Shelli Henderson has explained how she lost seven-and-a-half stone with just her Blackberry mobile phone and a cheap app.

A ST ALBANS bar manager is “appy” to be a whopping seven-and-a-half-stone lighter thanks to following a calorie-counting diet application on her mobile phone.

Shelli Henderson, of Cottonmill, has used her Blackberry “smart” phone to help crack bad eating habits which resulted in her weight ballooning to 18 stone, forcing her to wear size 22 clothes.

Now weighing ten-and-a-half-stone and a healthy size 12, the former Marlborough School pupil said: “I feel like a different person, like I have come out of my shell and even my personality has changed.”

Shelli, who works as a bar manager at HSBC group management training college in Bricket Wood, explained: “When I left school the weight started to creep up slowly and then ballooned last year.”

She attempted “every diet” but nothing shifted the weight for long. Shelli said: “Any diet that you have heard of, I tried and if there was a week where I didn’t lose weight I would give up.”

However that yoyo-dieting regime came to an end when she bought the app, the Livestrong calorie tracker, for �1.99 in May last year, which basically counts the calories for you.

Shelli explained: “I found it so much easier because it is so simple. You enter your height and weight and your daily activity level and it works out the number of calories you can eat a day.

“As you enter in the food you eat during the day, the app adds the calories up for you and tells you how many calories you have left. It’s simple and it just works.”

Shelli said that seeing the calorific value of food encouraged her to eat healthily.

She went on: “Most of the weight came off in the first eight months, and the last two months have been the hardest.”

Asked for some tips on losing weight, Shelli recommended drinking “enough” water and exchanging the odd meat dish with Quorn, which is made with vegetable protein.

She added: “The only advice I give is to make the right choices. It’s all in the head; you have to make that connection that some food is going to make you put on weight – I don’t think some people make that connection.”

Shelli said some people had been “shocked” at how much weight she had lost.

She added: “Everyone is very happy for me. People are shocked as they can’t believe it. It’s really nice, everybody has been really positive about it.”

Details of the calorie tracker can be found on Livestrong.com – a website built by Demand Media and the Lance Armstrong Foundation, an organisation founded by cancer survivor and champion cyclist Lance Armstrong.