Want to know why processed food like chips is so addictive? It combines fat and carbohydrates with a layer of crunchiness. Yale University researchers have found that this triggers more activity in our brain’s reward centre than if the fat and carbs are eaten separately, possibly because it’s a rare combination in nature and we aren’t evolved to deal with it. When crunchiness is added, the treat becomes even more addictive because we associate crunchiness with freshness. You’ll be shocked by how many processed snacks fit the formula.