A new study claims to debunk the basis for the popular Paleolithic Diet, which stresses, low-carbohydrate, high-protein eating.

The diet is centered on the assumption the humans evolved while eating diets heavy on meat, fruits, and vegetables, but with few starches, grains, and other foods high in carbohydrates.

A study published in the journal Quarterly Review of Biology found that it is likely humans did eat plenty of carbs as they evolved, most likely in the form of starchy tubers.

The scientists argued that carbs would have been necessary for the human brain to develop as it did, tripling in size and complexity during evolution. Meat and fruit would have been inadequate to fuel this level of brain growth, they said.

The human brain uses up to 25 percent of the body's energy budget, and up to 60 percent of blood glucose.

While synthesis of glucose from other sources besides starchy foods is possible, the researchers said, the high-glucose demands of the developing brain were unlikely to have been met on a low-carb diet.