I guess i technically did. Before I got pg with ds2 I was doing the SCD (specific carbohydrate diet) which is pretty darn NT. Pastured meat, eggs, cultured dairy, nuts, seeds, fruits and veggies. No grains, no sugar and no potatoes. I wouldn't have lost just doing NT because of the grains.
I ate a TON of fat, a ton of meat, fish, eggs, nuts and seeds.
I went very heavy on veggies and fruit as well. It worked really well for my body. I had been vegan and made the change for my nursing dd's health. Turned out it was good for my health too!
I still struggle as I don't like to eat meat, can't do dairy anymore (ds2 can't tolerate it) In my heart I am vegan. The weight stays off as long as the grains stay out and my diet is heavy in leafy greens. I don't gain when I don't eat meat. However, the only thing that made me lose that much that fast was the SCD.