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Since 2009, hypnosis has been a popular method for losing weight following celebrity success stories such as Nigella Lawson, Sophie Dahl and Lily Allen slimming down after hypnotherapy. And over the past two years, there has been an increase in hypnosis apps and virtual gastric band fittings helping people shed half their body weight by tricking the body to thinking it can only eat smaller portions.

So, could you lose weight without dieting? We break down three popular hypnosis treatments that claim to aid long-term weight loss.

1. Traditional hypnotherapy

What is it?

You are guided into a state of deep relaxation by a hypnotherapist so that they can access your unconscious mind and reprogramme your psychological connection to food.

Once you're relaxed, the therapist will suggest new ways of thinking through visualisations, such as envisioning how you would like your body to look, the levels of fitness you would like to achieve and you attaining your weight loss goal.

Does it work?

According to the Journal of Clinical Psychology, hypnosis has been shown to be an effective aid in the process of weight loss in some cases. However, whilst many claim to have lost weight thanks to hypnosis, it is crucial to adopt a healthy diet and take plenty of exercise to see optimal results. The Mayo-Clinic states, "don't rely on weight-loss hypnosis alone because it's unlikely to lead to significant weight loss."

Any slimmers expecting a quick fix can think again - it can take between 21-30 days of hypnotherapy to achieve any long-term weight loss, and typically starting from £195 a session, it doesn't come cheap.

2. Virtual Gastric Band

What is it?

Much like the real surgery, the hypno gastric band is 'fitted' by putting the patient into a state of relaxation (like anaesthetic). The therapist will use visualisation techniques to reduce the amount of food the patient can eat without feeling full.

Does it work?

Debateable. Many have reported drastic weight loss in short spaces of time.However, those expecting instant results without hard work are in for a surprise - as with a real gastric band, lapses are likely and endless grazing will pile the pounds back on.

3. Hypnosis Apps

What are they?

For a fraction of the price of both real and 'virtual' gastric band fittings, smartphone and tablet users can download hypnosis apps to help them lose weight.

Do they work?

Clinical hypnotherapist and former personal trainer Terrrance Barnardt launched The Train Trip in 2014. The app uses a series of hypno-therapeutic tracks using positive suggestions to help listeners achieve their weight-loss goals and focuses on the power of the mind rather than diet and fitness. His methods have garnered rave reviews and celebrity fans including shoe designer Christian Louboutin. (Available from iTunes and Google Play, £9.99)

Several people have reported dramatic weight loss with the use of hypnosis app Easy Loss (available from iTunes and Google Play, £4.99), which features podcasts, a food diary, water diary and support group to help you through your weight loss journey.

As with other methods of hypnosis, these apps do not serve as quick fixes and take dedication and hard work to achieve great results. Whilst they may help you think differently about food, it's important to opt for nutritious meals and snacks and exercise regularly.

Isa Jaward

Isa Jaward is a journalist from London who has written for the likes of Time Out, The Guardian and Music Week.