I get what you're saying, but the way you're presenting it doesn't make a lot of sense. If you eat only when you're hungry you will most likely maintain weight, unless you make a conscious effort to eat less than what you require. Which, in itself, is "dieting", though I realize you are using it in the sense of ridiculous/fad nutritional programs.
Also, sociodynamics are fun and all, but what humans have been like prior to the modern availability of food doesn't really relate to what they are now. Say you eat a
diet consisting of peanut M & M's, but only eat when you're hungry... Pretty sure you're not gonna achieve/maintain good health and
body composition doing it.
As per my little disclaimer above, I'm not really disagreeing with you, I just think you're oversimplifying in the wrong direction. I feel it would be better to say, for example, "It is enough to eat quality foods and be (more) physically active." Or, "It's enough to watch what you eat and be (more) physically active."
P.S. I have lost almost 40 lbs more than you, and am working on the remaining 40, and I also have a degree in biological science, but I don't believe either is a guarantee that I know what I'm talking about, or that what has worked for me and some others will work for everyone.
