BY KAAREN COLLINS, MS, RD, CDN
BY KAAREN COLLINS, MS, RD, CDN
Q: Is there much difference in the nutritional value of different kinds of lettuce?A: Yes. Although iceberg lettuce makes a crunchy bed for other vegetables, it is low in nutrients compared to other greens. A cup of Boston or bibb lettuce provides three times as much vitamin A. Loose leaf lettuce is even richer in nutrients, offering six times the vitamin A of iceberg lettuce and a fair supply of vitamin C. Adding even more nutrition, romaine lettuce provides eight times the vitamin A and six times the vitamin C of iceberg lettuce. You can boost the nutrition in your next salad by including raw spinach, an even higher source of vitamin A that also provides lutein and other carotenoids linked to eye health. Both romaine and spinach are good sources of folate, a B vitamin that seems to lower the risk of at least some forms of cancer. Laboratory tests at Cornell University identify spinach among the highest in antioxidant activity and the ability to block cancer cell growth.
Q: How much dietary fiber are we supposed to eat each day?A: The most recent recommendations come from the Institute for Medicine, the group that sets Recommended Dietary Allowances (RDAs) and the new Dietary Reference Intakes (DRIs). These recommendations recommend adult women get 25 grams of fiber daily until age 50, when 21 grams is thought a reasonable goal. Men are advised to aim for 38 grams a day until age 50, when 30 grams of fiber is said to be adequate. At one time, experts suggested that children get an amount of fiber equal to their age plus five (a 7-year-old would aim for 12 grams of fiber). But the new recommendations call for higher levels for youth: 25 grams a day for ages 4 through 8, and 26 to 38 grams a day after that, depending on age and gender. Dietary fiber helps to keep the digestive tract functioning, control blood sugar and blood cholesterol, and reduce colon cancer risk. These new recommendations were set at the lowest level thought to offer heart disease protection. To achieve these goals, the plant-based diet advocated by the American Institute for Cancer Research is essential. This means several servings of whole grains and at least five (ideally seven to ten) servings of fruits and vegetables daily, as well as frequent use of dried beans, nuts, bran, and other sources of fiber.
Q: Is it safe for teenagers to be vegetarians? My son has been exhausted since he became one.A: Vegetarian eating is safe, but it poses a special challenge to teenage boys because of very high calorie needs during growth. Since vegetarian eating, with its emphasis on grain products, fruits, and vegetables, contains so much bulk, it can be difficult for those with high energy needs to eat enough. Without the fat otherwise found in meats, there is room for oil, margarine, and salad dressing several times daily as a source of calories and needed fat. Another problem may be inadequate protein. We donât need meat for protein, but just eating more pasta and fruit wonât meet needs. A teenage boy needs two to three daily servings of âmeat alternativesâ that supply the protein and minerals such as iron and zinc found in meats. One serving might be a half-cup of beans in chili, soup, or salad; a quarter-cup of nuts or seeds; one egg; or two tablespoons of peanut butter. Perhaps heâd like to try some of the veggie burgers and vegetarian versions of foods, like chicken nuggets or sausage, available in grocery freezer sections. These âmeat alternativesâ are needed in addition to the three servings of milk products needed each day to provide the calcium (as well as protein) that teens need. If he tries all these suggestions and still seems more tired than usual, check with his doctor for other possible problems.
Q: What is the most nutritious vegetable?A: When we first realized the health impact of antioxidants like vitamin C and beta carotene, the âbestâ choices seemed to be those that are very dark green (like spinach, broccoli, collard and other greens), deep orange (carrots and sweet potatoes), or high in vitamin C (including cauliflower and sweet red peppers). But beta carotene is not the only carotenoid with important health-promoting abilities. Now attention is also being given to sources of lycopene (found in red produce, like tomatoes) and other phytochemicals, natural substances found in all plant foods. Once research on phytochemicals discovered their power to block various stages of cancer development and promote other aspects of health, the definition of a ânutritiousâ vegetable changed, especially when it became clear that vegetables differ in the kind and amount of phytochemicals they contain. For example, onions, garlic, and cruciferous veggies like broccoli, cauliflower and Brussels sprouts contain the phytochemicals called organosulfides, which fight cancer in certain ways. Citrus fruits rich in flavonoids can protect against cancer in other ways. Healthful phytochemicals have now been found in almost all veggies, so the best strategy is to eat a wide variety of vegetables, and eat them abundantly.
