Again.......see above. It's all in WHAT you eat.
The one part of the email that I really agree with is where it says not to stuff yourself. I do believe it's fairly key to stop eating as soon as you're not hungry anymore. And don't eat again until you are hungry, which shouldn't be for some hours unless you ate just carbs, then hunger comes faster.
I've also noticed that when you are really busy and concentrating on and consumed by the job at hand that you won't eat until you truly get hungry. And then the desire to stuff oneself seems absent.