If you can follow it, it can work. Studies are all over the place as to whether mostly cutting carbs is actually better for you than sticking with them. Paleo supporters will talk about how much better it is to stick to fats and proteins, and carbs are the enemy, but there are just as many claiming the opposite. Either way, the lifestyle is really hard to maintain, imo. I love carbs, so I couldn't keep it up for more than a month. It takes longer than that to notice any real differences. If you stick to it, you'll burn fat for energy (ketosis), but if you're a typical American you'll likely die before sticking to it.