Dietary carbohydrates play an important role in mood regulation, mental health, and cognitive performance, which is driving rapid development in studies on the diet-brain interaction. The review will focus on the intricate relationship between brain function and carbohydrate intake, emphasizing how different types of carbohydrates impact mental health and cognitive outcomes. Simple carbohydrate intake (often known as "sugars") is consistently linked to a decline in overall cognition, while complex carbohydrate intake is linked to both short- and long-term memory improvement and successful brain aging. Dietary macronutrients affect the brain and cognition through a variety of pathways, including glucose and insulin metabolism, neurotransmitter effects, and cerebral oxidation and inflammation. Carbohydrate supplements appear to enhance cognitive function in people who engage in prolonged, high-intensity physical activity with high energy requirements.