Q: What is the difference between the terms âother carbohydrateâ and âtotal carbohydrateâ found on food nutrition labels?A: âOther carbohydrateâ refers mainly to complex carbohydrates, commonly called starches. This is the main type of carbohydrate in breads, pasta, potatoes, and starchy vegetables like corn. âOther carbohydrateâ also includes sweeteners called sugar alcohols (xylitol, mannitol and sorbitol) that may be present. In addition to âother carbohydrate, âtotal carbohydrateâ includes dietary fiber (undigestible carbohydrate) and sugars, including added sweeteners like table sugar and corn syrup, as well as naturally occurring sugars in fruits and dairy products.
Q: Are packaged multigrain cereal bars a nutritious choice?A: Just calling something multigrain makes it sound nutritious, but that simply means that itâs made from more than one type of grain (perhaps wheat and oats). These bars are not high in fiber; in fact most bars have about the same fiber as a slice of white bread. And seeing fruit in the name makes it sound like a very portable way to get one of those all-important servings of fruit, but these bars are generally more like half an English muffin spread with some margarine and a whole lot of jam. The packaging makes these bars convenient, but nutritionally youâd get a whole lot more from a bowl of whole-grain cereal with fruit and milk, or a slice or two of whole wheat toast spread with peanut butter, with a piece of fruit and glass of low-fat milk on the side.
Q: My 4-year-old is getting a little âchunky.â Should I do something about his weight?A: With todayâs skyrocketing problem with childhood and teen obesity, you are right to be concerned. But do not put your child on a diet. A child who feels deprived of food is more likely to begin a lifetime of yo-yo dieting. Your preschooler may have an inherited tendency for a larger build, or he may be temporarily carrying a bit of extra fat that will slowly decrease with time. But now is an ideal time to examine your familyâs lifestyle. The number one factor linked to higher body fat in children is a sedentary lifestyle. Experts suggest limiting all kidsâ television, video game, and computer time to a total of no more than two hours daily. Encourage your children to become fit and active adults by establishing a tradition of family recreation like biking or hiking; introduce your children to individual and team sports when they are ready; invite their friends over to take part in active play with your child. As for eating habits, make sure that you are not using food as a reward or as a tool to relieve boredom. Beyond milk and juice in amounts to satisfy basic nutritional needs, make water the beverage of choice for thirst instead of endless amounts of juice, fruit drink, or soft drinks. Provide meals that offer a balance of protein, grains, fruits, and vegetables. Teach your son now to judge the amount he eats by his own hunger signals; do not rope him into the âclean plate club.â
Q: Is âsun teaâ safe to drink?A: No. Tea brewed by sitting in the sun for several hours is not a good idea because of the increased risk of bacterial contamination that could result in nausea, diarrhea, and intestinal cramps. Although tea leaves naturally contain small amounts of bacteria, fixing tea by steeping it in hot water for only a few minutes does not allow enough time for microbes to multiply and cause illness. When tea steeps in the sun for hours, however, conditions are ideal for bacteria to multiply rapidly and pose a significant risk of sickness. Iced tea prepared from brewed tea should be steeped in boiling water for three to five minutes and then refrigerated immediately. Leaving a pitcher sitting on the counter (to pour over ice as needed) also provides an ideal environment for bacterial growth.Karen Collins is a registered dietitian with the American Institute for Cancer Research