OK, maybe metabolism can be a mitigating factor. Some people (fidgety people?) might have a really high metabolism. Perhaps you can have a few outliers who burn

OK, maybe metabolism can be a mitigating factor. Some people (fidgety people?) might have a really high metabolism. Perhaps you can have a few outliers who burn excess calories like some kind of rodent; but I doubt there's outliers with with a python-like metabolism who can spend weeks living off the deer they just swallowed. There's a base-line for what a warm-blooded human burns at rest (or at a desk), and not everyone with that slow calorie burn rate is severely overweight.