Objective: To evaluate the body composition, resting energy expenditure (REE), and energy intake of adolescents and adults with Williams syndrome (WS) compared with matched healthy control subjects.
Methods: Body composition was determined by total body electrical conductivity and anthropometric measurements in six subjects with WS from the WS Clinic at Children's Hospital of Philadelphia and six healthy control subjects matched for age, height, and pubertal stage. REE was measured by open-circuit indirect calorimetry. Dietary intake was assessed by 3-day dietary records.
Results: Subjects with WS had similar anthropometric measurements to the control group except for a significantly lower percent body fat (17.1%+/-5.2% vs. 25.0%+/-6.7%). Dietary intake (measured in kilocalories per day) was similar between the two groups. REE was statistically higher by 155 kcal/day in the WS group after controlling for age, gender, and body composition. In addition, the WS group had a significantly higher percent predicted REE according to the World Health Organization equation, which adjusts for age, gender, and body weight.
Conclusion: Adolescents and adults with WS have a similar dietary intake but a lower body fat than healthy control subjects. A higher REE may contribute to the thin body habitus and reduced total body fat stores of people with WS.