If you’re aiming to trim carbs from your diet, walk away from any and all potatoes. Some low-carb diet plans require you to cut your carb intake down to 50 to 150 grams for the day, explains MayoClinic.com. While both potatoes and turnips contain carbohydrates, potatoes have four times as much. So if you’re carefully monitoring your carb intake, turnips may be a better option for you.
Almost all of the calories in white potatoes and turnips come from carbohydrates. These veggies only have a small amount of protein and fat. A medium-size 4-ounce white potato has a total of 24 grams of carbohydrates -- a little less than 100 calories from carbs. The same amount of turnips, on the other hand, gives you less than 6 grams of carbs, or a minimal 23 calories from carbohydrates.
Most of the carbohydrates in potatoes, nearly 90 percent, are starch; whereas starch only makes up a trace amount of the carbs in turnips. Starch is like a small capsule of energy in your system. It starts breaking down in your mouth and has to go through a bunch of conversions before eventually turning into glucose. Your body relies heavily on a steady stream of glucose, since it is the main source of fuel for every cell. Because starches take a while to get to that point, they give you a steady flow of energy over an extended period of time.
Both potatoes and turnips also have sugar, a simple carb. Turnips actually have almost three times as much sugar as potatoes -- 3.5 grams versus 1.3 grams in 4 ounces. Sugar, often thought of as the enemy, isn’t generally a big concern when it comes from fruits, veggies, grains and other whole foods. But no matter where it comes from, all sugars digest quickly in your gut and turn into glucose almost instantly. This is why when you eat something high in sugar, you’ll get that sudden sugar rush feeling.
Potatoes and turnips also both have fiber, which is a carbohydrate, but it doesn’t add any calories to your diet. Fiber is essential for nutrient absorption and waste removal. The amount of fiber doesn’t vary drastically between potatoes and turnips. A 4-ounce potato has 2.5 grams of fiber, while 4 ounces of turnips provide 2.3 grams. Because you need 14 grams for every 1,000 calories you have in your diet, according to the Dietary Guidelines for Americans 2010, you’ll need 25 grams for an 1,800-calorie diet. If 1,800 calories is typical for you, a 4-ounce portion of potatoes or turnips provides around 10 percent of your fiber needs for the day.
- U.S. Department of Agriculture and U.S. Department of Health and Human Services: Dietary Guidelines for Americans 2010
- USDA National Nutrient Database for Standard Reference: Potato, Baked, Flesh and Skin, Without Salt
- USDA National Nutrient Database for Standard Reference: Turnips, Cooked, Boiled, Drained, Without Salt
- National Digestive Diseases Information Clearinghouse: Your Digestive System and How It Works
- MayoClinic.com: Low-Carb Diet: Can it Help You Lose Weight?
Melodie Anne Coffman specializes in overall wellness, with particular interests in women's health and personal defense. She holds a master's degree in food science and human nutrition and is a certified instructor through the NRA. Coffman is pursuing her personal trainer certification in 2015.