A dramatic shift in how Americans think is killing the diet industry

Not too long ago, thin was in.

Women across America popped Lean Cuisines into their microwaves, subscribed to Weight Watchers, and wiped beads of sweat off of their headbands mid-aerobics class, worrying that their bodies weren't good enough as they were.

Now it's 2016, and that Lean Cuisine meal is an avocado, Weight Watchers is Whole 30, and that aerobics class is SoulCycle or barre - and plenty of women are content with their shapes.

That shift is killing the diet industry.

For so many years, the diet industry has played on women's - and men's - vulnerabilities. But now that women are becoming comfortable as they are and beckoning to retailers to represent them accurately, they no longer feel the need to starve themselves. They simply wish to take care of themselves and feed their bodies good, natural foods.

A recent NPR piece highlighted these trends, which are worrisome for the diet business. First, the story pointed out, people are more into health than dieting. This is one of the reasons Weight Watchers could continue to struggle, amid bringing Oprah on board. NPR pointed out that Lean Cuisine sales dipped 15% between summer 2014 and 2015, too.

Dieting is taboo; loving yourself is in.

"Dieting is not a fashionable word these days," Tufts University nutrition and psychiatry professor Susan Roberts said to NPR. "Consumers equate the word diet with deprivation, and they know deprivation doesn't work."

"Consumers are not dieting in the traditional sense anymore - being on programs or buying foods specific to programs," Mintel analyst Marissa Gilbert said to NPR. "And there's greater societal acceptance of different body sizes."

It's likely that young women, the most vulnerable and impressionable consumers of all, just aren't buying into what their parents might have bought into.

Companies like Aerie, with their unairbrushed "Aerie Real" campaign, have shown women that they are beautiful as they year, without Photoshopping, and regardless of their size. Its most recent campaign with plus size model Barbie Ferreira highlighted this.

These campaigns are resonating so strongly with women that the company's sales are exploding. In its most recent quarter, sales skyrocketed to 21%, and CEO Jay Schottenstein admitted in an earnings call that he believes sales will double over the next few years.

Women have retaliated against companies like Victoria's Secret who seem to impose that beauty has one size. The company's "Perfect Body" campaign landed with a thud and sparked outrage. Consumers have demanded that the brand start selling larger sizes and plus size model Brittany Cordts petitioned for the brand to showcase fuller-bodied models.

Plus size models, in general, have garnered more attention, too.

It goes beyond the retail sphere, too.

When Protein World released a campaign asking New Yorkers if they were "Beach Body Ready," people responded furiously. They already had beach bodies, thank you very much, they just had to go to the beach in their corporeal forms.

And Mattel recently released a curvy Barbie doll, as though finally admitting that women with hips can be beautiful, too.

(And then, of course, there's DadBod, last year's celebration of the chubby male with his newly minted beer belly.)

It's clear that people are feeling better about their own set of genetics and society is embracing that. That doesn't mean people are treating their bodies poorly; there's a shift towards moderation rather than deprivation, and an even greater shift towards wellness.

Plus size model Ashley Graham told Business Insider that she eats healthy and works out, she's just not a toothpick. 

"I want more definition like in my thighs and stuff, so you know I have body goals for myself as well, but I'm not trying to lose inches. I'm just trying to keep toned," she said to Business Insider in a phone interview this summer.

"You can be healthy at every size," she said at the time. "As long as you're getting off the couch and doing something."