Changes in body composition, substrate oxidation, and resting metabolic rate in adult celiac disease patients after a 1-y gluten-free diet treatment

Background: The incidence of celiac disease has been on the rise in both Eu rope and the United States. Celiac disease patients are at high risk of und ernutrition because of nutrient malabsorption. Objective: The aim of the present study was to evaluate changes in body com position and energy metabolism in a group of patients with celiac disease b efore and after consumption of a gluten-free diet (GFD). Design: Body composition (by anthropometry and isotopic dilution), resting metabolic rate (RMR), and substrate oxidation rates (by indirect calorimetr y) were assessed in 39 adult celiac disease patients (16 men and 23 women) with a mean (+/-SD) age of 29.9 +/- 7.6 y, weight of 58.3 +/- 6.6 kg, and p ercentage body fat of 20.1 +/- 6.7%. and in 63 (29 men and 34 women) age- a nd height matched control subjects (age: 33.2 +/- 8.1 y; weight: 66.8 +/- 6 .6 kg; and percentage body fat: 25.4 +/- 3.7%). Celiac disease patients wer e studied twice, at diagnosis and 1 y after treatment with a GFD. Results: Before treatment, celiac disease patients had a lower body weight (P < 0.05) and a higher carbohydrate oxidation rate (P < 0.01) than did con trol subjects. Carbohydrate oxidation rates correlated positively with feca l lipid loss in untreated celiac disease patients (r = 0.80, P < 0.0001). A fter the CFD, percentage body fat was higher in celiac disease patients tha n in control subjects (P < 0.01), and lipid intakes tended to be higher tha n before treatment. Conclusions: This longitudinal study showed that the GFD treatment signific antly increased body fat stores. Untreated patients preferentially utilized carbohydrates as a fuel substrate, probably as a consequence of both lipid malabsorption and a high carbohydrate intake, and lipid utilization increa sed with the restoration of the intestinal mucosa.