Wilson and former colleague Zoe Eaton self-funded and founded I Quit Sugar.com.

Wilson started experimenting and ultimately changing her own diet after she was diagnosed with Hashimoto's Disease in 2008. She began blogging about her new sugar-free life and found a huge following of readers keen to learn more about the health benefits of culling the natural sweetener from their diets.

This led to the digital I Quit Sugar Cookbook, which was picked up by Pan MacMillan and published in 43 countries. A sequel, I Quit Sugar for Life followed.

"We realised there was an enormous appetite for thoroughly researched information on the sugar-free diet and its health benefits," says Eaton, general manager of the Sydney-based company.

IQS.com runs three eight-week diet programs every year. Participants pay $150 and get access to dietitians, 25 specialists and Wilson's tranche of recipes.

"Because when you quit sugar you basically quit processed food and so you really have to re-learn how to cook."

The fruits of their labour have been sweet. In its first year IQS.com turned over $534,000. In 2014-2015 it will pass $4 million.

About 60 per cent of revenue comes from its diet programs, 30 per cent from its digital cookbooks – 10 and counting – and the rest from advertising. IQS draws one million social media followers and three million views per month.

"Our primary revenue is from the program ... the advertising revenue, while we don't rely on it, is also a very important channel to have and produces really beautiful integrated sponsored content, which is quite often our most read content every month.

"We are in a nice place with that side of our business; we can pick and choose who we want to work with at the moment."

Asked about competitors, Eaton says: "There is no-one else really doing what we do."

"You've got (The Biggest Loser co-host and personal trainer) Michelle Bridges in the fitness market and Kayla Itsines from Adelaide, but nobody else like us."

MySmallBusiness tried to contact both Bridges and Itsines (who sells 'Bikini Body Training' courses) to discuss their e-business models, plans, industry challenges and advice for others considering entering the online fitness/health sector? Both fitness personalities offer 12-week online fitness programs. Both declined an interview.

"We do not disclose any of this information to third parties as we are a privately, held company in a very competitive category," replied Sue Klose, chief operating officer of Bridges' 12WBT.com site, via email.

Itsines was unavailable due to other commitments and an "extremely busy schedule in the lead up to her World Tour in June", a company spokeswoman relayed.

Fortunately Melbourne e-health business owner Sita Huber is available. She founded Mind Body IQ, a platform for sharing and promoting expert advice on health and wellbeing this year, is a qualified nutritionist and has worked in sales, distribution, social media and strategy in the health, diet and fitness sectors for more than a decade.

According to Huber the weight loss market, in particular, faces unique challenges due to new buying platforms, increased consumer literacy, and preferences for DIY products and services.

"Consumers have become much more wary of marketing tactics aimed at weight loss and seek more personalised approaches that impact lifestyle," she says.

"As such, we are seeing a boom in the e-fitness industry as customers move from diet products to diet services, right from the comfort of their own home. Consumer awareness is growing as people are looking to be active participants, and 'take control' of their own health."

Market trends will concern some health professionals who may be worried that by clicking to get a fitness and/or diet program some consumers will become isolated.

"If you are a new entrant to e-diet or e-fitness you'll need to own your online niche, engage your target consumers and build trust to achieve brand longevity in a highly volatile space.

"There is inherent value in physical presence and observation in person (but) the market is dictating a new direction, so we must respond and do our best to humanise the process; look at layering service platforms, creating content, and speaking to the lifestyle of your customer."

Scott Hunt is CEO of Fitness Enhancement. He started his business in 1999 with $400. Today his company operates nationally and annually turns over more than $2 million.

Hunt's chief concern with the current boom in e-fitness and e-diet businesses is the industry is unregulated, although he says some human "virtual" personal trainers can create personalised diet and exercise programs and regular online follow-ups that help clients who can't or won't meet a PT in person.

"It's partially boomed thanks to technology and the power of the internet being able to make somewhat personalised online programs," Hunt says.

"The problem is that's rarely good enough to give people what they need and unfortunately people tend to treat what 'Dr Google' says as fact, especially if being said by someone with a big name, or good abs."