Maybe. See my post 285. But there will always be a market for diet plans appealing to what people want to believe.
Our capacity to deceive ourselves knows no bounds. For instance, put the word "salad" in the name of a dish, and people will convince themselves that it's good for them. Go to a salad bar... iceburg lettuce with diced ham, shredded cheese, bacon bits, and a half-cup of thousand island dressing... well, sure it's good for me, it's a salad, isn't it?