I can’t remember the last time I was so annoyed reading an article as “How Junk Food Can End Obesity” by David Freedman, which I believe was the cover story of The Atlantic’s July/August issue. Don’t read it (I know, you probably weren’t going to read it at this point anyway, I’m a bit behind the curve). It’s 10000 words of mostly anecdotes and poor logic. Now that I think about it, I can remember the last time I was so annoyed by an article: when I wrote my first-ever blog post in response to some eugenics garbage back in May.
Anyway I came across this Atlantic article when Steven Pinker posted the following on twitter in late September: “@sapinker The 1st article on food & obesity I’ve read in years that makes sense – forget Bittman & Pollan.” I honestly know very little about Dr. Pinker and actually appreciate his oft-inflammatory links but couldn’t get over the inanity in this article. Yes, to some degree it’s foodie-baiting. And after reading it and seeing that dozens of people/internet-news-types have already critiqued the piece Mr. Freedman probably got what he wanted. That said, I think there’s some interesting science to talk about here that disputes much of this article’s ‘logic’ and might make you a little more aware of what we can say about food, nutrition and obesity.
To begin, I’ll mention that Mr. Freedman does get one thing correct: there’s nothing inherently wrong with ‘processing’. Just like there’s nothing inherently wrong with “GMOs” or “drugs” or “chemicals”. Each can be bad or good depending on the circumstances and use. Labeling foods as bad because of semantics on what is ‘processed’ or ‘natural’ is indeed a poor way to go about nutrition. And Mr. Freedman goes on for a while with some anecdotal stories about how this ‘natural’ food isn’t as healthy as you might think and this ‘real’ food is just as bad for you as a processed food. This is hardly a new idea but I agree with his tenet in this case.
What Mr. Freedman gets wrong is his assumptions the rest of the article are based upon. He takes certain facts for granted largely because they’re the status quo, and NOT because they’ve been unequivocally shown to be true by science. Science is hard, and what I’ve come to find out is nutrition science is EXTRA hard. There are a lot of reasons for this, but suffice it to say that different goals for different people with different genetics and different environments at different ages creates a ton of noise in any studies on what’s good for us. In short: humans are complicated organisms.
I find Mr. Freedman’s reliance on the status quo as extra ironic because he’s written a book called “Wrong: Why Experts Keep Failing Us—And How to Know When Not to Trust Them.” Daniel Engber at wrote about this at Slate and it appears he’s actually read the book so his word is better than mine, but in short Mr. Freedman’s inability to recognize how few objective truths we have when it comes to science on obesity is nothing short of hypocritical considering he wrote a book on how wrong ‘experts’ often are.
This is most apparent from Mr. Freedman’s continued use of the word ‘obesogenic’ throughout the article. 10 times, in fact. Well, here’s some not-all-that-surprising-considering-the-obesity-epidemic news for everyone: we don’t know what makes people fat! Some people think it’s sugar. For decades government ‘experts’ agreed it was because we were eating too much fat (more on this oversimplification later). David Berreby wrote a fascinating article about our animal roots and obesity that gets at a lot of the science behind our fatness, but he concludes by saying that the answer’s not that easy: obesity probably has dozens of causes that run the gamut from our evolutionary propensity for a quick calorie fix to hormone-imitating chemicals to microorganisms. Now THAT is a good, well-researched article.
Here’s one particular assumption being made by Mr. Freedman that blows a hole right through his basic premise. IT’S NOT ALL ABOUT CALORIES IN/CALORIES OUT. This seems logical and everything, so much so that my college biology teacher (who, ironically, was fat) was spouting it to hundreds of us naïve ankle-biters, but it is extremely misleading. Yes, in terms of ‘thermodynamics’, eating too many calories will make you fat. But food isn’t just calories. Food is varied and sets off feedback mechanisms and hormonal responses that can make you want to eat more or less food depending on what you’ve eaten already, the context of when/where you’re eating it and if YOU’RE eating it (i.e., people respond differently due to their own genes, microbiota and environments). To quote that superb David Berreby article, “Chemicals [with hormonal properties] ingested on Tuesday might promote more fat retention on Wednesday.”
For example, Mr. Freedman goes on at length about how we need to work with Big Food companies because they can trick us into eating lower calorie foods that taste as good or satisfy us just as much. Well, the problem is: the calories themselves are a major factor in being satisfied. One cool 2008 study in particular used mice that had their taste receptors for sugar knocked out (knockout mice have their genes modified such that selected traits can be eliminated) and had them choose between either sugar water or water. At first, the mice didn’t care which they drank from, since they couldn’t taste the sugar. However, over time they found the mice would drink significantly more from the sugar water. This means their bodies actually could ‘sense’ the calories and send a message back to the brain saying ‘dude, drink THAT one’. From an evolutionary perspective this makes total sense: your taste buds probably don’t know what nutrients you’re lacking but your body does. While they’re tuned to more immediate problems like ‘is this poison?’ or ‘these berries aren’t as sweet as THOSE berries’ that you need to act on immediately, what your body actually cares about is essential nutrients like calories (or protein, as shown in a later study). As a result, when you’re drinking non-caloric diet soda with sugar substitutes that are hundreds of times more sweet than sugar, they might satisfy you for a bit but you’re hardly fooling your body into being less hungry. Which helps explain why regular consumers of diet drinks are actually fatter than non-drinkers. Edit: there’s also a new study directly linking the consumption of artificial sweeteners to obesity/diabetes.
