Q. I recently read that eating white rice, white pasta, white potatoes and white bread is not good for you. I am writing simply because I like these foods. Can you please tell me if I am actually harming myself by eating these white foods?

A. Nicola McKeown, PhD, director of the nutritional epidemiology program at Tufts’ Friedman School, has focused on examining carbohydrates and cardiovascular disease risk, and her advice is to focus on nutritional quality. She says, “For many of us, it can be challenging to turn down crusty white bread or mashed potatoes, and eating brown rice or whole wheat pasta may just feel strange! As children, we were likely exposed to these types of carbohydrates, and this makes it challenging to change our preferences as adults. Potatoes and refined carbohydrates (white pasta, white flour breads and desserts, white rice) are complex carbohydrates that provide the body with energy to go about daily activities. If the question is are these carbohydrates the optimal choice, however, the answer is no.

“Eating refined grains on an occasional basis, because you enjoy them, is not likely to harm you provided these refined grains are not your sole source of carbohydrate. Unfortunately, most American adults consume four to six servings of refined grains per day but less than one serving of whole grains daily. Research has found that people who eat more refined grains gain more weight over time, and this can lead to health complications in some individuals.

“Dietary fiber is linked to a host of health benefits, yet most refined grain foods and products are low in fiber. It is also important to keep in mind that not all whole grains are rich in fiber, so eating a variety of whole grains is best. Farro, bulgur and Kamut are great examples of fiber-rich whole grains. Over time, you may find that your taste buds will grow fond of whole grains.

“As for white potatoes, the physiological effects of potatoes can vary considerably depending on whether they are mashed or baked, served hot or cold, fried or not, served with sour cream or mashed with butter. Eating your potatoes with the skin on provides extra fiber, vitamin C and potassium, but topping with butter, sour cream or cheese diminishes nutritional quality.”

Consider sometimes substituting sweet potatoes, she advises. “They are rich in beta-carotene, and they contain double the amount of dietary fiber.”