A: In brief, absolutely yes, but questioning this notion is understandable in our current era of fearmongering about foods - processed meats one week, potatoes and corn the next.
Let's get straight to the facts.
Think of foods as packages of nutrients with varying amounts of the three calorie-containing nutrients: carbohydrates, protein and fat. For example: In their natural form, fruits and vegetables contain mainly carbohydrates with a bit of protein and nearly no fat. Legumes and fat-free milk contain mainly carbohydrates and some protein.
There are three types of carbohydrates in foods: starches, sugars and dietary fiber. Foods that contain carbohydrates fall into two main groups.
More-healthful sources: fruits, vegetables, legumes, whole grains and low- or no-fat dairy foods. Less healthful sources: refined grains (most pizza crust, most bagels, muffins and pastries), sugary drinks and sweets.
Carbohydrates become the body's primary energy source, glucose, once it's digested. In addition to energy, healthful sources of carbohydrates offer myriad vitamins and minerals, several which are characterized as called "shortfall nutrients" - those we don't eat enough of - in the 2015 Dietary Guidelines Advisory Committee report. On the list: vitamin A, vitamin D, vitamin E, vitamin C, folic acid, calcium, magnesium and fiber.
The notion that Americans eat a high-carbohydrate diet (and that this is one of the reasons for our excess pounds) doesn't stand up to the stats. Data from the most recent (2011-12) What We Eat in America survey, done by the Department of Health and Human Services and the Agriculture Department, show that American adults get about half of our calories from carbohydrates. This count has remained fairly constant over the years.
Getting 45 to 65 percent of your calories from carbohydrates remains the recommendation from the 2002 Dietary Reference Intake from the Institute of Medicine. Based on this long-standing advice, Americans eat, at most, a moderate amount of carbohydrates.
And regarding weight control, numerous studies conducted over the past decade or so show that low-carbohydrate weight-loss plans aren't more effective for weight loss, especially when the studies follow people long-term.
The more critical issue is the quality of carbohydrate-containing foods we eat. Yes, we have a quality-control problem! People generally are heavy-handed with those less healthful sources of carbohydrates. No surprise: Many 20-ounce servings contain 15 teaspoons of added sugars. Due to a growing body of research pointing to the negative health effects of excess added sugars, including weight gain, Type 2 diabetes and risk factors for heart disease, the FDA has proposed two changes in the next iteration of the Nutrition Facts label to help you more easily identify and quantify added sugars in foods and beverages.
And, even worse, we eat too few servings of more-healthful sources of carbohydrates.
Questions do arise from time to time about whether all healthful sources of carbohydrates impact the body the same. A recent study using the Harvard T.H. Chan School of Public Health's large observational database showed that, over a period of 24 years, people who reported eating more starchy vegetables tended to gain slightly more weight.
So, should you give up starchy vegetables? "I hate to see the shaming of potatoes, peas and corn. We've got a long way to go before we meet daily vegetable recommendations. Focus on upping all types of vegetables, even the starchy varieties," Janet Helm, a registered dietitian/nutritionist and author of the blog Nutrition Unplugged, told me in an e-mail.
A smart eating plan
There are four main quality-control tactics you can take, from the 2010 Dietary Guidelines: - Reduce added sugars. - Limit refined grains, especially those with added sugars, saturated fats and sodium. - Eat more fruits and veggies. - Make at least half of all grains-based foods whole grains. More specifically, at 2,000 calories a day, an average intake recommended for many Americans, the Healthy U.S.-Style eating pattern provided in the 2015 Dietary Guidelines Advisory Committee report suggests these counts: - Fruit: 2 cups per day. - Vegetables: 2 1/2 cups per day. - Legumes: 1 1/2 cups per week. - Grains (all types): 6 ounces per day. - Dairy: 3 cups per day.
Added sugars? Limit those to 7 1/2 teaspoons per day.
In summary, yes, you can eat carbohydrate-containing foods at every meal, but, (isn't there always a "but"?) as with all foods, practice portion control. I spend my allotted calories on nutrient-packed foods of carbohydrates - such as the sweet potatoes I smell roasting now.
Warshaw, a registered dietitian and certified diabetes educator, is the author of numerous books published by American Diabetes Association, including "Eat Out Eat Well: The Guide to Eating Healthy in Any Restaurant," and the blog EatHealthyLiveWell found on her Web site, www.hopewarshaw.com.