Plant Foods in the American Diet? As We Sow…

The iconic and seemingly irrepressible “typical American diet” is a paean to plant foods – unfortunately, not the right kinds of plants. We don't seem all that interested in the variety with leaves, roots, and stems. Rather, we have shown far greater digestive devotion to the kind of plant that comes equipped with an assembly line, than to the variety with xylum and phloem. Factories that process food, and factory farms that use what might have been food as feed to fatten what then becomes food exert a dominant influence on the modern American foodscape, and our diets.

We eat fewer fruits and vegetables than we should. The reason there is a “should” at all is the only reason that justifies any dietary guidance: food matters to health. That we are what we eat is as irrefutably true as it is inscrutably hard to see. Just as we extract lumber from trees to build houses that don't resemble the woods, so we extract nutrients from foods to replace the cells we turn over each day by the millions, or to construct the growing bodies of children. What we eat matters.

And of all that we eat, plant foods direct from Nature have the potential to matter most. Although there is some debate about the magnitude and specificity of influence of plant foods on health outcomes,[1] the general consensus and weight of evidence tip decisively in favor of diverse health benefits from eating more plant-based diets.[2–6] Were we to eat more plant foods, and relatively less of all the rest, health, both public and personal, would almost certainly improve.[7]

We have, therefore, long been admonished to eat more fruits and vegetables. We have been cajoled by the “5-a-Day” program, recently upgraded to “more matters,”[8] since 1991. The current program enjoys the support of the non-profit Produce for Better Health Foundation.[9] More fruit and vegetable intake figures among the objectives of Healthy People 2010.[10]

The federal government has been convening experts to generate nutrition guidance since 1978, with release of the first dietary guidelines for Americans in 1980.[11] Those original guidelines called for a variety of foods, with fruits and vegetables topping the list of recommendations. By 1990, a diet with “plenty of” vegetables and fruits was recommended. By 2000, a “variety” of fruits and vegetables was recommended for each day, and the trends in dietary guidance over 20 years[12] revealed the increasing emphasis on eating food from plants. In the current guidelines, released in 2005,[13] vegetables and fruits have marquee status as the principal food groups to “encourage.”

Perhaps for 2010, the Dietary Guidelines Advisory Committee[14] will just cut to the chase by embracing the wisdom of the Bard regarding the soul of wit, and the wit of Michael Pollan regarding the soul of dietary guidance: “Eat food. Not too much. Mostly plants.”[8] Whether our dietary guidelines get quite that pithy, an increasing emphasis on food from plants is certain.

Despite these ever more heaping servings of dietary guidance, no one, it seems, has much stomach for the stuff. We are not eating more fruits and vegetables. We had ample cause to suspect that and lament it before now, but our lack of progress has rarely if ever been illuminated as clearly, and discouragingly, as Kimmons and colleagues[15] have now done.

Kimmons and colleagues, with the Centers for Disease Control, used dietary intake data from 2003–2004 based on 2 days of dietary recall in a nationally representative sample of over 5500 participants (adolescent and adults) in the National Health and Nutrition Examination Survey. They compared fruit and vegetable intake to recommendations. But rather than contrasting consumption patterns with one-size-fits-all guidance, they compared against the guidance in MyPyramid,[16] which adjusts fruit and vegetable guidance so that it is proportional to calories.

Their findings were, in a word, dreadful, although at least nondenominationally so. Across all demographics, fruit and vegetable intake was deplorably low. Even educational status did not seem to make much difference. And as fruit and vegetable intake recommendations rose with caloric intake level, so, in general, did distance from the target.

The details are hard to articulate without choking on them. Less than 1% of adolescents, roughly 2% of men, and only 3.5% of ostensibly more sensible women met guidelines for both fruits and vegetables. And this is despite counting jam, jelly, and orange juice as fruit, and both French fries, and the ketchup poured over them, as vegetables. In fact, orange juice was the dominant fruit choice, and potatoes the dominant vegetable across all demographics. And if we dare, let's add insult to injury and note that the recommendations are low to begin with, aiming for feasible rather than optimal.

Why are our recommended daily cups of vegetables and fruits so clearly more than half empty? There are many reasons, and along with other investigators, my colleagues and I have had a chance to ascertain some of them.[17] Cost is a factor. So is convenience. And culture. Real men who won't eat quiche certainly won't be caught dead nibbling daintily on a salad.

Processed foods are generally less expensive, last longer, and are less likely to disappoint. Not every peach tastes just as hoped, but every cheese puff probably does. We provide advice for more fruit and vegetable intake in a society that produces and markets tens of thousands of foods in bags, boxes, bottles, jars, and cans; that subsidizes the growth of corn to produce high fructose corn syrup; and that measures value as calories, rather than nutritional quality, for the dollar.

Kimmons and colleagues are right that it will require a multifaceted approach to advance the plant-food agenda. In fact, we probably need to change just about everything.

We need financial incentives for buying plant foods, and perhaps financial disincentives for the purchase of assiduously processed vehicles for empty calories. We need real men to get in touch with their fennel side, and culturally sensitive guidance for the inclusion of fruits and vegetables in any daily routine or ethnic diet. We need a campaign to change a core cultural value, and recognize that nutrition for the dollar is a far better measure than calories. In a society prone to epidemic obesity, maximizing calories per dollar spent simply means getting fat at minimal charge.

And perhaps, while waiting for the aggregation of programs and policies that will be needed to move this dial, we can nudge diets gently in a salubrious direction by better identifying the proximity of processed foods to nature. Consumers may find themselves inching up to the produce aisle, one insight at a time. My own efforts suggest this may be pursued in schools,[18] and supermarkets.[19]

What will it take if we wish to see our efforts blossom into better diets and better health? We must tirelessly till the resistant soil of policy change. We have long sown but frugal seeds of limited programs and modest policies to promote fruit and vegetable intake, and sown them on ground relatively infertile to such efforts. The foodscape is dominated by processed foods, and subject to the agricultural imperatives of a farm bill that is more about big business, than the health of the little guy.

To reap the rewards of better health that will likely ensue when we eat mostly, or at least just more, plants – there's a whole lot of sowing to be done.