How much do you know about calories and carbs?
By Kathleen Zelman, MPH, RD, LD
WebMD Weight Loss Clinic - Expert Column
Many people think that all they need to do is cut carbohydrates from their diet, and they will lose weight. Eating plans that cut out carbohydrates can only get their nutrients from protein, fats, and alcohol -- there are no other sources of calories. So if you cut out carbohydrates and load up on butter, bacon, and hamburger, how can you possibly lose weight?
Well, the answer is simple, and it's nothing new. No matter what you've heard about net carbs and impact carbs, weight loss boils down one thing: Calories in versus calories out.
How much do you know about carbohydrates and calories? Take this simple quiz to find out.
1. True or false: Carbohydrates are all the same, whether they come from potato chips or vegetables.
False. Technically, all carbohydrates have the same number of calories per gram. But from a nutritional standpoint, they differ greatly. A soft drink, for example, gives your body little more than simple carbohydrate calories. Compare that with carbohydrate-rich fruits, vegetables, and whole-grain products, which are loaded with fiber and antioxidants that keep you feeling good and also ward off diseases. So your best nutrition bet is to cut refined carbohydrates from foods such as sugar and white bread, and replace them with high-fiber alternatives such as whole-wheat pasta, breads, and cereals.
2. True or false: You get more calories from foods high in carbohydrates than those made up mostly of protein or fat.
False. Fat has more calories than either carbohydrates or protein.
Much like a ruler measures length, calories measure units of energy. Nearly all foods and beverages (except water) contain calories. The number of calories in food and drinks is an estimation of the energy units they contain. Calories (or, more technically, kilocalories) are used throughout the body, to fuel physical activity and keep your bodily processes running smoothly. Your heart, brain, lungs, muscles, and all your vital organs need these energy units to function (vitamins and minerals also play a key role in all of your body's metabolic functions).
Calories can only come from carbohydrates, protein, fats, and alcohol. One gram of carbohydrate equals 4 calories, as does a gram of protein. A gram of fat, meanwhile, equals 9 calories, and the same amount of alcohol equals 7 calories. So, gram for gram, fat has twice as many calories as carbohydrates or protein.
3. True or false: Most of us eat too many carbohydrates.
True. Americans eat too many calories, period, and many of them come from sweets, sugars, and fats. It's not just about too many carbohydrates but too much of everything, including protein, fat, and alcohol. Your WebMD Weight Loss Clinic eating plan follows the guidelines of the National Academy of Sciences (NAS). The NAS recommends a diet in which 45% to 60% of total calories come from carbohydrates, primarily in the form of low-fat dairy products, fruits, vegetables, and whole grains such as whole-wheat bread and brown rice. The NAS recommends that 10%-35% of calories come from protein, such as seafood, skinless poultry, and lean meat, and 20%-35% come from healthy fats such as vegetable oils, nuts, and seeds.
4. True or false: Weight loss is faster and more effective on a low-carbohydrate diet.
False. Any diet that drastically cuts calories will result in fast weight loss, but research shows that fast weight loss tends to be followed by fast regain. Weight loss results from eating fewer calories and expending more energy with physical activity. The real test of any diet is whether it helps you keep the weight off permanently.
Following a low-carbohydrate diet generally puts you into a state called "ketosis," which means your body has no carbohydrates to burn for energy, so it burns stored fat or whatever else is available. Ketosis tends to reduce hunger, so often you end up eating a very low-calorie diet. Of course, it's calories that count when you are trying to lose weight. And every fad diet, one way or another, manages to cut calories.
There are some undesirable side effects of a low-carbohydrate lifestyle, including constipation, bad breath, headaches, and potential vitamin and mineral deficiencies. In the long run, a diet high in fat -- especially saturated fat -- may also increase your risk of heart disease and some cancers. The National Academy of Sciences suggests that everyone should eat a minimum of 130 grams of carbohydrates each day. Do the math. That comes to 520 carbohydrate calories a day.
5. True or false: Low-carbohydrate foods have fewer calories than other foods.
False. The only way to find out whether a low-carbohydrate product also has fewer calories is to read the label. Many manufacturers are cutting carbohydrates from their products while loading them up with fat -- and without reducing the calories. A calorie is a calorie, whether it's from carbohydrate, protein, or fat.
Beware of terms such as "net carbohydrates," "impact carbohydrates" and "effective carbohydrates." These terms are not defined by the Food and Drug Administration, and are used by food manufacturers to cash in on the current carb phobia. Whatever the manufacturers call it, this is supposedly the amount of carbohydrate that's left after you subtract those carbohydrates said to have a negligible effect -- such as fiber, sugar alcohols, and glycerin. Until the government defines these terms and research supports the assumptions behind them, my opinion is that these are useless words that do little more than confuse consumers. Read labels, and choose foods that are low in sugars but rich in fibers for the healthiest carbohydrates.
Now that you're an expert on carbohydrates and calories, you can better make sense of food labels. Calories, along with fat grams, protein grams, and carbohydrate grams, are listed in the nutrition facts panels of most commercial food products.
When in doubt, I go to the U.S. Department of Agriculture's online nutrient database (called the USDA National Nutrient Database for Standard Reference). This extensive database allows you to choose the portion size, and provides not only calories but a whole host of nutrients contained in the food.
Most Weight Loss Clinic eating plans will provide at least half of the total calories from carbohydrates. Choose your carbs wisely. Healthy carbohydrates that contain plenty of fiber (2-3 grams per serving) not only aid in digestive health and keep things moving along, but they also fill you up and help keep snack attacks at bay.
Originally published Monday, August 02, 2004
Medically updated July 26, 2005.
©2005 WebMD Inc. All rights reserved.