Here with a blog item to read as you digest your lunch -- a bacon cheeseburger with an egg on top, with jumbo side orders of onion rings, Hollandaise-covered asparagus (gotta have a healthy vegetable!) and chocolate lava cake a la mode. 

The story of the day is Peter Whoriskey's meticulously reported tale of whole milk -- demonized for decades, accused of harboring killer fats, but on closer analysis not actually bad for us. In fact, studies suggest that people who drink whole milk appear to have lower rates of heart disease than people who drink low-fat or skim milk. This appears to be another reminder that nutrition, and biology more generally, is much more complicated than we'd like to think.

The slur on whole milk came from logical thinking. Whole milk is loaded with saturated fats. Saturated fats increase "bad" cholesterol. The bad cholesterol can contribute to heart disease. Thus you should avoid whole milk, right?

The problem is, many people who avoid whole milk replace those saturated fats with carbohydrates -- and junk food. Except, as Whoriskey reports, saturated fats can also boost "good" cholesterol, which can protect against heart disease.

At one point, the United States government considered butter a food group. Here's some other dietary advice that no longer holds true. (Jayne W. Orenstein/The Washington Post)

This story serves as an indictment of "nutritionism," the belief that a good diet merely requires that we avoid a few potholes on the road to satiation. [Mental note: "The Road to Satiation" would be a good title for a memoir.]

Probably the most articulate and persuasive writer on the dangers of nutritionism is Michael Pollan ("The Omnivore's Dilemma," and many other books). For years, Pollan has argued that you should eat the kind of food that your grandmother would recognize. That probably includes eggs and whole milk -- but not Twinkies.

We e-mailed Pollan for comment on the possible rehabilitation of whole milk.

Pollan tells us:

I've long felt that skim milk was silly. Think about what it means to remove fat from milk: you end up with a more sugary beverage, since the amount of lactose per ounce rises. And we're learning that sugar is probably a more serious nutritional problem than fat. Then think about what happens to the fat that was removed from all that skim milk.  It is turned into cheese and sold back to us as pizza. As we consumed less butterfat in milk, we consume more of it as cheese, so in addition to fooling ourselves in thinking we were cutting down on fat, in the end we paid twice for the same fat! It's a bit like refined white flour. So I've been drinking whole milk for a long time and, if you haven't tasted it in a few decades, it is delicious. You also drink less of it since it is more filling. Last point to consider: some kinds of skim milk add powdered milk to improve the body of that watery, tasteless swill, and whatever you think of milk powder -- some people think it's not good for you -- you're ending up with a processed food, rather than the sort of simple food your grandmother would recognize.

We asked him to elaborate on his famous instruction to "eat food, not too much, mostly plants." He writes:

Eat food. Not too much. Mostly plants. All you need to know. Yes, we constantly divide the nutritional landscape into good and evil nutrients. There are several problems with this manichaen approach to food, but one is that, as soon as you demonize one nutrient -- say, fat -- you give a free pass to another, supposedly less-evil nutrient -- carbs. What I call the Snackwell's phenomenon, after that Nabisco line of no-fat junk food in the 1980s. Since these cookies, crackers and chips didn't contain any of the evil nutrients, people felt they could binge on them. This is story of the low-fat campaign writ small: consumption of fat in absolute terms remained steady while consumption of supposedly innocent carbs skyrocketed. Nutritionism is a great way to sell food, since you can market the absence of evil nutrients or the presence of blessed ones, but its not a good way to eat. Which is why we got fat during the years of the low-fat campaign.

A final thought: There is 10 times as much non-human as human DNA in our bodies. We contain trillions of microbes. We are composite organisms. How this system works is not simple. We should be intellectually humble about what we know and don't know about our own biology. Already in recent years the biologists have come to realize that the decoding of the human genome isn't going to explain as much as they had hoped. That's why there's so much interest in epigenetics.

Apparently we're still a long way from The End of Science.

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