Not necessarily sd, but bulking in general, carbs are needed to gain mass
If your leaning out and on a low/no carb diet, you can high on to a fair amount of muscle, but you will more likely lose muscle than gain
To bulk, carbs provide the energy and blood sugar, while proteins are absorbed into the proteinacious tissues in your body(muscles)
With no carbs, your body breaks down proteins to make blood sugar (glucogenesis) in your liver. and if you do not eat enough protein, it breaks down the proteinacious tissues in your body
Bottom line, any anabolic works best with carbs, and carbs work best 1st thing in the AM and PWO, but carbs are only needed to power you through your workouts, so don;t over due it
(I just basically summarized an article by dave palumbo)
While I am on, I eat 35g oatmeal with chocolate WPI mixed in, and after workouts i through in some waxy maize (35g)
On a 3 1/2 week mdrol run, I put on about 16 of lbm, and kept about 12 after pct