The calories burnt is nearly unrelated to the lifestyle.

Chronic inflammation is one of the major contributors to many serious diseases.

The immune system over commits with a lot of available calories. The body produces also cortisol.

Working out restores a physical balance in the body.

Obesity is in contrast caused by overeating. "Humans are mad for calories".

So working out does not really help to lose fat, but it gives the body more balance, make human more resilient and prevent the diseases.