I am a former personal trainer. Do NOT do this!! 1)eating fat doesn't make you fat. Excess calories do. Fat has 9 cals per gram, protein and carbs have 4. If you eat 500g of protein a day that equals 2000cals. If you eat 222g fat that equals about 2000cals.Your body doesn't care which way you do it, 2000cals equal 2000 cals. Also, why walk for 3 hours? Most people claim walking burns a lot of calories because you can do it for a long time. I can sleep or twiddle my thumbs for a long time but I don't burn a lot of calories! Look at the bodies of marathon runners versus sprinters. Which do you want to look like? If you like the marathon people fine, do loooooooong workouts. If you want the sprinter body do hard, fast workouts. BTW-2g fat plus 170g carbs= about20+680=700 calories a day. Just so you know, the Nazis discovered that the human body can stay alive on about 900 cals a day. Go look at Holocaust victim's pictures. YOU WILL BE EATING LESS THAN THEM ON THIS DIET!! yes this is true... you can go on that stupid diet if you want, but it wont do u any good. eat low amount of calories and burn them off!