Excessive thinness/malabsorption can be a big problem for some people.
Dr. Morse's advises that a diet of raw fruits and vegetables with the addition of astringent and tissue-specific herbs is still necessary to address the root causes of the problem.
Depending on the individual case, it's okay to speed up and slow down, when appropriate. In other words, if you need to take a temporary break from, say, a high or all-fruit diet rich in high water content fruits in order to increase intake of dense fruits, green juices, olives, avocado, coconuts, raw salads, and the occasional cooked vegetable meal – in an attempt to “build up” – then don’t hesitate to do so. When you feel comfortable enough, jump back into the more aggressive levels of detoxification.
Please download and read the following document:
PDF: Thinness