Mills, now a mother of two who lives in the UK, saw a dozen doctors and underwent over 40 procedures, including visits to endocrinologists and gastroenterologists. Several months later, she was finally diagnosed with postural orthostatic tachycardia syndrome (POTS), a disorder involving the autonomic nervous system that causes rapid heartbeat, nausea, brain fog, fainting, and fatigue.

There’s no official cure for the disorder, which primarily affects women between the ages of 15 and 50—although it has now been tied to post-COVID symptoms. At one point, Mills was on 25 medications a day. None of them worked. 

“I very much hit rock bottom, and I think it became really clear that I wasn’t doing anything to help myself either,” she says. 

Like many at a place of hopelessness, Mills turned to the internet. She read stories of countless women who have her disorder, many of whom felt desperate for any way forward and have since turned to medications and a combination of diet and other lifestyle changes. 

“I just felt I had nothing to lose but try to kind of overhaul my diet and overhaul my lifestyle, but I couldn’t cook and I didn’t like vegetables,” she tells Fortune. 

In 2012, although not a self-proclaimed unhealthy eater, Mills made a change to her diet, opting for natural ingredients and cooking at home. In a desperate plea for help and to keep herself accountable, she posted her cooking trials and tribulations on a blog. 

Over a decade later, the $20 WordPress blog account named Deliciously Ella transformed into a business that brings in $25 million in revenue yearly, with a cookbook that has sold over 1.5 million copies, and a social media following of over 4 million (a reach far surpassing other plant-based snack competitors in the field).

It has become the fastest-growing snack brand in the UK and is now expanding globally with the launch in the U.S. at Whole Foods in May of this year. In 2024, the brand was acquired by Hero Group, a Swiss manufacturer. While the company won’t disclose the deal, Mills and her husband share that “we have had numerous approaches to sell or partner with other food companies over the years, but only this one felt right.” 

The company is currently valued around $35 million, according to estimates from S&P.

“I taught myself to cook, and I did it on a blog, as I’m a very all-or-nothing person. I was like, I know I need to hold myself accountable,” she says. “It’s taken us a decade of experiments and trials and errors to get to the point where we know how to create genuinely, really good tasting products using only kitchen cupboard ingredients.”

The ‘accidental founder‘

Within two years, Mills tells Fortune her site garnered 130 million hits and reached people in about 80 countries. 

While she was still weaning off medications, Mills’s minimalist and home-cooked diet improved her illness. Two years later, she was not on any medications, and her business was growing in step.

She began posting more on social media about the recipes she was making and what she was learning. In 2014, she compiled all the recipes into an app, and in 2015, she published a cookbook that sold out before its release, instantly becoming an Amazon and New York Times bestseller. 

Mills describes herself as an “accidental founder,” who doesn’t have an entrepreneurial brain or the experience scaling a business. “I’m not trying to pretend to be what I wasn’t,” she says. It’s no surprise that she wasn’t a professional chef or nutritionist, but she marketed herself as a self-proclaimed “home cook” who wanted to—simply put—feel better. 

The beginning of the wellness craze 

A month after the cookbook’s release, Mills met her now-husband and business partner, Matt—a finance nerd at heart with the eagerness to scale a brand. Two weeks after she met him, he quit his job to work alongside her, helping her scale her business and build products that aligned with her mission. 

“He can’t cook. I can’t build an Excel spreadsheet,” she says, adding that she never wanted to license the brand to a third party to manufacture products either. “I put two really obvious skill sets together, and neither of us had any interest in the other person’s job.” 

Deliciously Ella’s first product, a cacao and almond energy ball, was released in 2016, followed by a line of other products. As of print, the brand has sold over 100 million products, and the company’s membership, available for $2.74 a month, provides access to thousands of recipes, along with meal plans and blog posts.

“It really kind of coincided with this world of wellness starting to form, and the industry taking shape, and people starting to think, ‘oh, there’s actual commercial value in this,’” she says. “I felt almost evangelical, just so passionate, about trying to get this to as many people as possible. I didn’t really care how many obstacles there were. I didn’t care about the fact that it took over my life completely.” 

Over a decade later, the importance of lifestyle changes, including diet, exercise, and sleep, in impacting both physical and mental health has become much more mainstream. 

The craze to limit ultra-processed foods has been featured in headlines, opening up a lane for brands promoting the use of minimal ingredients. Limiting ultra-processed foods has been shown to reduce the risk of chronic conditions like heart disease, diabetes, and early mortality. According to the Cleveland Clinic, diet is an integral pillar, albeit not foolproof, in treatment plans for improving those with POTS. 

And wellness and lifestyle brands have surged. Companies specializing in healthy eating, nutrition, and weight loss account for $1 trillion of the over $6 trillion wellness industry, a marketplace poised to grow to nearly $9 billion by 2028, according to the Global Wellness Institute. 

“I think you have that naive optimism when you start a business. It’s so critical because you’ve got to believe you can do the impossible. But we both just felt like, this is going to be a giant experiment,” she says. “It was like, how do we create something of meaning, of scale, that’s genuinely disruptive to the food industry, but keeping that 100% natural, and never using ultra-processed foods?”

Building a brand beyond fads 

Mills recognizes that if you don’t iterate and evolve your brand to meet the demand, you can lose relevancy. However, she didn’t want to give in to the latest wellness fads as a way to stay ahead. 

Deliciously Ella was strategically simple in scope. 

“We had a moment where turmeric was everything, where Beyonce wore a kale jumper, and the meat minute boom where the whole world was going to eat Impossible burgers,” she says. “We’re just going to stay in our lane. We’ve never jumped on any of them.” 

Mills admits there was a lot of luck to being on the lifestyle train at a time when social media wasn’t as noisy and brands were less focused on the harm of ultra-processed foods than they are today. But she credits her success to hustling to create a community of loyal followers and being consistent. 

“There are 1,000 more trends that we could jump on, but to me, that isn’t a long-term way to build the brand, or actually shift the dial on health,” she says. “If it doesn’t taste good or is way too expensive, it’s just not going to stay a part of someone’s life.”