Scientists have theorized for decades about how the human brain evolved and grew dramatically in size. Now, new research points to one common ingredient that may have played a crucial role in the brain’s evolution over time: sugar. These new findings challenge an older scientific model that emphasizes meat as a primary driving force behind human evolution. Throughout human evolution, brain size increased from roughly 300 grams in early hominins to approximately 1,500 grams in modern humans. Sugar was also not the human brain’s only source of fuel, nor were carbohydrates the sole dietary factor influencing human evolution.