[tomhoward]

Obligatory reminder that correlation is not causation.

Of course, avoiding obesity is advisable for everyone where possible, for all kinds of reasons.

But there are cases where a complex physiological problems (particularly autoimmune issues) can contribute to obesity and cancer risk.

Such cases are quite possibly more frequent than is generally understood, given how many people try and fail to lose weight through diet and exercise.

[satanspastaroll]

I doubt any disease will grant you more energy than what you've eaten nor conditions that substantially improve the bodies efficiency. It's important to remember that exercise alone won't burn off that many calories. It's diet that is primarily responsible for that

[tomhoward]

It’s an argument that is as old as the hills and relies on the assumption that the body functions like a simple furnace, which of course is false.

Metabolic rates vary significantly, and rates of absorption of nutrients and consumption of energy vary a lot as a result of factors such as inflammation and endocrine function.

Calories in/calories out may still ultimately be true when you boil it down far enough, but the factors influencing and intervening in those processes are vastly complex and strongly affected by diseases and dysfunctions that are very common.

Thyroid disorder (which can include cancer or a precursor condition) is probably the most common/known, but just one of many.