Researchers found a lower risk of pre-diabetes in people who ate 59 grams of whole grains per day. "This is of great importance because pre-diabetes is increasing," said Tina Wirstroem, lead author of the study, which looked at 5,477 Stockholm residents over 10 years. Researchers also found that 1 in 13 participants became pre-diabetic, while 1 in 33 developed diabetes.