The problem is the entire processed food system. I'm glad you mentioned that stress contributes - lack of sleep, lack of time for personal pursuits, resulting in the higher percentage of people in low wage jobs who are obese/overweight. I don't know who wrote first, or why some people are considered experts and I am not. I recently completed an investor business plan for two NYC physician-experts. They promote the Green Mediterranean diet to heal the microbiome and assist in obesity treatment as well as medications, supplements, counseling and lifestyle coaching and support. https://medium.com/p/f36c417c6e1c