The claim is usually that A) people have an inflexible appetite and will be increasingly driven to eat while at a caloric deficit, B) at some point this is almost involuntary and that point differs between people (e.g. consider not eating for three weeks; some people can do it on a hunger strike or a fast, but it really sucks), and C) some people have a slower metabolism which puts them under greater pressure to eat.
I don't disagree that calorie restriction is effective. I just think that you're dropping appetite from the equation when GLP-1 agonists have proven that reducing appetite is effective too.
I don't disagree that calorie restriction is effective. I just think that you're dropping appetite from the equation when GLP-1 agonists have proven that reducing appetite is effective too.