So what happens when you get so hungry you can't think at work, and you find your ability to ride hard disappears? Does this not happen to you? Cos it happened to me.
Er.... everything I would like to say about food and exercise (which I'm aware I have spelled differently about 3 times..) would be much better articulated in a conversation, rather than by text.
I find our relationship with food to be a fascinating subject, historically, generationally, socially, biologically, in evolutionary terms and from a medical/health point of view.
To answer the above, yes it does happen on occasion, but IN MY OPINION AND EXPERIENCE, this is a relatively temporary effect, and easy to deal with; just have a Mars bar, or a pie, or your dinner. My misgivings about the iDave thing is as above; I think, for me, it's too close to being too important. I just eat less, and even skip meals when I'm not hungry. In terms of 'training' or just riding which is more accurate these days, I know I can ride for 3 hours without much to eat or drink, and I know that I will feel wasted for about 4 hours afterwards if I choose not to eat straightaway, but it's only temporary, and not worth changing my feeding for.
When I started racing, and was training hard, I didn't use any gels or sports drinks; water and the odd kit kat when I was dying was about it.
In later years I used sports food and drink a lot on my bike, and recovery stuff afterwards, but put weight on as a consequence.
My view is that we can regulate our weight by food intake and exercise because we are animals, but the social, historical blah blah of food in our society messes that up.
Eat less move more works for me, and I appreciate that you don't find it so.