Carbohydrate had a pretty good reputation until the late 1990s. Then the low-carb diet craze hit. Suddenly carbs were considered to be as bad as fat had once been. Like all diet fads, the low-carb craze fizzled. It was followed by a rash of diets based on the glycemic index, which measures the effect of carbohydrate-containing foods on blood sugar levels. Those diets seem to have run their course as well.
One of the benefits of all the attention that the low-carb diet craze and the glycemic index diet phase brought to carbohydrates is that it inspired a lot of scientific research. As a result, we now know a lot more about how carbohydrates affect the body than we did a decade ago. This recent accumulation of knowledge has allowed nutrition experts to dispel some popular myths about carbohydrate.
For example, we now have certain knowledge that carbs are not the primary cause of unwanted weight gain. The prevalence of overweight and obesity has increased drastically in the past 30 years. This trend cannot be accounted for by changes in levels of carbohydrate consumption. Rather, the true cause of America’s weight problem seems to be that we are simply eating more of everything. According to government statistics, the average woman eats more than 20 percent more calories today than in 1971, while men eat roughly 7 percent more calories.
A recent scientific review found that men and women who consume the highest levels of carbohydrate as a percentage of total calories are less likely to be overweight than those who consume fewer carbs. While low-carb diets have been shown to be effective for weight loss, they are no more effective than low-fat diets in the long term.
Following are five basic guidelines for carbohydrate consumption that are based on current scientific knowledge:
Get most of your carbs from fruits and vegetables. Carbohydrate is the primary macronutrient in fruits and vegetables. In other words, these foods contain a lot more carbohydrate than protein or fat. Fruits and vegetables are the best sources of carbohydrate for two reasons. First, their carbohydrate content is absorbed slowly—that is, they have a low glycemic index—which is good because carbs are less likely to be converted to body fat when they are absorbed slowly. Second, fruits and vegetables have a lot fewer calories and a lot more vitamins, minerals, and antioxidants than other carbohydrate sources, such as grains.
Eat whole grains instead of processed grains whenever possible. There’s nothing wrong with including a moderate amount of grains (wheat, rice, etc.) in your diet, but these grains should be whole grains such as brown rice rather than refined grains such as white flour. Refined grains have been stripped of their fiber, a type of indigestible carbohydrate that slows the absorption of other carbohydrates, and most of their other nutrients.
Vary your carb intake with your activity level. Unlike protein and fat, which are used structurally in the body in addition to providing energy, carbs are used only to provide immediate energy for mental and physical activity. Any carbs consumed in excess of the amount needed to meet immediate physical and mental energy needs are converted to body fat. So the amount of carbohydrate you consume needs to be determined by your activity level.
If you don’t exercise and have an office job, you should not consume more than three or four grams of carbohydrate per pound of body weight. If you perform physical work or exercise moderately, aim for five or six grams per pound. If you are highly active, seven or eight grams of carbohydrate per pound of body weight will be needed to keep your body functioning optimally.
Strictly limit your sugar intake. The sugars that are added to foods such as cookies and candy bars and to beverages such as lattes and energy drinks should be avoided as much as possible. They add a lot of calories to these products and thereby promote weight gain. Consuming large amounts of sugar over many years may also increase the risk of type 2 diabetes independently of weight gain. If there truly is any “bad carb,” sugar is it.
Pay attention to how carbs affect you physically and mentally. Different people react to carbohydrates differently. Some people absorb carbs in foods much faster than others do and are thus more susceptible to “blood sugar crashes” an hour or two after eating a high-carbohydrate meal. Pay attention to how you feel and function after consuming large amounts of carbs and adjust your diet accordingly. If you feel lethargic and perform poorly after eating carbs, you should reduce the amount of carbohydrate in your diet.
Eat protein with your carbs. When protein is consumed with carbohydrate, the carbs are absorbed more slowly and the meal is more filling. It’s a good idea to consume some form of lean protein whenever you consume carbohydrate-rich foods. Permalean protein bars and shakes are the world’s best sources of lean protein and a very convenient way to add protein to your snacks and meals.
