Amy Dickinson is a general advice columnist.
DEAR AMY: I'm a 16-year-old girl. I'm worried about my dad. I think he may have an eating disorder (most likely anorexia). He eats very little, often just an apple for dinner, logs his calories and often does high-intensity workouts. He's worried about the possibility of gaining weight and sometimes tries to restrict our pets' food, too -- though they're healthy. My mom has a healthy enough relationship with food, though she has felt pressure over the years as my dad engages in disordered eating. My younger sister and I are slowly realizing just how much this is harmful, and sometimes I've caught myself with an unhealthy preoccupation with my weight. What do I do? I want to talk to my dad about this somehow, but I have no idea how to do this. He's very stubborn and focused, so getting him to change wouldn't be the easiest thing to do. If my behavior with food becomes a problem, I'll tell my doctor and try to get help.
DEAR WORRIED: It is not your job to police your father. Realistically, aside from registering your concern to him and your mother, there is little you can practically do to get him to change.
Eating disorders are linked to addictive behaviors -- the person with the disorder becomes addicted to feeling a certain way and obsessively clings to the feeling of control that comes from limiting food.
One concern is how this disordered eating is creeping into the rest of your household. If your father is truly limiting the pets' food, then the pets should be placed in a safer environment. Animals cannot always fend for themselves.
You should speak with both of your parents about this, not offering solutions but simply being honest about your concern. Start with this: "Dad, I'm worried about you."