Why can't the Dalai Lama be a vegetarian? In this answer to 'Are all Buddhists vegetarian?' the poster says


  [the Dalai Lama] has a medical condition that disallows
  him to be a strict vegetarian.


I've heard this before and never questioned it. But thinking about it - what kind of medical condition would preclude the Dalai Lama from being a vegetarian. Suddenly I feel very skeptical that there is any such condition. Is that unfair?
According to this article, Is the Dalai Lama a vegetarian? on a web site named &quot;Reasonable Vegan&quot;,

When the Dalai Lama fled Tibet in 1959 he took residence in India, the birthplace of the Buddha and a region with a rich tradition of vegetarianism. Here he adopted a vegetarian diet which he has described as being rich in milk and cream[2]. After 20 months of vegetarianism he succumbed to a Hepatitis B infection [3] and was encouraged by his doctors to resume consumption of meat to aid his recovery.

The web site's opinion is that meat-eating isn't necessary (which contradicts his doctors' advice):

It’s quite possible that doctors advised this change in diet, but it is unnecessary advice since usually acute hepatitis B infection in adults is overcome by the patients own immune system. If the Dalai Lama’s infection was severe (which from his description it sounds like it was, jaundice causing yellowing of the skin is seen in patients suffering severe hepatitis B) he may have required antiviral treatment. Some studies have been published assessing the potential effects of nutritional supplements or adjustments on Hepatitis B patients none of which suggest consuming meat as either a remedy or therapy[5]. Eating healthily is advised for all patients especially those with liver inflammation so perhaps the advice to change his diet was appropriate ‘lay off the cream’ but returning to regular consumption of meat is unlikely to have had any effect on his recovery.
Since recovering from his illness the Dalai Lama has remained convinced that he is unable to be vegetarian, let alone vegan. It is hard to understand how he can maintain this belief when brief research into hepatitis B or the nutritional adequacy of a well balanced vegetarian or vegan diet reveals etc.

Also FYI, here's a different article which may give some background information or insight into the prescriptions of Tibetan doctors: Medical advice from the Dalai Lama's doctor.