Upton Sinclair was keenly interested in health and nutrition. He experimented with various diets, and with fasting. He writes extensively about fasting in The Fasting Cure, which became bestseller. Sinclair believed that periodic fasting was important for health, saying, "I had taken several fasts of ten or twelve days' duration, with the result of a complete making over of my health". Sinclair favoured a raw food diet of predominantly vegetables and nuts. For long periods of time, he was a complete vegetarian, but he also experimented with eating meat. His attitude to these matters is fully explained in the book's final chapter, "The Use of Meat".