The new definition of healthy foods aims to turn that around by excluding foods with excess sodium, saturated fat and added sugars even if they also contain valuable nutrients like protein and whole grains.

Japanese sake, an alcoholic beverage made from grains, was also added to the list this year.

In the new study, the researchers carefully inserted 1,200 pieces of fishing line -- one at a time -- through a thin, vertical slice of material with four pores that represent spherical grains of gravel.

Similar transitions occur in many biological processes, including the development of an embryo: cells are "squishy" biological "grains" that form solid tissues and sometimes flow to form different organs.

Arid nations in the Middle East and North Africa are currently the world’s most import dependent, with 11 of the 16 nations importing most of their staple grains.