Malnutrition is a common sequel among patients affected by Crohn's disease (CD). The pathogenic mechanisms include poor dietary intake, increased resting energy expenditure (REE), nutrient malabsorption and loss. So far, few studies have been carried out in CD adult patients, assessing the effect of disease activity on both REE and body composition. Vaisman et al (2006) studied sixteen CD patients in remission (> 3 mo) and showed no effect of REE on lower BMI, although in the presence of similar energy intake in according with previous studies (Al-Jaouni et al., 2000; Schneeweiss et al., 1999). While, Gong et al., 2015 found that patients with active disease had an increase in REE compared to patients in remission as already shown by Rigaud et al., 1993; Kushner and Schoeller, 1991. Overall, the effect of disease activity on REE is still uncertain and requires further investigation.

The aim of this study is to investigate the effect disease activity on resting energy expenditure (REE), body composition, inflammatory markers, food intake and quality of life in subjects affected by Crohn's Disease (CD)