Reality T.V. shows on weight loss are sending the wrong message about health, says Natalie Ingraham, of the University of California and author of an ongoing study of “The Biggest Loser.” Ingraham presented her work at the 2011 American Public Health Association conference where she spoke on a panel about “The Politics of Obesity.”

At first blush, “The Biggest Loser” seems to demonstrate that anyone can lose weight. ...