Ever since the rise of the low-carbohydrate diets in the early 2000s, people have been confused about how many carbohydrates to eat. Despite popular belief, carbohydrates are not inherently fattening. Your body needs a considerable amount of carbohydrates to support health and provide energy to stay active.
Carbohydrates are one of the three macronutrients that provide calories. They are the main source of energy for your muscles and brain, so it’s important that a bulk of your daily calories come from carbohydrates. Carbohydrates are found in foods like fruits, vegetables, grains, dairy and legumes. Your carbohydrate choices should come from nutrient-rich selections within these groups. For example, choosing whole-wheat bread rather than white bread provides carbohydrates for energy but also gives your body fiber, vitamins and minerals.
The recommended daily allowance for carbohydrate is at least 130 grams per day. This baseline level will help to properly fuel your brain and muscles. You may need to take in more carbohydrates though, as the Institute of Medicine recommends that 45 to 65 percent of your daily calories come from this macronutrient. If you’re eating a 2,000-calorie diet, this would equal 900 to 1,300 calories from carbohydrates -- or 225 to 325 grams per day.
If you are an endurance athlete -- for example, if you run marathons or participate in triathlons -- you need to aim for the higher end of the recommendations for carbohydrates to fuel training and racing. Carbohydrates are stored as glycogen in the muscles and provide energy for the training associated with these athletic activities. Athletes should aim to get 55 to 65 percent of their calories from carbohydrates, or about 3 to 5 grams per pound of body weight. A 150-pound endurance athlete would require between 450 and 750 grams of carbohydrates per day. The more hours of training and the higher the intensity, the closer the athlete would need to be toward the top of this range. In addition, athletes need to consume carbohydrates during endurance events lasting longer than an hour in order to keep supplying energy for the muscles.
You may have considered experimenting with a low-carbohydrate diet to lose weight. Low carbohydrate diets may help you lose weight, but the amount of weight lost is typically not different from higher-carbohydrate diets that reduce calorie intake. In addition, low-carbohydrate diets may cause side effects like headaches, weakness, fatigue and constipation, according to the Mayo Clinic. Because carbohydrates are contained in many nutrient-rich foods like fruits and whole grains, cutting out too many carbohydrates may result in an inadequate intake of certain nutrients such as fiber.
- PBS News Hour: Low Carb Craze
- Institute of Medicine: Dietary Reference Intakes: Macronutrients
- Nancy Clark’s Sports Nutrition Guidebook; Nancy Clark, M.S., R.D.
- International Olympic Committee: Consensus Statement on Sports Nutrition 2010
- Mayo Clinic: Low Carb Diet: Can It Help You Lose Weight?
Chrissy Carroll is a registered dietitian and certified personal trainer with the American College of Sports Medicine. She holds a Bachelor of Science in nutrition from Boston University and a Master of Public Health from the University of Massachusetts, Amherst.