That sounds like pseudo-science in itself. while I am all for meat, I have cut back on my own intake of it, eating more fruits and vegetables. But as Smalls mentioned, the BIGGEST, by far, change in the human diet is SUGAR. EVERYTHING has sugar. go to your local grocery store and you will see that "natural" yogurt has 12g sugar if not 14. Why does "natural" yogurt have that much sugar per serving? Flavored yogurt (strawberry, blueberry, etc.) can have as little as 16g and as much as 20,. Usually the cheaper something is the more sugar they put in it, so brand does matter. Fruit juice is the same way. These days one cannot escapte sugare and people don't take the effort in cutting down because after having their apple juice and some yogurt, they'll have ice cream and a chocolate bar... sugar, sugar, sugar.
The first step in losing weight is a LIFESTYLE change, not a diet, this isn't something you are doing for six months, it is for the rest of your life. cut back on the junk as much as you can. THEN it is excersice and not a whole lot. Look at Zare's post, he walks a decent distant and plays sports... that's all you need. You don't have to go to the gym. It helps, but you don't have to.