How do eating disorders affect thyroid function?

ABSTRACT

Abnormal thyroid function in patients with eating disorders can result from malnutrition. A low serum triiodothyronine (T3) level is commonly noted in starvation states and is caused by reduced peripheral conversion of thyroxine (T4) to T3. Diminished T4 concentrations are also observed. Adequate nutrition normalizes this type of aberrant laboratory profile. Thyroid function tests that give results below the normal range are best repeated initially for verification of results and again after adequate nutrition is reestablished. If no primary endocrinopathy is present, spontaneous correction of these laboratory values can be expected with conventional dietary habits.