Most Americans Are Not Meeting Cancer-Preventing Dietary Guidelines

The majority of Americans do not eat a diet that meets national dietary guidelines for preventing cancer, according to a new study.

The researchers found that about 70% of adults didn’t eat enough fruits, vegetables, and whole grains. The majority of participants didn’t get enough fiber in their diets.

The study, which was published in the Journal of the Academy of Nutrition and Dietetics, analyzed the self-reported eating habits of more than 30,000 American adults, along with their body mass index (BMI).

The data used was from the National Health and Nutrition Examination Survey (NHANES), which collects health information on a nationally representative sample of Americans each year. Researchers analyzed the diets of participants over a 24-hour time period.

Nearly 70% of the people included in the study were classified as overweight or obese, based on their BMI. The researchers found that adults in the obesity range were significantly less likely than others to meet recommended daily amount of fiber, fruit, non-starchy vegetables, and whole grains.

On average, people across all BMI classifications ate more added sugars than is recommended.

“The findings are not surprising at all,” Jessica Cording, MS, RD, dietitian and author of "The Little Book of Game-Changers," tells Verywell. “It’s pretty well established that the standard American diet is not supportive of cancer risk reduction.”

Sonya Angelone, RDN, a spokeswoman for the U.S. Academy of Nutrition and Dietetics, agrees. “It is unfortunate that the public is not getting the simple message to eat more fruits and vegetables and whole grains to decrease the risk for disease, including cancer,” she tells Verywell.

National Dietary Guidelines for Cancer Prevention

The cancer-prevention dietary guidelines are established by the American Institute for Cancer Research and American Cancer Society and are similar to the Dietary Guidelines for Americans.

The guidelines suggest people should:

• Eat at least 2 ½ to 3 cups of vegetables a day
• Have 1½ to 2 cups of fruit each day
• Strive to eat 30 grams of fiber a day
• Have at least half of your grains be whole grains
• Limit red and processed meats to less than 18 ounces a week
• Get less than 10% of your daily calories from added sugars

Why People Aren’t Meeting Cancer-Preventing Dietary Guidelines

The study didn’t explore why study participants weren't eating as well as they should, but dietitians share a few theories.

“It is multifaceted,” Keri Gans, MS, RD, author of "The Small Change Diet," tells Verywell. “Some people hardly cook at home. They order in or grab take-out and they just either don’t choose or find fruit, veggies, or whole grains as part of the offerings.”

Eating produce and whole grains “takes planning since it is not usually included in overly processed, convenience foods,” Angelone says, adding, “these are the types of foods more people are eating because they are so readily available and inexpensive, for the most part.”

Fresh fruits and vegetables are perishable and need to be purchased frequently, she points out. “If these foods aren't readily available in your kitchen, they won’t be included in the foods people are eating,” she says. With these perishable foods, “people either find them too expensive or are simply tired of wasting money on them because they may go bad quickly,” Gans says.

The standard American diet also “tends to be very high in added sugar and low in fruits and vegetables—that’s not very helpful,” Cording adds.

There is also an issue with perception, Gans notes. Some people may also think they’re eating enough fruits, vegetables, and whole grains, but actually aren’t having enough.

How to Improve Your Diet

Dietitians have a slew of recommendations for eating cancer risk-reducing a diet:

• Focus on convenience. The more convenient healthy food is for you, the more likely you’ll eat it, Cording says. “Frozen produce is a really good starting place because it tends to be more affordable and it reduces food waste,” she says. Gans is also a fan of canned produce. “Canned and frozen [options] are made with produce at peak ripeness and can be just as healthy, if not healthier, then ‘fresh,’” she says.
• Eat fresh fruits and vegetables that are in season. “They usually taste best at their peak and are less expensive than at other times of the year,” Angelone says.
• Portion your plate. “Fill half your plate at dinnertime with veggies, while the other two quarters with protein and carbohydrate,” Gans says.
• Make fruits and vegetables a priority. “Start the meal with a fruit or vegetable appetizer,” Angelone suggests.
• Set healthy goals. Angelone recommends having one fruit with breakfast, a fruit and vegetable with lunch, a vegetable as a snack, and two vegetables with dinner.
• Add fruits and vegetables to everything. “You definitely can add veggies to pasta dishes, omelets, sauces, soups, stews, and casseroles,” Gans says.
• Experiment with whole grains. “Start by slowly experimenting with new grains, such as barley, quinoa, or buckwheat, until you find one you truly love,” Gans suggests