I read an article recently that made an interesting claim: if you looked at people in the 1980s, and people now, who ate the same amount of food and exercised the same amount, the people now would still be about ten pounds heavier. The article didn’t give any particular cause for this phenomenon — instead, it left an implication hanging in the air: there is something going on. Chemicals in the food we eat? Greater use of prescription drugs, which cause weight gain? Changes in gut bacteria? The article didn’t recommend any sort of solution either, other than body positivity.
Now, I’m all for body positivity, but I don’t think tacking it on to the end of this particular article is useful. Body image is a separate issue, and one that needs to be discussed separately — mentioning it does not erase the problems with the study itself. In general, I’m extremely skeptical of articles and studies like this one. The studies tend to rely on self-reporting, which is notoriously inaccurate. And the articles don’t go into the details of whichever study they’re reporting on, so it’s difficult to judge the underlying data. If you’re curious, however, this particular study is here. It’s only accessible if you’re associated with a university or scientific body. I am, and I can tell you that the study did use “24-h dietary recall questionnaires.” I don’t know if you can recall what you ate over a 24-hour period, but I actually track calories, and unless I write what I ate down right away, I forget I ate it about half an hour later. Caloric intake was estimated based on self-reporting. Sorry, but that’s shoddy data right there. Exercise was also self-reported, based on questionnaires that assessed “if participants engaged in physical activity in the past month” (hello, can you remember your physical activity level in the past month)? But here’s the thing I really want to focus on: the physical activity assessed took place “during their leisure time.” It did include time running errands and doing yard work, which I think is good — more on that below — but it focused on leisure activities.
By the way, the study did broadly conclude that people both ate a lot more (total caloric intake rose 10-14%) and exercised more. That right there — the eating more part — can probably account for all the weight gain that the study noticed. People are heavier now because we eat more: portions and plates are both much larger than I remember in the 1980s. And various studies have shown that exercise doesn’t really help you lose weight (I know, I know, I’m skeptical about those too). Exercise keeps you fit and healthy, but weight loss seems to be largely a matter of what and how much you eat. (As well as the interplay of hormones, which is a whole other issue. No, it’s not as simple as calories in, calories out. But calories are a significant part of it.)
However, let me get to what I really want to say. What the study did not account for is the changes in how we live since the 1980s. Life is much, much easier now than it used to be. If you were around in the 1980s, you’ll remember having to dial the phone, which involved pushing buttons rather than tapping on glass. Maybe even getting up to change the television channel, or at least hunting among the various remotes. But let’s go back farther in time. Once, there were rotary phones that made dialing even harder. Once, dishes needed to be washed by hand. You used to have to walk to different stores for meat, bread, vegetables. I started thinking about this recently because I was in Eugene, Oregon, doing some research for a book I’m writing, and I stayed in an AirBnB with a microwave. It was so easy! I just put my dinner in the microwave, pushed a button, and there it was — cooked food! Granted, I did have to clean the splatters off the microwave until I figured out how to do it properly. But at home I don’t have a microwave — I have to actually cook, which at a minimum means turning on the stove and stirring. What I realized is that a microwave reduced the physical resistance involved in making dinner. Just as a computer reduces the physical resistance of typing on a typewriter. Getting a plastic bag at the grocery store reduces the physical resistance of hunting around for your bag, taking it with you, and maybe having to wash it afterward.
Technological progress has involved reducing the amount of resistance in our lives. Our lives nowadays can be so much easier than they were in the 1980s. We don’t even need to get out of the house and go to the video store . . . This has good aspects: it increases accessibility. But it also has bad aspects. If you go all the way back to the 1950s, people got a lot of exercise simply from the ordinary daily activities of living. Cleaning house took a lot more energy than it does nowadays. So did shopping. One problem with this study is that it took into account what people did in their leisure time — in other words, did you go bike riding for fun? (Which is why the inclusion of errands and yard work is a plus — those aren’t actually leisure activities.) But it did not account for the fact that our daily physical lives are so much easier. If we want to talk about weight, I think we have to take into account not exercise, but activity — overall activity, including all the things we do on a daily basis. And I suspect — no, I have not done a study to prove this, my hypothesis is based on having lived in the 1980s, but also having seen my grandmother, who lived in the 1950s, and the way she conducted her life — that even though we exercise more, we move a lot less than we used to.
I’m not a scientist, so I want to offer not a conclusion, but a suggestion. When you can, to the extent you can, take the path of most resistance. If modern technology has reduced resistance in our lives, so that we move easily (from our cars to the mall, for example), then actively seek out things that add motion to your day. Write by hand. Cook a meal. Walk to the grocery store carrying your own bag. Ride a bicycle to work. Read a physical book that forces you to flip the pages rather than just scrolling. Mail a letter (yes, with a stamp, in a mail box). Sew on a button. These are small, sometimes tiny, motions. My hypothesis is that they add up. I believe (and I have no evidence, so someone do the study please — just not with self-reported data) that adding resistance to your daily life will make you healthier both physically and psychologically. (Remember, to the extent you are able — technology has been very important for increasing access, and people should use it to whatever extent it helps them.)
