I gained a lot of weight on a medically prescribed carbohydrate diet- over 100lbs- and yes i know i was stupid listening to them. Ive lost a lot of weight since i started primal ,see below. I keep my carbs between 30 and 80 but i watch the calories too. Virtually all my carbs come from vegetables with a few from lower sugar fruits. I don't eat processed carbs at all. Keeping a check on the pair of culprits has worked really well for me.
If you eat enough of anything you will gain weight and if your intake is less than your energy expenditure you will lose. There are many ways to lose weight. The difference with this way of eating seems to be satiety before vast calories are consumed whereas with a carb based diet its very easy to consume a lot of calories quickly but never get full so get hungry quicker