This may help its from the Pink site.
I am a Muslim; how can I continue with the ‘Sole Source’ programme during Ramadan?
Ramadan occurs in the ninth month of the Muslim year. During daylight hours, rigid fasting is observed which means that Cambridge Diet and water will need to be consumed before sunrise and after sundown. During the time available, intake should be spread out as evenly as possible and might necessitate rising a bit earlier. It is not advisable to take more than one diet at a time as the increased carbohydrate intake may take the customer out of ketosis, making it even more difficult for them to stay motivated and stick with the programme.