Complex sentence: His voluminous body (due to a metabolic disorder) strikingly contrasted with his normally discrete way of acting, his low voice was often loaded with undertones of kindness, pity or scorn.
Split into simpler sentences: His voluminous body (due to a metabolic disorder) contrasted strikingly with his normally discrete way of acting. His low voice was often loaded with undertones of kindness, pity or scorn.