The FAST Start phase is the first three days, followed by 4 days of Trimsition (which takes you through to 7 days all up), then we recommend going on to the Body Trimming phase for the final 11 weeks. The initial phases of the program start with meal replacement shakes and through the successive phases we gradually reduce the number of these per day while introducing you to whole foods and portion sizes.
Really, the sooner you can get onto introducing whole foods the better, the FAST Shakes are not designed to be a long term thing, but they are a handy and convenient option which you could potentially use from time to time in place of a meal. If you feel you need a little longer to adjust then you could stay in the Trimsition phase perhaps for a couple of days longer, but long term we encourage you get stuck into those whole food options! Just make sure you stick to the recommendations for serving sizes.
BT Nutritionist 🙂