Labels such as “low carb,” “net carbs,” and “Atkins friendly” appear with increasing frequency on everything from restaurant menus to bread, ice cream, catsup and snack chips, including some health food store brands. Helping drive demand for these products is a selection of low-carb diet books and cookbooks. If you’ve been spending your hard-earned dollar on these low-carb foods and self-help guides, it’s important to understand what you’re buying and what it could mean for your health.
First, what does a claim of “low carb” really mean? That’s a tough question to answer, as the Food and Drug Administration has not yet provided a definition for low carb, essentially making manufacturers’ current claims illegal (as the FDA prohibits any nutrient claim that it hasn’t defined). Furthermore, a low-carb message on a food package doesn’t necessarily mean the food is lower in calories or is more nutritious. For example, a popular low-carb health bread lists white flour as its first ingredient, and some carb-conscious cookies and nutrition bars come packed with 7–8 grams of fat per serving.
You may also see the number of “net carbs” identified on food packages. Manufacturers typically derive this number by subtracting certain carbohydrates from the total amount—generally fiber, sugar alcohols used for sweetening (such as sorbitol, maltitol and erythritol) and glycerine—which product labels explain have a minimal impact on blood sugar. However, some of these ingredients contribute to the total number of calories per serving, and some sugar alcohols can have a laxative effect if consumed in excess.
If you’re trying to fuel your body for endurance exercise, a low-carb diet could be ill-advised. According to Len Marquart, Ph.D., RD, assistant professor and researcher in the Food Science and Nutrition Department at the University of Minnesota, “You’re going to feel really lethargic if you’re trying to exercise but don’t have any carbohydrate stores for high-intensity physical activity, making it more difficult to burn off excess calories.”
Regardless of your physical activity level, carbohydrates (in the form of glucose) are your body’s main energy source, fueling the most basic of activities, including breathing, thinking and digestion. If your carb intake is too low, your body will have to convert protein to glucose—a process your body does not perform easily and that leaves unwanted byproducts the liver and kidneys are forced to filter out of your system. Water is also lost from your body when its carbohydrate stores (in the form of molecules called glycogen) are decreased, as carbs are packed with water in storage.
If you begin a low-carb diet, you may mistakenly translate this water loss to dieting success. However, these water-related pounds will likely return when your body works to replenish its carbohydrate stores. The long-term effectiveness of a low-carb diet is unknown, as the longest clinical study to date lasted only a year. A dieter may also find it difficult to stick with a low-carb diet. Research shows drop-out rates as high as 39 percent on low-carb weight loss plans.
For those who do manage to stick to a low-carb diet, scientists and nutritionists are concerned about the potential long-term health effects. Nature packs carbohydrate-rich, plant-based foods with vital nutrients that are important for disease prevention. “Within a whole food such as a fruit, there is a synergistic effect of vitamins, minerals, fiber and phytochemicals [plant-based nutrients including antioxidants]. It’s not that there is one magic bullet, but rather, there are a variety of different compounds that help reduce risk for certain chronic diseases, including heart disease and cancer. The synergy of all these different nutrients in the body is absolutely essential, and that’s why a balanced diet composed of a variety of foods is so important,” says Marquart.
Balancing your diet with calories from protein, carbohydrate and a bit of good fat can go a long way toward helping you manage your blood sugar, hunger and ability to concentrate. Making wise carbohydrate choices is an essential part of this balance and includes cutting down on refined carbohydrates, like sugar and white flour. When choosing carb-containing foods, strive for at least three whole-grain servings per day rather than refined grains, and beware that “wheat flour” is not the same as “whole wheat flour,” with the latter meaning whole grain and the other indicating nutritionally inferior refined grain. Aim for at least three servings of vegetables and two servings of fruit per day, emphasizing minimally processed, whole food forms. And don’t forget to include nutrition-packed legumes (beans).
If you do choose to include some of the new low-carb foods in your diet, take a careful look at what you’re really getting for your money. As Marquart relates, a standard loaf of whole grain bread will cost you around $2.50 a loaf, but some of the new low-carb breads are at least double that price and some are lower in whole grain ingredients. Why not enjoy the carbs that nature has already perfected in whole, natural foods?
Tips for eating a natural moderate low-carb diet
- Reduce the intake of highly refined carbohydrates (cookies, white bread, white pasta and white rice).
- Select 3 servings of whole grains (cereal, bread, rice) and at least 5 servings of nonstarchy fruits (berries) and vegetables (leafy greens, broccoli) per day.
- Cut back on sugar and hydrogenated vegetable fats.
- Substitute chicken, legumes, nuts and fish for red meat.