PROS: It’s not for the faint-hearted but what you are allowed to eat will leave you feeling full, and when stuck to, Atkins followers can see a big weight loss in a small amount of time.

CONS: Many Atkins dieters have complained of bad breath and constipation as side effects, and it can be hard taking count of every single carbohydrate intake when you bring them back into the plan.

atkins.com