Xin Wang, an epidemiology research investigator at the University of Michigan, has discovered the real reason Americans are increasing in girth: air pollution.

You see, back in the 1940s, 50’s, 60s, and 70s when Americans were thinner there was no air pollution to make us fat. Then the Clean Air Act was passed and the EPA started cracking down and our BMIs skyrocketed due to the increased air pollution.

Looks like all that water weight might actually be from the air.

A new study suggests that long-term air pollution exposure is linked to women gaining weight — particularly ladies in their late 40s and 50s, EurekAlert reported.

Observed women who were exposed to poor air quality, specifically higher levels of fine particles, such as nitrogen dioxide and ozone, had seen increases in their body size, according to study author Xin Wang, an epidemiology research investigator at the University of Michigan.

The exposure to air pollution was tied to higher body fat, fat proportion and lower lean mass for middle-aged women. EurekAlert noted that “body fat increased by 4.5%, or about 2.6 pounds.”

The data came from a mix of 1,654 white, black, Chinese and Japanese women whose median age was 50. They had been tracked for eight years from 2000 to 2008.

This is what we call in the writing biz “complete bunk.” You could also call it “junk science.”

How do I know it is junk, other than the obvious? Because if weight gain was caused by air pollution, we shouldn’t be so much fatter than people who lived a few decades ago when much less was done to increase air quality. In fact, when pollution was at its worst Americans in general were much fitter.

When the air was super clean in the 1950s a typical beach scene looked like this:

The 1960s, the height of clean, breathable air produced scenes such as this:

But today, when pollution is destroying our lungs things have gotten so out of control that you could typically find scenes reminiscent of Wall-E:

Look, we all know why Westerners are getting fatter on average than in earlier times: our diets suck and we don’t exercise enough. Processed foods are unhealthy, the government gave us horrible advice about avoiding fat and downing the carbs, and we spend way too much time mesmerized by screens.

Amid the sea of fat people–of which I am one, by the way–there is a large number of incredibly fit Americans. Young, middle-aged, older. They move. They eat better than we do. They take care of themselves. And they look great, too. I wish I were one of them, but I am lazy and eat too much for my own good.

I love science and scientists, but there is an awful lot of junk science out there. Most nutrition science over the years has been total junk, and we all would have been better off if the nutritionists and government advisory boards over the years had just shut the hell up. Said nothing. No advice. Stay in cubicles or whatever. Their advice has sucked, although I hope and suspect they have learned over the years.

When I was young my family visited a nutritionist in the 1970s. We were advised to eat more bread, substitute margarine for butter, and keep the protein down. Horrible, horrible advice. The only good advice was to eat more vegetables, which none of us did. But we sure ate a lot of bread with margarine.

So my advice? Quit listening to advice, buy the Julia Child cookbook or something similar, and get out and move.

But then again, I should take my own advice and just shut up about nutrition. I don’t know much either.