Photographer Gregg Segal travelled the world to document children and the food they eat in a week. Partly inspired by the increasing problems of childhood obesity, he tracked traditional regional diets as yet unaffected by globalisation, and ironically, found that the healthiest diets were often eaten by the least well off. (Photo by Gregg Segal/The Guardian)

A vendor smokes behind a display of dog meat at a dog meat market on the day of a local dog meat festival in Yulin, Guangxi Autonomous Region, June 22, 2015. (Photo by Kim Kyung-Hoon/Reuters)

A swimmer competes during the UK Cold Water Swimming Championships at Tooting Bec Lido in south London January 24, 2015. (Photo by Luke MacGregor/Reuters)

A half-naked shrine parishioner using a wooden tub pours cold water onto himself during an annual cold-endurance festival at the Kanda Myojin Shinto shrine in Tokyo, Saturday, January 10, 2015. Pouring cold water on their bodies is believed to purify their souls. (Photo by Eugene Hoshiko/AP Photo)

Raising a flag over the Reichstag is a historic World War II photograph taken during the Battle of Berlin on 2 May 1945, by Yevgeny Khaldei.

Renowned amphibian and reptile photographer Matthijs Kuijpers has released his first book, “Cold Instinct”. Kuijpers says the aim of the work is “for the viewer to abandon the fear and negative thoughts that often surround these animals”. What’s left is the bizarre beauty of these creatures in their simplest form – no backgrounds and no distractions. Here: Mossy frog (Theloderma corticale). (Photo by Matthijs Kuijpers/The Guardian)

Cocoa Beach, Florida, USA. 7th October, 2016. Kaleigh Black, 14, left, and Amber Olsen, 12, run for cover as a squall with rain and wind pelt them while they explore the Cocoa Beach Pier on Friday (10/7/16) after hurricane Matthew passed to the east on Florida's east coast.(Photo by Douglas R. Clifford/Tampa Bay Times/ZUMA Wire/Alamy Live News)

A surfer heads out at Coldingham Bay an inlet in the North Sea on February 15, 2012 in Coldingham, Scotland. (Photo by Jeff J. Mitchell/Getty Images)