Not as bad as some people say:
A Swedish researcher put 18 volunteers on the same diet that filmmaker Morgan Spurlock went on while filming "Super Size Me."
one volunteer gained 15 percent body weight after following the
high-choleric diet for a month, several others experienced only minimal
weight gain. [He] was thus forced to conclude that "some people are
just more susceptible to obesity than others."
Also: The 12 men and six women were banned from exercising.
While all gained weight, none reported mood swings or liver damage like Spurlock did in the movie.