Low-Carb Diet: Will It Work for You?
Carbs, essential nutrients in food, are the body's favored energy source, providing fuel for everyday activities and ensuring everything from your muscles to brain function properly.
Not all carbs are nutritious. "Good" ones are minimally processed and packed with vitamins and minerals. Sources include whole-grain pasta and bread, veggies, and fruit. "Bad" ones, from foods like white bread and sugary sweets, pack lots of calories and don't have much nutritional value.
What's a low-carb diet?
Low-carb diets supply fewer carbs than most experts would generally advise. While the government recommends that adults get about half of their calories from carbs, low-carb diet plans may provide as few as 10 percent of daily calories from carbs.
What are some examples of low-carb diets?
Popular ones include Atkins, Dukan, Eco-Atkins, Medifast, the Paleo Diet, and the South Beach Diet. See below for more information and links about these diets.
What can I eat on a low-carb diet?
Think protein and fat. Chicken, meat, fish, shellfish, and eggs are all low-carb foods. High-carb foods—sweets, pasta, potatoes, and bread—are discouraged on this type of diet, as are many fruits (too much sugar) and starchy vegetables, like potatoes.
How do low-carb diets work?
If the body is an engine, then carbs are the gas that makes it go. Limiting that fuel by shunning high-carb foods makes the body instead turn to burning stored fat. Weight loss is said to ensue.
Will I lose weight on a low-carb diet?
It's hard to say. Low-carb diets are known for yielding fast weight loss. Shedding up to 15 pounds in two weeks on Atkins, for example, isn't out of the ordinary. However, much of what's initially lost on low-carb diets is water, not fat, because these diets have what's known as a diuretic effect. That's true of many other diets, too, and is a major reason researchers don't judge diets based on a few weeks of results.
Studies also haven't proven it's the curbing of carbs—rather than the restricting of calories—that produces weight loss. A study published in 2009 in the New England Journal of Medicine showed that over a two-year period participants lost roughly the same amount of weight—6 to 7½ pounds—whether they were on a low-carb (35 percent carbs) or higher-carb (65 percent carbs) diet. In 2003, researchers who analyzed about 100 low-carb studies concluded in the Journal of the American Medical Association that weight loss on those diets was associated mostly with cutting overall calories and not specifically with cutting carbs.
It's also not clear if low-carb diets work better than other diets in the long run. A 2010 study published in the Annals of Internal Medicine found that at that two-year mark, low-fat and low-carb dieters had lost the same amount—about 7 percent of their initial weight.
Low-carb diets can also be notoriously difficult to stick to, given their often lengthy lists of off-limits foods. Even clinical trial participants who know they're being studied have trouble adhering to low-carb diet plans. None of the low-carb diets evaluated by U.S. News ranked in the top five weight-loss diets, though two—Atkins and Eco-Atkins—came close.
Are low-carb diets risky?
They carry some risks, according to experts. Restricting carbs makes it difficult to get the recommended amounts of whole grains, fruits, and vegetables, so it's possible you'll come up short on fiber, potassium, calcium, and other key nutrients. Low-carb diets that are high in saturated fat may also hurt your heart, increasing cholesterol and raising the risk of heart disease and stroke. None of the low-carb diets evaluated by U.S. News ranked among the top five diets for heart healthy. Finally, side effects of low-carb diets include weakness, nausea, dizziness, constipation, irritability—and bad breath.
Popular Low-Carb Diets
U.S. News has profiled the following low-carb diet plans: