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Six myths about nutrition and health

Greg Mably for The Boston Globe

We all have our own food orthodoxies, at least some of which probably embrace the nutrition myths all round us.

Glossy magazines and popular websites promote the latest food fad or offer stern warnings against your favorite treats; your mother calls up with third-hand advice that originated on daytime television or with your great-great-grandmother in the century before last.

It can be confusing and frustrating.

To help clear things up, six local nutrition and health professionals have offered to debunk some of the most common — and, to them, annoying — misconceptions they hear bandied about.

Myth No. 1: Fats and carbohydrates are bad for you.

Fact: Both can be part of a healthy diet, but you should limit saturated and trans fats and processed carbohydrates, according to Kate Sweeney, a registered dietitian who manages the Nutrition and Wellness Service at Brigham and Women’s Hospital.


“The truth really is that carbohydrates themselves are not fattening. Fat itself is not fattening,” Sweeney said. “Too much of anything is fattening.”

Sweeney recommends eating whole foods: fresh or frozen fruits and vegetables with the skins intact and whole grains such as brown rice, quinoa, buckwheat, and whole oats rather than processed carbohydrates such as white bread, white pasta, or white rice.

“Research just came out that shows that whole grains reduce your risk of cardiovascular disease,” she said.

Healthy fats, she said, can come from avocados, nuts, nut butters, olives, olive oil, and flax oil.

“Not all fats are created equal, just like not all carbohydrates are created equal, and lot of them actually help lower your cholesterol,” Sweeney said.

Myth No. 2: Frozen vegetables are less nutritious than fresh vegetables.

Fact: Vegetables are typically frozen at peak ripeness and may be more nutritious than fresh vegetables bought from the produce department out of season, said Joan Salge Blake, a registered dietitian and a clinical associate professor of nutrition at Boston University.

“It’s like having Rachael Ray in your freezer — they’re all prepped and ready to go,” said Blake.


She said that the nutrients in vegetables are not damaged by freezing, but they can be damaged by overexposure to air. And overcooking will cause them to lose some water-soluble vitamins.

And if you’re like many shoppers, Blake said, a bag of frozen broccoli could wind up being a more palatable option than broccoli you bought fresh but then forgot about in the “produce graveyard” in the bottom drawers of your refrigerator.

“When we finally pull it out, it’s no longer that vibrant green, but rather it’s that combat green,” Blake said.


Myth No. 3: Eating later at night causes weight gain.

Fact: It doesn’t matter when you eat; what’s important is how much you eat all day, according to Michelle Davis, a bariatric dietitian in the Weight Loss Surgery Center at Beth Israel Deaconess Medical Center.

Dealing with patients who have often struggled with their weight for years, Davis said, she often hears of strategies that don’t have a solid foundation.

“A lot of people will say, ‘I stop eating at 7 p.m. because if I eat any later than 7 I will gain weight,’ ” she said. “There’s no science, necessarily, behind this cutoff point.”

Late-night eating can be unhealthy, Davis said, because it often includes snacking while watching television, which could include both unhealthy foods and unmeasured portion sizes. But what matters for weight and overall health isn’t the hour when you consume food, but how much you have eaten — and how much you’ve burned off — across the board.


Myth No. 4: Eggs give you high cholesterol.

Fact: Cholesterol levels in the human body tend to be affected less by cholesterol in our diets than they are by the saturated fats and trans fats we eat, according to Tara Linitz, a registered dietitian at Massachusetts General Hospital who also has a master’s degree in exercise science.

Linitz said older research led to concerns about the cholesterol content of eggs, but more recent studies have shown that eating eggs in moderation — up to three or four whole eggs a week, and unlimited egg whites — is not likely to have negative effects.

A whole egg is actually very nutritious, Linitz said: a complete protein that also contains many vitamins and nutrients, including choline, a nutrient that is found in relatively few foods and is currently being studied for a possible link to brain health.

Myth No. 5: Only adults develop high blood pressure and high cholesterol.

Fact: Children as young as 2 can have both conditions as a result of genetics, diet, or a combination of the two, according to Skylar Griggs, a registered dietitian and clinical nutrition specialist for the Preventive Cardiology Clinic at Children’s Hospital Boston.

Griggs said the clinic, the largest in New England for pediatric patients with high blood pressure and high cholesterol, sees patients as young as 2 and as old as 25, many of whom have genetic predispositions to cholesterol abnormalities.


Before putting any child on medication, dietitians at the clinic will attempt to address the problem by changing diet and activity levels, which often involves more than just the child whose blood pressure or cholesterol is elevated, Griggs said.

“It’s very hard for a child to change their dietary habits if the entire family isn’t on board,” she said.

For children with elevated LDL, or “bad” cholesterol, dietitians recommend restricting saturated fats and trans fats. For high triglycerides, another type of fat found in blood, they suggest cutting down on sugar and processed carbohydrates, replacing them with whole grains. For children who don’t produce enough HDL, or “good” cholesterol, they recommend more exercise and more healthy fats.

In each case, Griggs said, dietitians suggest removing the dangerous foods from the home entirely.

“It’s important for parents to understand that purging all those things out of the house removes the temptation,” she said.

Myth No. 6: Counting calories is the best way to lose weight.

Fact: The composition of the foods you eat is as important as the number of calories you take in, said Keri Mantie, a personal trainer, strength coach, and fat-loss coach with a master’s degree in applied exercise science.

Mantie said that too often, people trying to lose weight plan their diets around calorie counts rather than taking a more critical, broader view of what kinds of calories they are putting into their bodies.

“They treat their bodies like calculators, basically, by counting every calorie that crosses their lips,” she said. “Calories do matter, but hormones matter more, and that’s what I try to teach my clients.”


She said a fast-food blueberry muffin might have same number of calories as an omelet packed with vegetables, but the omelet will give you lasting energy and keep you feeling full until lunchtime nears, while the muffin will give you a short burst of energy followed by a crash, as your body quickly burns through the processed sugar it contains. Soon you feel hungry again.

Jeremy C. Fox can be reached at Follow him on Twitter @jeremycfox.