Obesity and Health: The roles of diet and activity

healthy food fruits and vegetables on a plate

This week’s issue of the New England Journal of Medicine blandly recounts this stunning conclusion: “By 2030 nearly 1 in 2 adults in the US will be obese, and 1 in 4 will have severe obesity”. This sounds bad, of course: who wants to be obese? Certainly not half of us.

But it’s actually far worse than it sounds because obesity brings with it profound health risks. Yan Zheng and his co-workers at the Harvard School of Public Health reported in 2017 that the risks for diabetes, high blood pressure, heart disease, and even cancer were all significantly increased by weight gain. And these increases were enormous: the absolute risk of diabetes was doubled in those who gained just 5 to 20 pounds over time.

So, weight gain is both ubiquitous and disastrous.

But is it inevitable?

We know that the average American gains about 1 pound per year after middle age, and while a pound doesn’t seem like much, over time we’re looking at 30 pounds and a health crisis for most of us. Why is this happening and what’s to be done?

It turns out that weight gain is far more complicated, and interesting, than the “a calorie is a calorie is a calorie” mantra that I was taught in medical school. Yes, weight is the balance of energy in (diet) minus energy out (activity), but what we eat, and perhaps even how we move turn out to be critically important.

Turning first to diet: Michael Pollan has thought deeply about diet, and observes: “The Masai subsist on cattle blood and meat and milk and little else. Native Americans subsist on beans and maize. And the Inuit in Greenland subsist on whale blubber and a little bit of lichen… The irony is, the one diet we have invented for ourselves — the Western diet — is the one that makes us sick.” Pollan’s sums up his solution in just three rules: 1. Eat Food 2. Not too much 3. Mostly plants. When Pollan says “food” he means stuff your grandmother would recognize as food, not the highly refined “food like substances” on offer from a food science industry that works hard to hook consumers on their junk food. We now know that simply offering people more highly refined foods result in their not only consuming more calories, but extracting more calories as well. “Not too much” is an injunction to eat when you’re hungry, and then stop eating when you’re comfortably full rather than pushing on into the “tick tight” range. And finally, “mostly plants” is critically important. Obesity is far less common among vegetarians than omnivores even when the two groups eat the same number of calories; note that one needn’t be a strict vegetarian to get most of the benefits of a plant-based diet.

In the end, the best diet is one that you can successfully follow for your entire life, and you get to choose this diet. Indeed, you do, every day.

Some researchers think diet is so important that it might allow for not just better health, but also far longer lives. If you have half an hour, have a look at Harvard researcher David Sinclair’s fascinating talk: “Why We Age and Why We Don’t Have To”.

Turning to activity: We’ve been told by the highly refined “food” lobby (Coca Cola I’m looking at you) that the problem isn’t diet, it’s lack of activity. This is a brilliant lie: by absolving their products and shifting the blame to the consumer (“if you only went to the gym every day…”) the junk food industry has a clear field to sell ever more sugar water and salty, fat laced, finger food. But this argument pushes against the stark biologic facts of metabolism: humans are immensely efficient, using scarcely any calories to do what they do. It turns out that most calories that humans burn are used just to keep their bodies turning over (circulating blood, breathing, etc.) Heck, the brain alone uses 20% of the body’s calories, and that’s when it’s sleeping. The additional calories required for physical activity are pretty modest: the body needs fewer than 100 calories to walk a mile. That’s about two miles/cookie. For comparison, if humans ran on gasoline that would be about 400 miles per gallon. So, adjusting our weight by increasing our activity seems a fool’s errand.

Briefly put: You can’t get on a treadmill and run away from this problem.

And yet. Recently a guy who sits on one of our active chairs told us that he’d lost 30 pounds over a few months by simply sitting actively. He says nothing else changed in his life: his diet, his activity, all that stuff stayed the same. True, because he’s got a desk job, he’d been sitting passively many hours a day, so simply switching to active sitting resulted in many hours of active sitting each day, but still. Perhaps more interesting, his blood pressure improved so much that he was able to stop two of his three blood pressure meds. Here’s Ken recounting his experience in 60 seconds:

Of course, Ken is what we would call an “N of 1” experiment. We have no idea if Ken is an outlier or if something other than active sitting is in play. But even if Ken is the only person who has such a profound response to active sitting it still feels great that we were able to help him make this change; helping even a single person avoid “sitting disease” and its lifelong consequences makes all the R&D time that went into developing an active chair worthwhile.

Finally, in the world of research we quote this truism: “If you throw a brick out the window, and it falls up, well, that’s interesting even if it only happens once”. We’re sending out a questionnaire to the few thousand folks who sit actively on our chairs to see if there really is something going on here. I’ll let you know what we find, but that’s for another blog post.

Reading next

four cookies shaped liked stars
hands using laptop trackpad

Leave a comment

All comments are moderated before being published.

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.