Final answer:
It is true that first degree relatives to a proband with an eating disorder are at a higher risk than second degree relatives, due to genetic links and environmental influences that both play significant roles in eating disorders.
Step-by-step explanation:
It is true that first degree relatives to a proband with an eating disorder are more at risk for developing an eating disorder compared to second degree relatives. The predisposition to eating disorders within families can be attributed to both genetic and environmental factors. Biological evidence suggests that an imbalance in neurotransmitters, such as serotonin and dopamine, as well as the hormones leptin and ghrelin may lead to an increased risk due to their role in regulating appetite and eating behavior.
Biological Factors
Genes play a significant role in the development of eating disorders, which is evident from the substantially increased risk observed in individuals with a close biological relative who has an eating disorder. Leptin, mainly produced by fat cells, normally inhibits appetite, and ghrelin, produced in the stomach and small intestine, stimulates the appetite.
Environmental Factors
In addition to biological factors, environmental influences such as childhood abuse, parental control over eating, cultural ideals, and social isolation also contribute to the risk of developing an eating disorder.