i think with the cambridge diet they made up the excuse about nutrients when making the shakes hot, but i think the real reason is the aspartame (sweetner) in the cambridge shakes.
i have had alot of bad reactions to aspartame and i found this on a site about it.
"Two isolated amino acids in aspartame are fused together by its third component, deadly methanol. In this structure, methanol bonds the two amino acids together, but when released at a mere 86 degrees Fahrenheit, the methanol becomes a poisonous free radical.Methanol breaks down into formic acid and formaldehyde, embalming fluid. Methanol is a dangerous neurotoxin, a known carcinogen, causes retinal damage in the eye, interferes with DNA replication, and causes birth defects"
so this is why i think they say not to heat the cambridge shakes, the exante shakes however do not contain this sweetner so there is no reason why you can't heat them, i mean you would heat the food that would contain the nutrients that the shakes are trying to replace so why should it be any different heating the shake?
just my 2p