Published January 22, 2014
She said that eating your spinach would make you smarter and that carrots would improve your eyesight. When you were a (well-behaved, respectful) kid, you listened. But now that you’re feeding yourself, should you be following all the advice that Mom dished out? To learn the truth, Real Simple consulted a panel of nutrition pros. While they didn’t always agree, their opinions will give you—and your mother—something to chew on.
Spinach Is Brain Food
Tara Gidus, registered dietitian and nutrition consultant based in Orlando, Florida, and the author of the book Pregnancy Cooking & Nutrition for Dummies: "Absolutely! Spinach is loaded with lutein, folate, and beta-carotene. These nutrients have been linked with preventing dementia. I know neurologists who recommend eating spinach at least three times a week."
Dawn Jackson Blatner, registered dietitian in Chicago and the author of The Flexitarian Diet: "Spinach is super nutritious, potentially anti-inflammatory, and good for heart health. However, there are foods that are even better for the brain, such as blueberries, which are full of antioxidants; eggs, which contain choline, a compound that can help maintain healthy brain-cell membranes; and coffee, which enhances alertness and concentration."
Katherine Tallmadge, registered dietitian; the president of Personalized Nutrition, in Washington, D.C.; and the author of Diet Simple: "You could consider spinach a brain food because it contains antioxidants and phytochemicals that help improve blood flow and reduce inflammation. Good blood flow is critical to brain function. But the best brain food is salmon. Its omega-3 fatty acids are highly correlated with reductions in dementia, Alzheimer’s, and depression."
Related: The Truth About 12 Health Myths
You Should Eat Only When You’re Hungry
Tallmadge: "That’s technically true, but it’s practically impossible to follow when you’re in a society where food is everywhere. And the idea of not eating all day if you’re not hungry isn’t right, either, because then you can overeat at dinner, when you’re suddenly ravenous."
Blatner: "This is a tricky one. If we wait to eat until we’re hungry, we may not have access to healthy food when we need it. I recommend using a clock as a gauge: Eat every four to six hours, and eat until you feel satisfied, not uncomfortable and stuffed."
Keri Gans, registered dietitian in New York City and the author of The Small Change Diet: "If only people knew when they were hungry! The average person doesn’t. It’s so hard to tune in to your hunger because over the years other factors—like feelings, habits, and moods—start affecting when and how you eat. In general, you should eat every four to five hours. Any more than five and you will get extremely hungry and end up overeating at your next meal."
Related: Numbers to Live By
Bananas Are Nature’s Perfect Food
Tallmadge: "That’s far from the truth. As a fruit, bananas are okay in terms of nutrient content, but berries are at the top of the scale. To get the most nutritional value from your fruits and vegetables, you have to eat the skin and the seeds, and who would want to eat a banana peel?"
Blatner: "Bananas are awesome: For about 100 calories, they’re a good source of vitamin C, B6, potassium, and fiber. Of course, they’re not going to meet all your nutritional needs."
Gidus: "I don’t like to call anything perfect. But I do believe everybody should eat a banana every day, because it’s a great source of potassium, which helps control blood pressure. Also, bananas and potatoes have a particular type of fiber called resistant starch: Your body can’t absorb it, so that keeps you full longer and may improve insulin sensitivity and reduce fat accumulation."
Related: Cooking Myths Debunked
Carrots Improve Your Eyesight
Keith Ayoob, Ed.D., registered dietitian and an associate professor of pediatrics at the Albert Einstein College of Medicine, in New York City: "There’s a load of vitamin A in carrots, and a deficiency can cause blindness. But I don’t think I’ve ever seen that in this country. Vitamin A is pretty easy to get from all fruits and vegetables, at least enough to keep your eyes functioning well."
Blatner: "That’s technically not true. The beta-carotene may decrease your risk of developing glaucoma and macular degeneration [a leading cause of blindness in the elderly] and help with night vision, but it doesn’t help you see better during the day. Don’t expect to ditch your glasses just by eating a lot of carrots."
Gans: "If you were deficient in vitamin A, carrots would help make your vision better, but that’s not to say they would make it great. If you have normal levels of vitamin A, eating carrots won’t make a difference."
Eat Breakfast Like a King, Lunch Like a Prince, and Dinner Like a Pauper
Tallmadge: "I believe people are more likely to maintain their health if they eat this way. And there’s a lot of research that backs this up, particularly how not skipping breakfast has a positive effect on weight."
