A Yemeni soldier, pictured through a vehicle's windscreen, which was damaged by a bullet, gestures out of the window, in Marib, Yemen October 15, 2015. Marib is a city that is heavily armed even by the standards of Yemen, where the ready availability of weapons helped start civil war and is now preventing anyone coming out on top. Yemenis often say there are three guns for every person, a boast that has become an urgent concern in a country where the United Nations says the humanitarian situation is "critical". (Photo by Angus McDowall/Reuters)

People wearing bear furs perform during a festival of New Year ritual dances attended by hundreds in Comanesti, northern Romania, Wednesday, December 30 2015. In pre-Christian rural traditions, dancers wearing colored costumes or animal furs, toured from house to house in villages singing and dancing to ward off evil, in the present the tradition has moved to Romania's cities too, where dancers travel to perform the ritual for money. (Photo by Vadim Ghirda/AP Photo)

A member of the pro-government “red shirt” movement attacks a Buddhist monk outside the National Anti-Corruption Commission office in Nonthaburi province, on the outskirts of Bangkok March 24, 2014. Members of the movement attacked the monk after he shouted complaints to the group blocking a road near the National Anti-Corruption Commission. (Photo by Chaiwat Subprasom/Reuters)

A stunning photographic collection featuring portraits of people from 30 countries and the food they eat in one day. In this fascinating study of people and their diets, 80 profiles are organized by the total number of calories each person puts away in a day. Featuring a Japanese sumo wrestler, a Massai herdswoman, world-renowned Spanish chef Ferran Adria, an American competitive eater, and more, these compulsively readable personal stories also include demographic particulars, including age, activity level, height, and weight. Essays from Harvard primatologist Richard Wrangham, journalist Michael Pollan, and others discuss the implications of our modern diets for our health and for the planet. This compelling blend of photography and investigative reportage expands our understanding of the complex relationships among individuals, culture, and food.

Mario Huettenhofer, chief of the German company 3D Fab, presents his own face as 3d print during the international fairs FabCon 3.D and Rapid.Tech in Erfurt, Germany, Thursday, May 15, 2014. 130 exhibitors from all over the world present the entire world of 3D printing. The trade fairs are accompanied by specialist programs featuring 80 scientists, practitioners and trend analysts from ten countries, who will explain the latest findings, trends and applications for additive processes in industry and for 3D printing in the private sector to newcomers, experts and consumers alike. (Photo by Jens Meyer/AP Photo)

“Winter Climbing from inside Ben Nevis”. The view from inside the mountain, as a winter climber passes through the cave on Minus Three gully. Photo location: Ben Nevis, Fort William, Scotland. (Photo and caption by Daniel Wildey/National Geographic Photo Contest)

U.S. Corporal Stanley Suski, left, and Miss Tamako, a Geisha girl, whirl a bit of Jitterbug, in a bar, in Tokyo, Japan, on October 1, 1945. (Photo by AP Photo)

A picture made available on 20 October 2015 shows a foreign tourist posing for a souvenir photograph with a figure of a tiger head at a private zoo on Phuket Island, Thailand, 17 October 2015. Each day hundreds of tourists, including young children, visit the private tiger zoo where visitors are allowed to touch and pose for photographs with unchained tigers inside their enclosures. (Photo by Rungroj Yongrit/EPA)