I’ve tried to do this myself. I write by hand, I cook and wash the dishes, I walk to three different stores to buy my groceries. It’s a way of, not exercising, but building movement into my day. I don’t know for sure whether it makes me healthier, but it feels as though it does. And that’s my self-report . . .
I read they’ve also seen the phenomenon in laboratory mice, which are on fixed diets.
You’ll have to point me to the study, but my mother was a researcher in the 1980s, and the way laboratory animals were treated was totally different. I used to play with them at the NIH, which would never be allowed nowadays. So again, I’m skeptical. I would have to see the data.
Here’s an article that talks about it: http://www.the-scientist.com/?articles.view/articleNo/29373/title/Animals-are-getting-fatter–too/
The study is here: http://rspb.royalsocietypublishing.org/content/early/2010/11/19/rspb.2010.1890. It’s certainly important and suggestive, but it does specify that the laboratory animals studied “are typically fed ad libitum,” which means they ate as much as they wanted to. So the number of calories was not controlled over the decades studied, and we can’t draw conclusions about whether their weight gain was independent of energy consumption. I do think food composition had changed over the last thirty years, which may also be a factor — but what I’m pointing to is that we need to be careful when reading popular articles about studies like this. Often the devil is in the details. The scientists who conducted this particular study say the following:
“There are multiple conceivable explanations for these observations. Feral rats could be increasing in weight because of selective predation on smaller animals [22,23] or because just as human real wealth and food consumption have increased in the United States, rats which presumably largely feed on our refuse, may also be essentially richer. But these factors cannot account for the findings in the laboratory animals that are on highly controlled diets, which have varied minimally over the last several decades. These animals are typically fed ad libitum, so if weight increases are attributable to increases in food consumption (which is possible), it is difficult to understand why animals in controlled environments on diets of constant composition are consuming more food today than in past decades. By contrast, one could hypothesize that better veterinary or husbandry care in laboratory and companion animals and better medical care in humans could be contributing to population level increases in body weight, but this cannot explain weight increases in feral rats. Our finding of greater weight gain among laboratory animals could also be explained by changes in animal husbandry standards, such as those imposed by the Animal Welfare Act, over the past 30 years. Though it is certainly not necessary that there be a single explanation for all of these population level increases nor even a single explanation for each individual population, it is intriguing to consider whether there are any factors that could conceivably account for weight increases in all of these populations.”
That’s a very careful and sound way of analyzing this data. It is entirely possible that the presence of endocrine disruptors or other factors are having an effect. On the other hand, we also have differences in weight gain in human populations living in different places or belonging to different social classes. So whatever is happening is not affecting all populations equally, and even in this study, “results were not statistically significant in every population (11 out of 24 are statistically significant for per cent increase in weight per decade, and 7 out of 24 are statistically significant for odds of obesity).”
All that said, I still hypothesize that our level of everyday activity has changed, and that it could be a factor in weight gain.
BTW I see a problem with blaming endocrine disruptors, viruses, or changes in gut bacteria if we’re talking about lab animals like mice, because they tend to live in sterile environments. They are shielded as much as possible from viruses, and I’m not sure how lab food would change gut bacteria. They could certainly get endocrine disruptors from their plastic cages, but in that case we could study the plastic. So lab mice post an additional problem . . .
Have you noticed people are getting dumber too? This was reported by Jim Carrie and the Coen brothers.
But seriously, I enjoyed your piece.
Thank you and your blog does make sense . For me I was a big eater and ate way too much back in the 80’s and beyond. I was super overweight. These past few years I managed to fight the fat and lost a lot of weight in healthy and non healthy ways. I feel good.
Please continue to write I enjoy your work.
I love this so much! The topic of movement and activity is a frequent part of the conversations with my clients! Not so much exercise. Personally, for many folks, I think “exercise” is ridiculous. Learning to move again, walking to the stores and carrying groceries home, sweeping floors, straightening cabinets and closets, washing dishes and putting them away, playing frisbee, a walk and talk after dinner …movement. Real life day to day activity.
Have a great night. I look forward to your next post!
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You might be interested in Katy Bowman’s book Movement Matters which is on exactly this topic, and which puts in into a culture perspective as well. We all worse off because we are able to avoid moving as much in a thousand different ways (the ones you mention and many, many others).
Much of that movement is not actually avoided—rather, it is outsourced. Other people are getting repetitive stress injuries because each of them is spending 8 or 12 hours a day doing just one thing (to earn a living) so that we don’t have to spend 5 minutes doing each of 100 different things.
Considering my Fitbit just gave me 700 steps for folding laundry, I belive it. I fall into the boat of people who should probably use modern tech and take the path of least resistance more often, i.e. value my time more. I grocery shop almost daily . . . And sometimes, I really should order the part assembled instead of opting to assembly it myself.
On the other hand, I do like time-saving technology. It gives me time and freedom to do other activities. I much rather go on a bike ride, run, or walk than wash my clothes by hand.