In obesity, these cells may show preference to differentiate to adipocytes rather than osteoblasts, decreasing bone formation.8 In addition, obesity increases the amount of proinflammatory markers such as osteoprotegerin ligand, which promotes osteoclast differentiation and activation, increasing bone resorption.9 In the digestive tract, increased fat intake may interfere with calcium absorption in the gut because of binding with fatty acids, thus decreasing the availability of calcium for bone formation.10 The gene discussed is TNFSF11; the disease is obesity due to melanocortin 4 receptor deficiency.