We have long known that bacteria living on and in our bodies outnumber our cells -- which themselves sum up to a number that exceeds any hope of real understanding -- by 20 to one. We are a rounding error in our own skin.

I have long felt a nearly irresistible compulsion to write this column: an impassioned defense of the scientific method, and a denunciation of willful denial, ignorance, and hypocrisy -- and the dangers that attend upon them.

The study most recently in the headlines -- just published in the journal Atherosclerosis -- suggests not only that egg ingestion increases the risk of heart disease, but also that the association is as strong as that for cigarettes. I don't believe either is true.

Weight does not measure human worth. It is not an indicator of character. Bathroom scales are not designed to weigh merit. The boy in the Nike ad may well be full to the brim with greatness -- but none of it has anything to do with running.

Several years after making headlines for its health care reform, Massachusetts is back in the news, this time for passing legislation that aims to impose a cap on overall health care spending. That ambition implies, even if it doesn't quite manage to say, a very provocative word: rationing.

Taste buds can be rehabilitated. They are, in fact, very malleable little fellas: When they can't be with a food they love, they can quite readily learn to love the food they're with.

The way we respond to obesity and related chronic disease in the U.S. is like waiting to send every adult to night school to learn English -- painfully, poorly, expensively, and late -- rather than having them grow up speaking fluently all along.

If just standing more and sitting less can add years to life and life to years, then we owe a lot of ill health to the seats of our pants. The solution is for us each to incorporate strategies into our daily routines that allow us to get up and move about -- at least a little, at least intermittently.

Our popular culture acts as if it would make sense to optimize one wing of a plane. The plane is either fit to fly -- or not. You can't fly half a plane. Selectively cultivating the health of favored organs or body parts is a comparable flight of fancy.

The updated advice from the Preventive Services Task Force about obesity screening harbors good, bad, and a bit of the downright silly.

The best defenses of the human body reside largely, and often inextricably, with the body politic. Public health is for the public -- and is best advanced by the collective efforts of the public.

I was privileged and honored to deliver the keynote address recently at a local high school graduation. My marching orders were to deliver a generally inspiring exhortation on being selfless and giving back in seven minutes or less.

The lore and the legend of the horse whisperer honors a whisper heard, not spoken. That all of us could learn to hear and understand horses better might matter to some more than others. That we might all learn to hear and understand one another better matters to us all.

We can make health a prevailing cultural meme by replacing our unconscious adaptations with conscious choices. It's true, we are adapted to like sweet. But we are also adapted to be terrestrial -- yet can learn to swim, and to hold our breath under water.

Excess dietary sugar is harmful, and among the salient liabilities of the modern food supply. Sugar is not poison, however. And yes, I think the distinction matters enough to keep fighting for it. Here's why.

We are, no doubt, all familiar with the expression "you are what you eat," but given how most of us eat, it's quite clear we don't take it very seriously.

The USPSTF has moved on from ambivalence about prostate cancer screening with the PSA test, and inveighed decisively against it -- a recommendation that is apt to stoke the flames of competing passions, and generate a whole lot of heat but altogether too little light.

There is an intrinsic problem with measuring the quality of a system by how well it conforms to what you already believe. Such a system gets bonus points for agreeing with you -- even when you are wrong.

Fundamentally, we have converted a world in which calories were relatively scarce and hard to get and physical activity unavoidable into a world where physical activity is scarce and hard to get and calories are unavoidable.

The National Consumers League, claiming to represent consumers' interests, issued a press release this week announcing they had submitted a complaint to the FDA, asking the agency to banish NuVal from the nation's supermarkets.

When it comes to nutrition and the monumental influence it has on our health, the rubber hits the road wherever people and food come together. Kitchens and cafeterias. Schools and workplaces. Supermarkets and restaurants.

If we are prepared to acknowledge the widespread bullying to which both science and sense are subject at the hands of the almighty dollar, we might commit ourselves to the systematic effort of distinguishing the two.

The wellbeing of children is everybody's business, and everybody should mind that children are staring down the barrel of a glow-in-the-dark cheese doodle or sugar-laden cereal loop at foreshadowed health and foreshortened lives.