A registered dietitian answer the most common questions asked about food.
Q: I don't like veggies. Is it okay to get my five-a-day from fruit only?
A: Fruits and vegetables contain about the same vitamins and minerals, but vegetables offer a wider array of compounds that we think protect you from cancer, heart disease, and more, explains Cindy Moore, RD, of the American Dietetic Association. For instance, broccoli and other cruciferous vegetables—but not a single fruit—are packed with sulphoraphane, which appears to fight breast cancer. It's okay to doctor your veggies with a tablespoon of grated cheese or a pat of butter.
Q: If you drink 100% juice, is it as good for you as a whole fruit or vegetable?
A: Yes and no. On the plus side, juice may contain more nutrients than a single piece of produce. An 8-oz glass of orange juice has 100 mg of vitamin C; an orange has 75 mg. But juice offers almost none of the fiber found in produce, and it packs calories. An 8-oz glass of orange juice has 120 calories and 0 g of fiber; an orange has only 60 calories and 3 g of fiber. The bottom line: Make sure that you mostly eat whole produce.
Q: I could swear that I'm addicted to sugar? Is this possible?
A: Not the way you can be addicted to a drug. But sugar triggers the release of opiates in the brain, which makes you feel good. Unfortunately, eating too much sugar is a recipe for weight gain. Start learning to rely on fruit. It offers naturally occurring sugar—but less than what's in most added-sugar treats—plus vitamins, minerals, and fill-you-up fiber.
Q: If the orange juice label says "not from concentrate," does that mean it's better for you?
A: Not really. "Not from concentrate" juice is nutritionally almost identical to its "from concentrate" counterpart. One caveat: Orange juice that isn't from concentrate may not be pasteurized (put through a heating process that kills dangerous bacteria such as E. coli). So if you do opt for the not-from-concentrate variety, check the carton. The FDA requires unpasteurized juices to carry warning labels.
Q: Is there a way to estimate the calories in fruits and vegetables?
A: Sure, and it's easy. On average, one small piece or ½ cup of fresh fruit contains about 60 calories. Starchy veggies such as potatoes and corn average 50 calories per ½ cup, while all other veggies such as broccoli and tomatoes average just 25 calories per ½ cup. These are great calorie bargains—especially if you're following Prevention's recommended fruit and veggie goal of nine a day.
Q: Can you get too much fiber? Adding up my fiber from all sources, I get 40 g a day.
A: It depends. We recommend 20 to 35 g daily—an optimum amount to prevent constipation, heart disease, and possibly cancer. Getting more fiber than that means that you absorb less of important minerals such as zinc, iron, and calcium. If you're getting extra fiber from eating lots of vegetables, beans, whole grains, and fruit, you probably get enough extra minerals to compensate. But if you're taking a fiber supplement, it could be leaving you short on some minerals.
Q: My teenage daughter wants to be a total vegan, but I'm not sure that's safe. Is it?
A: It can be safe—and even healthy—if she chooses the right foods, advises Judith Stern, ScD, professor of nutrition at the University of California, Davis. "She can't just eat bagels, bananas, and soft drinks," Dr. Stern points out. Three reminders:
- Concentrate on calcium from calcium-fortified orange juice or soy milk.
- Encourage her to eat whole grains, beans, nuts, seeds, and a wide variety of fruits and vegetables.
- Provide her with a multivitamin.
Q: Suddenly, everyone I know is eating pork rinds and beef jerky. What's your opinion?
A: Our advice is to treat them like potato chips—in other words, munch in moderation. The reason: Ounce for ounce, pork rinds and most brands of beef jerky have at least as many calories as potato chips (plus gobs of saturated fat). Eat too many calories from any source, and you'll gain, not lose. (Don't be duped by labels; the serving size for pork rinds may be half that for chips.) If you enjoy jerky, you can find low-fat varieties with fewer calories.
Q: I always take my vitamin with my morning tea. But now I hear that tea can keep some vitamins from being absorbed. Is that true?
A: Glad you asked: Compounds in tea called tannins interfere with absorption of the mineral iron. If your doctor has told you you're low on iron, it's best not to drink your tea within 90 minutes of taking a multivitamin with iron or any iron supplements that have been prescribed for you. But don't ditch your tea: It's a powerful stew of antioxidants that may fight cancer and protect your heart.
Q: I've heard that those high-protein diets can hurt your bones. Is this true?
A: Only if you don't consume plenty of calcium. High levels of protein slightly increase how much calcium your body excretes. But if you're getting extra calcium in your diet, extra protein won't rob you of bone density, says Robert P. Heaney, MD, a calcium specialist at Creighton University in Omaha, NE. How much do you need? If you're on a high-pro diet such as the Atkins diet or the Zone, Dr. Heaney recommends 1,500 to 2,000 mg of calcium daily from a combo of diet and supplements.
Q: I stick to a weight loss plan better if I eat the same thing every day. Is that okay, if the foods are healthy?
A: If that's the only way you can achieve a healthy weight, yes. But you need to do this: Make an appointment with a registered dietitian to make sure that your lineup of foods gives you a broad range of vitamins, minerals, and healthy phytochemicals. Otherwise, you could choose a dozen healthy foods, but every single one might be low in, for example, vitamin C, or zinc, or both!
Q: Is it okay to fast most of the day, then eat just one big meal?
A: Sorry, but no. "Your body needs to be refueled throughout the day," explains Patty Kirk, RD, nutritionist at The Cooper Clinic in Dallas. "Eat just one meal, and you'll be dragging most of the time." And when you consume 50 g of fat at one sitting—easy to do at one big meal—your arteries lose flexibility for the next 4 hours, a period of time that one researcher has described as a "heart attack danger zone." Eat three meals a day or a series of minimeals on a regular basis.
Author: Holly McCord, RD