ABSTRACT.Objective. In children with idiopathic short stature (ISS), studies investigating body mass index (BMI) or parameters of satiety regulation are scarce, and studies analyzing eating behavior are lacking.Methods. We recruited 214 children (123 index cases and 91 siblings) with ISS from 123 families. Affected children had to have a body height <5th percentile, or, in the case of siblings, the body height of 1 child had to be <5th percentile and the other <15th percentile. Medical histories were recorded by using structured and standardized interviews. Eating behavior was assessed by using the Child Eating Behavior Questionnaire. Percent energy intake as fat was assessed by using the Leeds Food Frequency Questionnaire. Endocrine markers of body weight regulation (leptin, ghrelin) were determined in serum.Results. Compared with population norms, BMI was significantly lower (mean: ؊0.33 standard deviation score). Furthermore, there was decreased food responsiveness (mean Child Eating Behavior Questionnaire score: 1.9; population mean: 2.4), reduced enjoyment of food (3.2 vs 3.9), emotional undereating (2.6 vs 3.0), lower desire to drink (2.0 vs 2.8), and increased fussiness over food (3.2 vs 2.9). When the sample was subdivided into the 2 groups of "good" and "poor" eaters according to the mothers' assessment of the current eating behavior, reduction in BMI as well as the behavioral characteristics already delineated in the total sample were found to be even more consistent in the subgroup of poor eaters. In the total sample of our children, as well as in both subgroups, serum leptin (adjusted for gender, BMI, and Tanner stage) was found to be moderately raised but did not differ between poor and good eaters. Total serum ghrelin was not different between poor and good eaters. ABBREVIATIONS. CDGP, constitutional delay of growth and puberty; FSS, familial short stature; ISS, idiopathic short stature; IGF-I, insulin-like growth factor I; IGFBP-3, insulin-like growth factor-binding protein 3; CEBQ, Child Eating Behavior Questionnaire; SDS, standard deviation score; LFFQ, Leeds Food Frequency Questionnaire. S hort stature is the most common cause for referrals to pediatric endocrinologists. Many of these patients have no identifiable medical abnormality and are classified with diagnoses such as constitutional delay of growth and puberty (CDGP), familial short stature (FSS), or idiopathic short stature (ISS). For most of these patients, the etiology of their short stature is currently unknown, although it is believed that genetic variations are the underlying cause. 1,2 In young children, CDGP is typically defined by short stature (height below the third ageand gender-specific percentile), bone-age retardation of at least 1 year, and a positive family history of delayed growth and pubertal development; however, in a strict sense, the diagnosis cannot be made before the time of puberty, when a delay in sexual maturation becomes evident. Patients with FSS reveal a family history of short stature, whereas osseous deve...