BackgroundThe aim of this study was to find an association between moderate, vigorous and total physical activity (PA); diet quality; and bone mineral density (BMD) among patients suffering from inflammatory bowel disease (IBD).MethodsWe enrolled 54 IBD patients, including those with Crohn's disease (CD) and ulcerative colitis (UC), and 24 healthy adults. All subjects completed the Questionnaire of Eating Behaviour based on which prohealthy and nonhealthy diet indexes were calculated, and the questionnaire included questions from the International Physical Activity Questionnaire. Prohealthy and nonhealthy diet indexes were divided into low‐, medium‐ and high scores. BMD and T‐ and Z‐scores of the lumbar spine (L1–L4) and femoral neck (FN) were assessed using dual‐energy X‐ray absorptiometry method.ResultsBMD, T‐ and Z‐scores of the FN and the Z‐score of L1–L4 were significantly lower among patients with CD and UC than healthy controls. We did not find any differences in the time of PA among CD, UC and control groups (CG). The prohealthy diet index was higher among healthy subjects than the CD and UC groups. The nonhealthy diet index was lower among UC patients compared with the CG or CD patients. Prohealthy diet index positively correlated with BMD and T‐ and Z‐scores of L1–L4 and FN in IBD. The prohealthy diet index correlated negatively with C‐reactive protein and positively with body mass index. The prohealthy diet index correlated only with total PA in the CD group.ConclusionA well‐balanced diet and proper PA may decrease the risk of osteoporosis in IBD, so education of patients referring to nutrition and PA is needed.