[invasuant]

so did a bit of paperwork avoidance and googled hcg and leptin, found this little tidbit that supports mgsondance's thinking about the breaks:
Dr Simeons created his diet based on 1950s knowledge about human physiology. The discovery of the master fat hormone, leptin, in 1994 substantiates his thinking. Leptin and HCG both work by sending signals throug brain receptors in the hypothalamus. Lab reasearch with experimental animals is just now starting to show how these two hormones interact to regulate fat metabolism.

Teh carb connection in this scenario involves insulin, which also has a close interaction with leptin. If either one of these hormones gets out of balance, the other one willl too. Consuming excess carbs will make you fat more quickly than will any other kind of food. These hormones work together to make it so. This iwhy eating carbs during the three week post HCG phase ruins your newly acquired metabolism

Dr Dennis Clark