Cook from scratch. Eat foods in season. Buy locally. That is the conventional wisdom on what Americans must do to become healthier.

Ben Gardner does not agree.

The founder of Linkwell Health knows that Americans, especially those with chronic diseases, should eat better. Consumers with diabetes buy twice as many candy bars and more than twice as much Mountain Dew as their healthy peers, according to the research firm Nielsen, while patients with heart disease buy 10 times as many frozen dinners. But instead of trying to persuade these customers to purchase fresh produce and prepare a home-cooked meal, Linkwell offers them coupons for more healthful frozen dinners or diet soda.

In short, Linkwell doesn't let the ideal be the enemy of better eating, and the strategy is working.

Gardner's approach reflects his background, which is health care, not food. (He admits that for most of his life he was one of those people who would have happily taken a pill to fulfill their nutritional needs, though, he says, "the older I get, the more I enjoy food.") Health insurers had spent decades building sophisticated, and expensive, disease-management programs. And yet, given the skyrocketing rates of obesity and chronic disease in the United States, it was clear that they couldn't compete with slick marketing campaigns for chips, candy, soda and other unhealthful foods. Why not, Gardner thought, steal a page from the food companies' playbook to encourage more healthful eating?

"Instead of sending someone a 100-page booklet, which nobody reads, about how to manage your health, why not just give them a coupon that they can actually use?" says Gardner.

Americans do love coupons. More than 80 percent say they use coupons regularly, according to NCH Marketing, which tracks usage. In 2011, fueled by tough economic times, we redeemed $4.6 billion worth of coupons, a 12 percent rise over the previous year. Most of those, a quick peek through the Sunday papers will prove, are for unhealthful foods: soda, chips and snack cakes instead of low-fat cheese or whole-wheat pasta.

Gardner's task was to target the consumers who most need to change the way they eat. The answer was to utilize an innovative program implemented by — wait for it — the U.S. Postal Service. When you move and file an official Postal Service change-of-address form, you can elect to receive useful discounts on moving trucks, household appliances, furniture and storage. It's what you need, when you need it. (Gardner worked for several years at Imagitas, the company that designed and manages the postal program.)

To target needy consumers, Gardner reached out to health insurers, which have detailed health data on patients who struggle with their weight and diseases. He asked them to include healthful food coupons in their regular mailings. To protect patients' privacy, Linkwell never sees the health data nor do the brands that sponsor the coupons.

Nor can journalists like me, as federal privacy regulations prohibit the health insurers from disclosing the names of customers who receive Linkwell promotions. But anecdotally, the need for curated coupons seems clear.

Heather James, a 34-year-old mother of three in Huntington, W.Va., likes to use coupons. But when she does, she says she ends up with a cart full of Toaster Strudels and pizza rolls rather than fruits and vegetables or yogurt. "We were eating that stuff and enjoying it," she said. "But we're trying to eat better now, so we've had to change."

Over the past four years, Linkwell has partnered with 20 health plans, including EmblemHealth, Humana, United Healthcare and WellPoint, which cover 120 million consumers. To date, the company has mailed about 100 million coupons from well-known brands such as General Mills, Kellogg's, Kraft and Quaker Oats. The take-up rate — the number of consumers who use the coupons they receive — is more than double the take-up for coupons in the Sunday newspaper circulars.

Linkwell also has run pilot programs in which grocery stores offer discounts on fresh produce or seafood. It is experimenting with innovative promotions in which customers who buy a box of, say, Special K get $1 off fresh blueberries.

Orthodox food reformers might shake their heads at some of the "healthful" foods that Linkwell promotes. There are coupons for packaged Hormel Natural Choice deli meats and Smart Balance Buttery Spread, the latter of which author Michael Pollan, a leader in the food-reform movement, might classify as a "foodlike substance." Linkwell does have criteria about what foods it promotes. For example, a food cannot have more than 480 milligrams of sodium per serving and must have two grams or less of saturated fat per serving.

"We realize that Lean Cuisine is not a home-cooked, organic meal," Gardner says. "We are a pragmatic solution that is not letting perfection get in the way of progress."

Nutritionists agree.

"It's small, gradual changes that work best," says Constance Brown-Riggs, a registered dietitian and a spokeswoman for the Academy of Nutrition and Dietetics. "You do have some individuals that can turn everything around and empty their cupboard and load up on fresh fruit and vegetables and never eat anything from a can again. But there are many individuals who are unable to make those kinds of drastic lifestyle changes. The research shows that small changes do make a difference."

Health insurers like the program because it is a simple way to nudge consumers toward better health. But it also encourages customers to open and read their health-care plan information. Humana, for example, says it saw its "open rate" jump from 60 percent to 90 percent over the years it has worked with Linkwell. The coupons are sent out quarterly and also can be downloaded online. A service for mobile devices is in development.

For the brands, Linkwell offers ultra-targeted marketing that the grocery circular can't. Dreamfields Pasta, a specialty item designed for diabetics, says it gets double the redemption on coupons issued through Linkwell because it puts them in the hands of patients who need to manage their blood sugar. Other, more mainstream, brands such as Quaker Oats and Sargento get a kind of halo effect because coupons for their product are packaged with information from a health-insurance company.

The goal, says Gardner, is to help consumers take control of their health. "Health care is a mystery to almost everyone. But coupons are a currency that everybody understands."