You have to read the book to fully understand this, but in a nutshell, Pollan argues that health claims are usually a sign that a food has been heavily processed, or that nutrients have been added despite a lack of scientific evidence that they, divorced from their natural source, will really do any good. You don't see many labels with health claims in the produce section, he notes, though that's where the healthiest foods are.
But health claims drive sales. Just look at what "low carb" labels did for sales, albeit for a relatively brief time.
It's just that kind of particular claim that works best, according to an article at Food Business News. "Just as consumers may home in on one aspect of the Nutrition Facts Panel because it's something that matters most to them -- they also may home in on a specific claim that is of interest to them" Wendy Reinhardt Kapsak, director of health and nutrition for the International Food Information Council, told the publication.
But getting too particular can be a problem. While consumers tend to be drawn to "structure/function" claims, they often may not see themselves as needing what the food claim offers, as when a food package claims that "calcium helps maintain bone health." Such a claim may become more valuable as the population ages and becomes more concerned about osteoporosis, but for now many younger consumers "might not see the condition as relating to them," writes Food Business News reporter Allison Sebolt.
More effective, she adds, are claims that address well-known health concerns that could effect anyone, such as "soy protein may reduce the risk of heart disease."
For food marketers, knowing all these details (as well as the regulations governing health claims, which Sebolt also examines) is crucial. But consumers might want to simply follow Pollan's core advice: "Eat food. Not too much. Mostly plants."