Eating Disorders May Run in Families
Pattern Seen in Studies of Anorexia, Binge Eating
Anorexia's Warning Sign
The Swedish twins had also been studied in the early 1970s, when most of them were teens. That data let the researchers check, in hindsight, for anorexia's warning signs.
The researchers checked BMI (body mass index), physical activity levels, gastrointestinal problems, and neuroticism. Only neuroticism predicted anorexia, the study shows.
Neuroticism is "the tendency to be anxious or depressed, and also a tendency to be emotionally reactive," Bulik says.
"What that means is things that might be like water off a duck's back for someone who is low on neuroticism, [for] someone who's high on neuroticism they're like emotional Velcro," she explains. "So things just stick to them and impact them more, emotionally, than for other people for whom they can just brush it off and move on."
"It's really that tendency towards being anxious and depressed that seems to be the core that predicts the later onset of anorexia nervosa," Bulik says.
Taking It Seriously
"If you have eating disorders that run in your family and especially if you have a child who's starting to show some of these anxious and depressive traits, you should be alert for any signs of eating-disordered behaviors," Bulik says.
"Take them seriously, and if they do become concerning, head right toward early detection and early intervention," she says. "Because we do better when we can detect and intervene earlier [with] anorexia nervosa."
She lists these possible warning signs:
- Falling off the growth curve (losing weight needlessly)
- No longer eating with the family
- Saying things like "I hate my body" or "I feel fat"
- Being very anxious or depressed
- Going on a diet needlessly
If a child is "normal weight and they come home and say they're going on a diet, take that seriously, just as if your child would come home and say, 'I'm going to smoke my first cigarette.' It should be just as much of a red flag," Bulik says.
Bulik also worked on the binge-eating study, along with other experts.
The study included 300 overweight or obese Americans -- half of whom had binge-eating disorder -- and their families. In binge-eating disorder, people consume unusually large amounts of food in a short time (usually less than two hours).
The researchers interviewed the family members. They found that 20% of those with an immediate relative with binge-eating disorder had ever had the same problem, compared with 9% of those whose relative didn't have binge-eating disorder.
The study doesn't show why binge-eating tended to run in families. Genes and environment could both be factors, but it's not clear how much either contributed, write the researchers, who were led by James Hudson, MD, of the psychiatry departments at Harvard Medical School and McLean Hospital in Belmont, Mass.