Among the more noteworthy of recent news where diet, health, and business converge is the large investment by Campbell Soup in a start-up food company promising customized nutrition. The company, called Habit, has garnered not only Campbell’s sizable cash infusion (over $30 million), but also widespread media attention in response to its claim that dietary prescriptions for weight loss and health promotion can be personalized based on cutting edge science. The company’s founder and CEO has been quoted as saying it is “just common sense to reject the idea that we all need the same food.”
With all due respect to the promise in these promises, and there genuinely may be some, neither science nor sense provides an unqualified endorsement.
Let’s start with sense, since an appreciation for it, if not its application, is the more common. What does sense say about dietary customization?
Looking at the world from just a bit of altitude, sense seems to suggest that creatures of the same species do, indeed, need substantially the same food. Zookeepers, for instance, rely almost entirely on sense to feed their diverse charges. Sense, not randomized trials, tells zookeepers, and the rest of us for that matter, that the lions are apt to do well with some kind of meat, the sea lions should get fish, and the koalas will manage as only koalas can on eucalyptus leaves.
No doubt, there is metabolic and genetic diversity among individual lions of land and sea, as well as koalas, to say nothing of gibbons, tapirs, and iguanas. But when it comes time to feed these or any other creatures in our care, we look right past those minor differences and feed them the fare that suits the species. Common sense, it seems, argues after all for feeding much the same food to the same kind of animal.
That just leaves one challenge to sense: are humans fundamentally different? Do our individual differences, in a departure from all the rest of biology, matter more than our phylogenetic family ties?
To the best of my knowledge, the answer is a resounding “no.” We are an extraordinarily adaptive species, and by dispersing to the far reaches of the planet and adapting, in some cases over generations, centuries, and perhaps even millennia to diverse circumstances, we certainly demonstrate true biologic distinctions. Some of us, for instance, are constitutionally intolerant of lactose because we stop making the enzyme that digests it in infancy. Others of us, with ancestors who faced a “digest dairy or die” dilemma, are beneficiaries of the genetic response of the survivors, and remain capable of breaking down lactose throughout life. There are many other such examples, some of which are just now coming to our attention.
But this human distinction is clearly one of degree, not kind, and modest degree at that. We are a species. The fundamentals of the dietary pattern to which we are adapted, and on which we thrive, are indeed common to us all. There are, to be sure, variations on the theme of feeding Homo sapiens well- but the theme is the stuff of massively convergent evidence from diverse populations around the globe, and simply isn’t negotiable.