Sure it will. I have lost about 20 pounds over the course of 2 months with the help of intermitent fasting. I've done three so far. One for 5 days (8lbs lost), another for 4 days (about 5 lbs lost) and I am doing one now (day three with 4 lbs lost). Four months is a loooong time. 30lbs should be a snap as long as you stay to a diet of raw veggies, lean proteins, and NO SUGAR!!!! Oh, and of course, lots of water. And I would suggest water fasting. I find it a lot easier than juice fasting. Hope that helps!