1. Departament de Bioquímica i Biologia Molecular, Institut de Biomedicina de la Universitat de Barcelona (IBUB) and CIBER Fisiopatologia de la Obesidad y Nutrición (CIBEROBN), 08028 Barcelona, Spain
2. Laboratory of Metabolism and Obesity, Unit of Diabetes and Metabolism, Institut de Recerca Vall d'Hebron, 08035 Barcelona, Spain
3. Department of Nutritional Science and Toxicology, University of California, Berkeley, Berkeley, CA 94720, U.S.A.