The combination of high fat and high carbohydrate in the diet is problematic for weight management.

“it's really in the middle that the problem is and which is ironic because that's where the standard American diet is if you just walk into the grocery store and just eat without any filtering you will eat that wrong combination of fat and carbohydrate exactly and if you look anywhere in the world where people are rich enough and industrialized enough to eat whatever they want that's generally what you're going to see at least after a couple decades of you know cultural adaptation you're going to see pretty equal proportions of fat and carbohydrate”