Among other claims, Netflix’s “Fit for TV: The Reality of the Biggest Loser” alleges Michaels plied contestants with caffeine pills even though they were supposedly banned, restricted competitors’ calorie intakes to dangerously low levels, and denied medical care and medicine to some.

Carla Triplett made The Biggest Loser history when she appeared on the show’s seventh season in 2009 at 379 pounds — the heaviest for a contestant at the time.

One of the shocking stories has included a contestant revealing that the physical training she underwent on her first day filming led to her waking up in the hospital and realizing “I knew I died that...