It works wonderfully if someone's eating the foods that their body evolved the tools to work with. But intuitive eating tends to crash very quickly when high calorie additives, sugary drinks or artificial flavoring comes into play. And that's not even counting the effect that lifelong medication places on people. So many psych meds, in particular, mess with hunger responses. I absolutely think intuitive eating can work for people who aren't on any medications and who only eat unprocessed foods. But that's such a minority of the overall population that it's hardly worth considering.