Final answer:
Carbohydrates should make up about 55% of daily caloric intake according to the American Heart Association, with a focus on complex carbohydrates. Athletes may need to increase their intake to support energy demands during intense training or competition.
Step-by-step explanation:
The percentage of macronutrient intake that should be carbohydrates varies by dietary recommendations, but there is a general consensus that a significant portion of caloric intake should come from carbohydrates, especially for those with higher energy demands like athletes. The American Heart Association recommends obtaining about 55% of your daily calories from carbohydrates. It's important to note that these should predominantly be complex carbohydrates, which are accompanied by essential nutrients like vitamins and minerals, as opposed to simple sugars commonly found in junk food.
For athletes, carbohydrate needs can increase to about 3-10 grams per kilogram of body weight per day, depending on the intensity of training or competition. As a rule of thumb, it is suggested that 50-70% of total caloric intake come from carbohydrates for maintaining optimal energy levels. When considering the caloric content of macronutrients, both proteins and carbohydrates provide approximately 4 Calories per gram, whereas fats provide about 9 Calories per gram.