Ayoob: "It’s valid advice. A lot of people don’t feel hungry for breakfast because they’re eating too much at night. But you’re better off consuming more calories, including some extra protein, in the morning. It satisfies your appetite, so you won’t be so hungry at night, and you’ll have the nutrients and energy when you need them."
Leslie Bonci, M.P.H., registered dietitian and the director of sports nutrition at the University of Pittsburgh Medical Center for Sports Medicine:"But some people want to be royal all day long, and you have to take the crown off at some point! It really depends on when in the day you’re most active. That message can’t be one-size-fits-all."
Anything You Eat After 8 p.m. Turns Into Fat
Bonci: "There are a lot of countries in the world where people sit down to eat dinner at 10 p.m., and the people are not fat. Ultimately what’s important is your total calories, not when you eat them."
Ayoob: "If you’re not going to use the energy from the food you eat right away, your body will turn it into fat or glycogen [stored carbohydrates]. But that’s true of what you eat any time of the day. Your body will access those stores and use them if it needs to."
Gans: "If you ate all the calories your body required to maintain your weight by eight o’clock, then anything you eat after that will be excess and will turn into fat. Otherwise it won’t. The problem is, people often overeat later because they didn’t eat throughout the day. Or they graze out of habit or boredom. I tell them to adopt an earlier bedtime."
Food Cravings Are a Sign That Your Body Needs Certain Nutrients
Ayoob: "It depends on what you’re craving. If the craving is for cupcakes, it’s probably psychological, not physiological. But sometimes people have cravings for specific foods that could indicate a minor nutrient deficiency. For instance, if you regularly crave something salty after exercise, it may be because you need to replace potassium or sodium, minerals that are lost through sweating."
Tallmadge: "That’s the silliest myth of all, especially as most cravings are for chocolate, chips, or ice cream. Cravings are usually irrational, they’re often for comfort foods, and they’re typically the result of underfeeding yourself and then seeing or smelling something sweet or fatty or salty."
Bonci: "Nope, with the exception of the disorder pica [a yen for a nonfood item, like dirt or paper, which could indicate an iron deficiency]. Usually food cravings are psychological—they don’t mean your body needs Godiva. People assume that a craving is just for a particular taste, but it’s often for a taste, a temperature, or a texture. My advice is to incorporate some of the foods you crave into your weekly diet in planned, controlled amounts."
All the Nutrients Are in the Skin of the Potato
Ayoob: "There are nutrients and fiber in the skin. That’s true of fruit skins, too, like apple peels. Wherever the color is, that’s where most of the antioxidants, minerals, and good nutrition are."
Gans: "The skin contains fiber, but the flesh is important, too. It’s loaded with potassium, magnesium, vitamin C, and folate. So eating the whole package is the way to go."
Tallmadge: "Not all the nutrients are in the skin, but some of them are. Ounce for ounce, the skin is definitely superior to the flesh, since it contains more calcium, iron, and fiber. That’s why I tell people to scrub the skin and eat it along with the rest of the potato."
Spicy Foods Help You Lose Weight Because They Speed Up Your Metabolism
Bonci: "Some studies suggest that consuming spicy foods that contain capsaicin [the compound that makes chili peppers hot] can have a thermogenic, or fat-burning, effect, but it’s negligible. So you can’t have a Big Mac and a jalapeño chaser and expect to drop pounds."
Gans: "I don’t believe there’s a food that will speed up your metabolism significantly enough to make a huge difference. Some people find that spicy food helps them eat less—they get satisfied more quickly because the food has a lot of flavor. So it may help by causing you to reduce your overall food intake."
Blatner: "There might be some truth to this. Research has shown that foods with capsaicin may elevate metabolic rate by 23 percent. But the catch is, you may need to add a tablespoon of, say, hot peppers to each meal, which is not realistic. Also, the effect is short-lived, and the boost you get is small. The average person would burn only about 50 additional calories a day."
An Apple a Day Keeps the Doctor Away
Tallmadge: "I would change that to “Five fruits and vegetables a day keep the doctor away.” Apples are great for you, but you want a variety of produce in your diet. People who eat a lot of fruits and vegetables have significantly reduced rates of cancer, heart disease, diabetes, and gastrointestinal disorders."
Blatner: "I kind of want to say yes to this one. Apples are such a nutritious snack and such a portable, easy way to get a serving of fruit into your daily diet. I think it’s worth marketing them that way."
Gans: "If only it were that simple! Apples are wonderful, nutrient-rich foods, but one piece of fruit a day won’t do it. It’s the whole package of healthy eating and exercise that helps keep the doctor away."