There’s even more to it than that, since those taste receptors do report on how sweet that diet soda is, and there are feedback mechanisms that alter how you take in future calories. A 2013 Journal of Neuroscience paper found that rats given a 3% saccharin solution for 7 days had similar brain changes (specifically, trafficking of AMPA postsynaptic receptors in the nucleus accumbens—sort of like your brain’s pleasure center) to rats given a 25% solution of sucrose for 7 days. This means those obesogenic effects (notice how when I use the term there is actually a study behind it) from diet soda could very well be a direct result of your brain thinking there are way more calories coming in than it actually gets.
Something else that annoyed me even more about Mr. Freedman’s article was his later retort to the many, many articles telling him how wrong he was. While arguing on the internet is hardly productive anyway, his responses further show how little he really knows about modern thinking on nutrition. In particular, here is what he said to a nice response piece from Tom Philpott at Mother Jones:
It was really sad to see this piece. If any publication should have empathy for the plight of the unhealthy poor, you’d think it would be Mother Jones. But no, this was just a dopey, rote screed by an Atkinite, that small but incredibly loud cult of ultra-low-carbers who have become the LaRouchians of the dietary world. Calories don’t matter! Exercise doesn’t help! Eat all the fatty foods you want! It’s all about the carbs! The Atkinites like to claim that everyone else is stuck in the “low-fat craze” of the 1980s. They don’t like to mention that the low-carb craze dates to the 1860s. For the record: It’s best to trim both carbs and fat. Ask your doctor, or any obesity expert.
NO NO NO NO NO. Tom Philpott says nothing about the Atkins diet. Instead, he points out REAL, MODERN research that shows how little eating fat correlates with being fat (this might turn out to be English’s most costly homonym). There is a wealth of modern evidence indicating that low carb diets work quite well (point 10 here has a nice, quick compilation of evidence from the last 10 years, while I can give you days of additional reading material. I recently enjoyed Denise Minger’s exhaustive takedown of Forks over Knives, for one). Meanwhile, Mr. Freedman thinks we should just ask our doctor. Ugh. Is he trolling us at this point? As an expert on experts you’d think he would be aware how little ‘your doctor’ knows about nutrition. Or most things for that matter—that’s what specialists are for.
In fact the more I read the article the more it just seemed like a giant, thickly-veiled troll. For example:
I finally hit the sweet spot just a few weeks later, in Chicago, with a delicious blueberry-pomegranate smoothie that rang in at a relatively modest 220 calories. It cost $3 and took only seconds to make. Best of all, I’ll be able to get this concoction just about anywhere. Thanks, McDonald’s! If only the McDonald’s smoothie weren’t, unlike the first two, so fattening and unhealthy. Or at least that’s what the most-prominent voices in our food culture today would have you believe.
You’re drinking a cup of sugar water. Maybe it has some remnant of fruit in it, but honestly I wouldn’t suggest eating non-organic berries anyway. And I’m sure Mr. Freedman knows it’s sugar water. If he’s trying to claim that sugar water in smoothie form should cost $3 instead of $8 that’s fine by me. But when he’s trying to act like fast food enterprises have anything but profits in mind he’s quite mistaken. As I’ve mentioned above, your body is designed to detect calories, and if these companies don’t know this scientifically they know it from their profit margins. McDonald’s smoothies are a perfect example of this, in fact. Only 220 calories! Which means you’ll need to eat a bunch more of their food to feel full. And since it’s sugar, it’ll probably just make you more hungry anyway. But since it has the words ‘blueberry’, ‘pomegranate’ and ‘smoothie’ it hides under the guise of healthy. And I know HE knows this, so his point is completely moot. Maybe he was getting paid by the word?
I suppose that’s enough vitriol for now. I suggest a few blogs below who cite legitimate scientific studies and use their expertise to critique the modern literature. It’s not easy reading though, and as I said earlier with how complicated nutrition is the findings are often quite incremental. That said, modern techniques are starting to uncover some fascinating pieces here and there (e.g. here’s a great study on a direct link between eating red meat and accelerating heart disease), and unlike Mr. Freedman will have you believe, we’re making progress without having to resort to tricking ourselves into thinking we can trick our bodies into becoming thinner.
Stephan Guyenet’s site is a good source of well-referenced, science-based info.
Mark’s Daily Apple looks kind of ridiculous because the site is littered with pictures of him with his shirt off (my friends and I like to refer to it as Mark’s Daily Ab-shot) but the info is pretty legit and usually well-referenced.