I would agree that exercise has been oversold (or maybe misleadingly sold is a better description) by gyms, personal trainers, shoe companies etc. However, my feeling is that your book might have gone too far the other way and undersold the value of exercise in weight loss/maintenance. Your experience is that you feel like exercising nowadays because you eat right, but my experience reverses the cause and effect, ie I believe that I feel like eating right because I exercise. I am not sure if you read the transcript of the interview, but there seems to be some physiological explanation for my experience with exercise helping to reduce cortisol levels with the effect of controlling appetite as well as negating some of the harmful effects of fructose.
I guess that I feel this way because I can't think of any other logical reason that I am not overweight. I am in my forties and have three children and have always eaten quite of lot of conventionally "healthy" food as well as regular treats (particularly ice-cream). Given that this included breakfast cereals, juice, muffins, fruit, yoghurt, my diet would have been high in fructose (and I totally accept that fructose is highly addictive) and yet I am a slim. I don't think it is good genes. Several members of my immediate family are overweight and we were all similar builds as children. The only lifestyle difference that I can think of is exercise.
Do you have any alternative theories? I can assure you that it's not willpower!!
Katy
PS I also agree that exercise should not be a chore. The idea of running on a treadmill in a gym makes me think of rats in cages. Being outside in the early morning doing something you enjoy like walking, swimming or running is a joy.