The international bestseller by food expert Rens Kroes. Bülent did the complete design and art concept of the healthy food book and worked with photographer Anne Timmer on making this a food book with photography that stood out. The first Powerfood book has also been released in the United Kingdom, United States, Canada and Australia due to its enormous success in The Netherlands. This was the beginning of a successful partnership for Bülent with Rens Kroes, that has lasted for four books. And more is on the way.