03/15/2013 12:01 pm ET Updated May 15, 2013

Is There a Better Way to 5-a-Day?

We're constantly nudged to eat our five-a-day of fruits and veggies but never seem to quite get there. Surveys show that just 14 percent of Americans eat five a day, and the numbers are lower for teens, with only 9.5 percent eating two fruits and three veggies daily.

Are people unaware of the recommendation? Probably not. The five-a-day message has been quite successful, and surveys show that the majority of people are aware that they should eat a minimum of five; it's the details and portion sizes that are less clear.

Is the message poorly delivered, or is the five-a-day so pie in the sky that many people don't even try? Maybe we should set a more realistic, small-step goal -- after all, one would assume that suggesting 30 minutes of exercise biweekly would be more doable than urging a daily session.

Big goals or small steps?

A new study, published ahead of print in Appetite, set out to see if asking students to eat just one more fruit or veggie worked better than encouraging them to eat five a day. The researchers hypothesized that just one more would have better results. Would that be your prediction?

The authors, led by Nadine Ungar, randomly divided 84 psychology students, who started off with under four servings a day, into three groups. The just-one-more group was asked to increase fruits and veggies by one more a day for a week. The five-a-day group was asked to eat five servings, and the control group was told to eat as usual. After the week of treatment, the participants returned their food diaries, and a week later they were asked to fill in a questionnaire again, reflecting their intake post the trial period.

This is what happened: The 84 students ate about 2.5 servings before the intervention. During the intervention, just-one-more participants indeed increased their intake by almost one serving (0.96 serving, to be precise). The five-a-day group increased intake -- 2.5 fruit and veggies servings. The control group, surprisingly, increased intake by 0.7 servings.

One week after the intervention, the just-one-more group went back to almost baseline (fruits and veggies were at 0.27 above base, not significantly different from the controls), while the five-a-day group were at one additional serving.

Five-a-day was more effective, and the researchers state that setting the higher goal -- and a more specific one -- worked better, at least for this group.

Unfair competition

I hear a lot about the struggles people have with eating better, and with getting their kids to eat more veggies. I do feel the pain, but I don't think it has all that much to do with fruits and veggies. Eating veggies and fruits is not like going to the doctor for shots, or even like flossing teeth. It is not something you do just because it's healthy.

People ate fruits and veggies a plenty well before they knew they were healthy (indeed, people once thought tomatoes were deadly poisonous). I think the main reason people don't eat enough fruits and veggies nowadays isn't because they're not tasty, or because they don't know it's good for them.

The main reason, I think, is the competition. The competition, high-caloric density foods and foods that are highly rewarding because of their sugar, fat and salt content, are ubiquitous. They are endlessly promoted and often cost less than fruits and veggies. Combine our natural tendency toward densely-caloric, tempting foods, with greater availability and the allure created by ads, fruits and vegetables turn pale and humble despite their bright colors, wholesome beauty and very appealing -- yet mellow compared with the competition's -- taste.

My suggestion is to inform about the importance of five a day -- it should actually read at least five a day, and has been swapped in the U.S. by MyPlate, on which half the plate is devoted to fruits and veggies -- because knowing the science-based guidelines is imperative. But I wouldn't beg and plead, or even endlessly remind; it's annoying and counterproductive.

Perhaps the most effective way to get the fruit and veggie habit going is to remove some of the competition. If you serve 2-3 vegetable sides and small portions of the protein entrée, and if you present a bowl of strawberries and nothing else as an afternoon snack, there's a much better chance that the fruits and veggies will be welcomed than if you served these together with loads of pasta, fried foods, sweet and salty snacks and other highly-competitive options.

When fruits and vegetables are viewed by themselves, very few people find them objectionable, and many will name favorites. But fruits and veggies are in an unfair competition for stomach share, and since it is quite proven that a more plant-based diet can benefit us all, I suggest we work on removing some of the competition, at least at home.

Competition is usually healthy, but when it comes to salad competing against a hamburger with French fries, the competition makes the healthy choice ever so difficult.

Dr. Ayala

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