NECESSITY is the mother of invention, so the saying goes. And so it has proved for Bradford entrepreneur Farnaz Khan.

The desire to reduce post-pregnancy weight gain after trying diets, exercise and diet pills led Farnaz, already a successful online marketing businesswoman, to develop another means of shedding the pounds.

The answer? Heat emitting knickers made from a special knitted fabric using advanced technology which are sold online to women in 50 countries through Fit Britches, her new business which launched at the beginning of this year.

The 34 year-old Bradford-born mother of four originally came up with the concept of using heat to achieve targeted weight loss after researching the internet. But her early trials were far from sophisticated.

"I started by wrapping myself in cling film and wearing big knickers. The final straw was when my mother asked me why my dress was making strange noises and I realised i needed a better solution," said Farnaz at her City Hub base in Little Germany.

She was determined to pursue her findings of a strong synergy between heat and weight loss.

Farnaz recalled: "My research indicated that raising the core body temperature stimulates the metabolism , increases blood flow and reduces fat . Looking for a more discreet option than cling film I found there was not much available so set about developing a product which has involved four or five years of working with people in textiles technology in the UK and around the world.

"I eventually developed a prototype product which enabled me to go down from sized 14 to size eight."

Her belief ion the concept of using heat to aid weight loss was confirmed by independent research she commissioned among a group of women aged between 20 and 60 which resulted in 92 per cent seeing increased blood flow , an 11 per cent reduction in cellulite levels and an average weight loss of between five and eight centimetres on the waist.hips and thighs.

Her own significant weight loss caught the attention of friends and family - which sparked the idea of a commercial venture.

Farnaz was worried whether the products would sell following the recent recession and during a time of austerity but to her relief has found that women remain willing to spend on themselves and their image.

Soon after its launch Fit Britches knickers were featured as a 'top pick' on ITV's Good Morning programme and this has been followed by widespread national and regional press coverage and global internet mentions.

"We started with one size in one colour but now have a range of sizes and colours, with product development driven by consumer demand. The TV plug was a major boost and caused us growing pains as stocks ran out. But, rather than cancel,many customers were willing to wait for new stock. I have focused on clearing the backlog and am now concentrating on expanding the product range, including active wear for men who are showing increasing interest in what we're doing, "she said Farnaz said the Fit Britches enterprise would enable her to combine her technology-led marketing expertise with a family textile heritage - her mother and sister are in the rag trade - as was her grandmother.

She also has the ambition to transfer Fit Britches development and production - currently in Italy - to the Bradford area at some stage and is on the lookout for suitable premises.

She sees the potential for helping tor revive the textile sector locally as well as tackle the decline in traditional skills - something on which Farnaz has become a vocal campaigner.

"I'm talking to Bradford Council and other bodies about what we can do to support the textile trade and develop skills . I want to build up a seamless manufacturing and technological process for Fit Britches here but need to be sure that we have the specialist dyeing and fabric knitting capability on which we can build.

"Skills remains the key issue, however, We still have people with the right experience and expertise but many are nearing retirement or already retired,. We only have between five and eight years to draw down this expertise or lose it. That's my biggest concern and I'm passionate about skills development but am confident we can do it," said Farnaz.

While ultimately aiming to create local jobs at Fit Britches the business is currently mainly herself supported by interim associates providing specialist services. She envisages that jobs will also be created in sales and marketing, IT and other business disciplines as the venture expands further.

The business was recently named as one of the Best 100 British Start Ups of 2014. Farnaz was also a finalist in the Forward Ladies Women in Business Awards last year for the best start up.

Fit Britches may have come about by accident but Farnaz's business career has been driven largely by her need for flexible working arrangements to meet the needs of her children - two of who have suffered from kidney complaints requiring surgery.

Farnaz used experience gained while working for an online insurance litigation firm to develop her on-line marketing business- eResponse Media Ltd along with an internet competition business prizeboom.com

"The beauty of e-commerce is that you can operate 24/7 and there are many online tools available which you can use to help build custom and operate the business . When I started at the height of the dot com boom the internet was something new and largely uncharted waters . But it has enabled me to focus my energy both into developing a successful business career whilst attending to the needs of my family supported by my partner.

"I originally starred my own business to become financially independent while having the flexibility to blend my career around looking after my family. I didn't realise the growth potential at the time. The future with Fit Britches is very exciting . It will involve the development of 'intelligent' clothing incorporating technology which can help people monitor their body''s health and support a healthy lifestyle.

"it is an area that could lead to people no longer needing routine medical appointments and only consulting a doctor when the need arises. It could help save the NHS time and money. We're not there yet, but with developing technology and fabrics it is possible." she said.