Aug. 21, 2014 at 9:31 AM ET
Carbs are not the enemy. Since NBA star LeBron James posted an Instagram picture of his slimmer physique recently the sports world and beyond have been buzzing about his low-carb diet.
A report in the Wall Street Journal claims the 6' 8" James became noticeably leaner after following Heat guard Ray Allen's "Paleo" diet. Paleo (short for Paleolithic) diet lovers shun carbs with more gusto than Atkins diet fans of the early 2000s. Paleo proponents eat meat, fish, shellfish, poultry, eggs, vegetables, roots, fruits and berries — a diet believed to be similar to foods hunted, fished, or gathered by our ancestors. If you eat Paleo, you can’t have grains, dairy, or legumes (beans or peas). Sugar and salt are also no-no’s.
There's little science supporting the weight loss or health benefits of a Paleo diet. While it does provide fiber, potassium, and vitamin B12, the diet falls short on calcium and vitamin D. And if there’s one nutrition Americans don’t need more of on our plates, it’s protein. It's recommended that 10 to 35 percent of your daily calories come from protein. Paleo encourages amounts of protein and fat beyond current federal recommendations.
Even before the skinny LeBron photos emerged, our carb romance has been on the rocks. While overloading on pasta, bread and potatoes can contribute to weight gain and diet-related diseases, such as heart disease and type 2 diabetes, going to the opposite extreme by slashing carbohydrate and increasing protein intake (especially fatty meats) isn’t the answer, especially if long-term weight loss or optimal performance at work or in sports are your goals.
Here are three things people often get wrong about carbs:
1. To lose weight, I need to cut carbohydrates.
Science says: It’s about calories. Eating foods low in carbohydrates won't guarantee weight loss unless you're cutting the amount of calories you consume daily. A recent review of 19 studies published in PLoS One found that overweight or obese subjects lost similar amounts of weight after following diets that were low carbohydrate (less than 45 percent of total calories) or balanced (45 to 65 percent of total calories).
Previous studies also suggest that adults with higher carbohydrate intakes actually weigh less than those with lower carbohydrate intakes. One study even found that those who consumed 47 to 64 percent of their total calories from carbohydrates —in line with current recommendations — had the lowest risk of being overweight or obese.
Choose small portions of healthful carbohydrate-rich foods (made with little added fat or sugar) like high-fiber whole grains (oats, whole wheat bread, brown rice or air-popped popcorn), fruits and vegetables, legumes and potatoes.
Limit refined grains — pasta, white rice, and white bread — to no more than two or three one-ounce equivalents daily. A one ounce-equivalent is half-cup pasta or white rice.
2. I don't need carbohydrates.
Science says: Carbohydrates are broken down into glucose, the important fuel needed by your brain, red blood cells, your entire central nervous system and even your muscles. When you skimp on carbohydrates, your body uses stored body fat to generate glucose. That may sound great, but eventually going too low in carbohydrate for too long causes your body to use protein from food and your muscles to create glucose.
And if you use fat and protein to create glucose, they can’t be used to perform their many functions. According to the National Academy of Science’s Recommended Dietary Allowance (RDA), minimum daily glucose needs can be met by consuming 130 grams (520 calories) of carbohydrates. The Institute of Medicine recommends 45 to 65 percent of total daily calorie needs from carbohydrate.
For someone who consumes 2,000 calories, that’s 900 to 1,300 calories daily.
Besides providing energy, carbohydrates supply your body with a steady stream of serotonin. This brain chemical, a type of neurotransmitter, helps regulate mood, appetite and sleep. When you eat carbohydrate-rich foods, your blood sugar level rises. This leads to the release of the hormone insulin. The insulin paves the way for the amino acid tryptophan to pass into the brain where it ultimately creates serotonin. Too little carbohydrate— and too little serotonin —can contribute to fatigue, irritability and other negative effects.
And if you run marathons or do other endurance activities, carbo-loading prior to events and supplementing during events can help meet nutrient needs and enhance performance. But it’s best to turn to a registered dietitian well versed in sports nutrition for advice about amounts and types of carbohydrates to ingest to meet your individual needs.
3. Carbohydrate-rich foods aren’t healthy.
Science says: Whole grains like oats, brown rice and even popcorn are rich sources of fiber that fill you up and support a healthy gastrointestinal system. Whole grains also supply the body with antioxidants to protect cells from damaging chemicals that contribute to aging and disease.
That’s right, carbs help slow aging.
While refined grains are not typically as nutritious as whole, they’re not as bad as you think. A 2012 review in Nutrition Reviews of 135 studies found no associations between moderate intake of refined grains and cardiovascular disease, diabetes, weight gain or even death.
Nutritionist Elisa Zied, R.D., is founder and president of Zied Health Communications, New York, and author of "Younger Next Week."