TV highlights: Al Jazeera America launches

News channel Al Jazeera America launches Tuesday, taking over for Current TV. On "Extreme Weight Loss" (ABC at 8 p.m.), trainer Chris helps Ashley, a mother who feels tremendous guilt over the death of her baby daughter and thinks that her obesity caused her early labor. Ashley's husband, Jason, also gets on board with the weight-loss program, and Chris sets the couple up with workouts alongside members of the former U.S. Olympic softball team.