Here’s a little excerpt from Eric David’s website talking about his experience with the Brentwood Diet by Dr. Mizrahi:

Low-carb, high-protein diets are “ketogenic,” which means it puts your body into ketosis. Ketosis is when your body basically switches from burning carbs to burning fat for fuel. The first week or so of getting into ketosis are a little hard: you have low-grade headaches, some dizziness, and grumpiness. It’s your brain rebelling at switching over to the new fuel source and it desperately does not want to switch. After all, carb energy is all it has known for years. But best to bite the bullet and muddle through the “induction flu,” as it’s called, as quickly as possible. “People ask me why I don’t start the diet gradually,” Dr. Mizrahi told me. “You don’t go to boot camp and start exercises gradually. You dive in.” But it isn’t that bad and is over soon. And after a week or so, you wake up to realize you have more energy, need less sleep, don’t get hungry and are shedding pounds like crazy!  You can use ketosis strips if you want to check if you’re in the fat-burning state or not, but you can skip that also and just trust you’ll get there if you stick to the diet.

Exercise is not required on the Brentwood Diet, although of course it helps burn calories, live longer and raise your fitness level. The pounds come off without it, and it’s interesting to see, contrary to most people’s conceptions, how working out for hours in the gym doesn’t do as much as simply cutting back on bad foods, week over week. It’s the old 80/20 rule.

To see more on his experience, check out his site which he tries to update every Friday.