The same crops that have fed a rapidly expanding global population over the last 50 years may pose problems for the global food chain as pests and limited diets spread, according to a new study.

Crops such as wheat, corn, potato, and soybean, as well as meat and dairy products make up a bulk of the world’s diet today. Meanwhile, once regionally important crops such as millet, sorghum and yams are losing ground, explained Colin Khoury, a visiting research scientist at the International Center for Tropical Agriculture in Cali, Colombia, and the study’s lead author.

“It is not all bad, but there are some very significant implications on both the agricultural side and on the nutritional side,” he told NBC News.