The Surprising Truth About What’s Really Making America Fat

We’ve been told that the world is getting fat because we’re all eating too much, but new research says that for America at least this isn’t true: it’s our lack of exercise that is probably to blame.

Publishing this month in The American Journal of Medicine, researchers from Stanford University in California, provide us with a new analysis of the National Health and Nutrition Examination Survey (NHANES), a program of studies that aim to assess the health and nutritional profile of adults and children throughout the United States by combining personal interviews and physical examinations.

In particular, the researchers wanted to see how rising rates of obesity, and what’s known as abdominal obesity, showed up in the data and what their strongest associations were: diet or exercise.

To investigate this the researchers looked at data in the NHANES that tracked diagnosed obesity, abdominal obesity, reported physical activity, and reported caloric intake in adults in the U.S. taken from 1988 to 2010. What they found is that levels of exercise have dramatically decreased, something that appears to be contributing to the rise in obesity.

For instance, the number of women who said they took no physical exercise during the study period went from 19.1 percent in 1994 to 51.7 percent in 2010. The figure for men isn’t much better, going from 11.4 percent to 43.5 percent.

Unsurprisingly, the average Body Mass Index rating (BMI) increased across every age group, but the most dramatic rise was found among young women between 18-39.

The researchers then looked at food intake. While the researchers didn’t dig down into what kinds of food are being consumed, the data actually shows that the overall daily calorie intake and levels of fat, carbohydrate and protein that are being consumed hasn’t changed significantly over the last twenty years.

This is very interesting as we are often led to believe that people in the West are simply consuming more food and that this is the key factor in obesity rates, but it appears that this isn’t true–it’s our sedentary lifestyles that are really driving up our BMIs.

“These changes have occurred in the context of substantial increases in the proportion of adults reporting no leisure-time physical activity, but in the absence of any significant population-level changes in average daily caloric intake,” says Uri Ladabaum, lead researcher and associate professor of medicine at Stanford University’s School of Medicine. ”At the population level, we found a significant association between the level of leisure-time physical activity, but not daily caloric intake, and the increases in both BMI and waist circumference.”

What’s the reason for the drop-off in activity rates? It’s probably not just that we’re getting lazier, but more to do with that we’re working more which leaves little time for exercise. That’s something that future research will have to explore.

Now it’s important to stress that BMI is not always an accurate predictor of health, which is something that the researchers have noted. However, as a guideline this research provides an interesting insight, especially in how it appears that physical activity and a lack thereof is what really might be driving the so-called obesity epidemic.

That said, we know that exercise alone doesn’t yield the kind of weight management results that exercise teamed with a healthy diet can bring. We also have plenty of research that says a diet rich in legumes and other vegetables is important for supporting overall body health and a strong nutritional profile that keeps the body working at its best. This study does not change that, but it does suggest that in the national battle against the bulge we might wish to switch some of our focus from what we’re all eating to how much we’re moving.

If you find it hard to fit in exercise in your very busy schedule, you might consider how to incorporate exercise into your daily routine. There’s the obvious, like taking the stairs instead of the elevator and walking rather than using the car whenever possible. If you’re stuck at the office though, you might also consider taking a look at how circumspect exercises using your office environment can help you stay healthy while on the job. It’s not a replacement for dedicated and regular exercise, but if you’re working late it can be a good temporary fix.

Photo credit: Thinkstock.


Roberto Meritoni
Roberto Meritoni1 years ago


Roberto Meritoni
Roberto Meritoni1 years ago


marie moran
.2 years ago

Enough of the excuses, individuals are responsible for their own health.

Haleigh O.
Haleigh O.2 years ago

It's also the fact that we eat processed food. Chemicals + no exercise is not going to make anyone healthy. We all need to mind what we buy at the grocer and stop funding GMO and chemically indulgent food.

Winn Adams
Winn Adams2 years ago


jelena skipina
Past Member 2 years ago


Julia H.
Past Member 2 years ago

Paul C.

Seriously? Who the heck cares what a person wears while working out, biking, walking, etc. I could care less of someone does not like what I am wearing while biking and walking. Give me a break. That is the worst excuse I have ever heard.

Nothing like being a slave to others opinions.

Mac C.
mac C.2 years ago

Steve, I like your idea of getting some exercise as you go about your daily routine. Everyday I try to get a good walk and some weights in-- not always successful-- but I do stay active throughout my day always. I work from home, so I find taking little breaks from my desk to make everyday activities become small exercise opportunities-- like gardening, cutting the grass, cleaning, a few Yoga poses here and there, walking to some places I need to go, taking the stairs (I'm lucky to have stairs in my home and I go up and down them as much as possible). Thanks for post.

A F.
Athena F.2 years ago

Not surprising at all. We're all here on the internet now, right? Unless some of us are able to type and jog at the same time.. ;)

Our society revolves around desk jobs, computers, sitting. It's gonna bite us in the boo-boo.

It's also the crap they put in most of the food now too. Everything is so hyper-sweet with the varying concentrated sweeteners. Even the "sugar-free" "calorie-free" ones are so incredibly sweet, they trick your brain into thinking you just ingested way too much sugar. It responds appropriately, and this can also cause issues with metabolism, etc.

Francesca A-S
Past Member 2 years ago

Thanks for sharing