As an alternative, there is no one single cause of the obesity epidemic. People are made of confounding factors, and the world is very complicated. The world does not owe you simple explanations.

Two books have helped me understand the obesity epidemic:

Burn by Pontzer - https://www.amazon.com/Burn/dp/0241388422

Podcast about above: https://www.youtube.com/watch?v=8CSNS45RJL0

Hungry Brain by Guyenet - https://www.amazon.com/Hungry-Brain-Outsmarting-Instincts-Ov...

Podcast about above: https://www.youtube.com/watch?v=AlWriMdYuKk