a drug side effect impacting metabolism and ultimately calorie balance.
He gained weight until he achieved the target weight, and we have recently reduced his kibble and treat calories to maintain that healthy weight. I have to be the food gatekeeper because he has a brain the size of a walnut and no capacity to understand the concept.
So yes: our weight management has a physiological element. But we're not dumb cats. We can understand what's happening. With this in mind... one model I suggest could work for some people is to imagine their eating impulses as the behavior of the Id-like "animal" part of us, and for our Ego to use its agency to take responsibility for trying to mitigate the Id's influence on what we eat.
ETA: and an important component of mitigating overeating is accepting that we're not as in control as we think, so have to alter the environment. We respond to environmental cues somewhat unconsciously no matter how strongwilled we are. We're not making as many choices as we want.
In principle, skeptics are fine with this, but there's a second level that many skeptics haven't crossed yet, and things can go from bad to worse. Specifically, many skeptics think that being aware of manipulation makes us immune to it. It doesn't, and we have to go a level up and eliminate the manipulation whenever possible.