"I was like E.T. My skin was like a snake's skin. My cheeks were sunken and I was a very weak and small girl before I knew that I had celiac disease," says 26-year-old Yağmur Dilara Şenkal, a customer representative at Istanbul's only 100-percent gluten-free restaurant.

Dilara is only one of the 35,000 people diagnosed with celiac disease in Turkey. It is thought that the real number is much higher, as there are many people who are not even aware that they have the condition.

Celiac is an autoimmune disease which is triggered by a reaction to foods containing the protein gluten-including wheat, rye and barley. It is a sensitive disease, which requires special care and a life-long gluten-free diet.

As gluten is also used as a texture enhancer, stabilizer and thickener in many products, some health experts say 80 percent of foods contain gluten. Maintaining this diet is not easy.

This has fuelled demand for gluten-free foods worldwide. According to a report by U.S.-based research company MarketsandMarkets, North America dominated the gluten-free products market, followed by Europe in 2013.

The gluten-free products market is projected to reach $6.8 billion globally by 2019.

Back in Turkey, awareness about the condition is growing. "Even a small piece of bread can cause sickness like stomachache, diarrhea or nausea," says Hilal Batmaz, a dietitian at the Private Konak Hospital in Kocaeli province. "It is not a fatal disease by itself, but may cause serious diseases if patients are not careful about their diet."

However, if patients stick to their diets, they will live a healthier life.

"Twenty years ago there were no gluten-free products in Turkey," says Oya Özden, 52, president of the Istanbul-based Society of Living with Celiac. "Life was so difficult for me at that time," she adds.

Özden learned of her disease first in 1995 when she was 32. She neither knew what celiac was nor what she would do after her diagnosis. A very difficult process started for her. She had to bake her own bread - an essential part of Turkish cuisine - for a long time, and had difficulty in finding the right things to eat.

Four years later, in 1999, the Istanbul Metropolitan Municipality's affiliate corporation "People's Bread" produced gluten-free bread for the first time in the city. It later expanded its products, ranging from hamburgers to cookies.

Some flour, pasta, biscuit and dessert firms followed the bread company. In the last 15 years, the number of labels producing gluten-free products has increased across the country.

Eskişehir-based biscuit company, ETİ, started selling gluten-free biscuits in 2003 and Istanbul's Sinangil Flour Company produced gluten-free flour in 2007.

Famous Istanbul-based desert company, Güllüoğlu, has also been alerted to this new market for celiac patients. It joined the companies producing gluten-free goods in 2013.

"It is a social-responsibility project. People with celiac are very glad to able to find gluten-free baklava [traditional dessert] here. The interest is increasing day by day," says Nilgun Demirel, a food engineer at Güllüoğlu. "We have also started sending baklava to Germany, France and America as well."