There's a 650 calorie/pint figure cited on many, many sites, but I can't find the original source for it. Some sites claim it comes from the Mayo Clinic, other

There's a 650 calorie/pint figure cited on many, many sites, but I can't find the original source for it. Some sites claim it comes from the Mayo Clinic, others list the source as the University of California San Diego, and so on