With such a huge variety of diets now available Helen explores which are the best for you and whether diets really are the answer to losing weight.
In the programme, Jennifer - who is from the British Dietetic Association (the BDA) - has identified a number of diets the BDA feels that, while they may be fine in the short term, are unsustainable over the longer term.
Ketogenic Diet - "This is very, very low in carbohydrate only about five per cent of the energy intake is coming from carbohydrate….Absolutely people will lose weight on this diet but it is not sustainable in the long term."
Alkaline Diet - "They think that by eating this food you can change the pH of your body and actually make yourself more healthy - it’s total rubbish…..the whole sort of science that this diet is based on is actually flawed."
Raw Vegan Diet - "‘The issue that we have with the raw vegan diet is the fact that the foods aren’t being cooked. Some of those fruits and vegetables are actually a lot better when they are cooked."
She learns all about personalised DNA testing which could potentially make dieting a thing of the past.
And Helen returns to Liverpool John Moores University to find out the results of our ‘fat burning’ pills test.
NHS weight loss guide - popular, free 12-week diet and exercise plan.
NHS Boost your health and fitness - with fun and practical ideas to get active and improve your general health.
The British Dietetic Association - Professional association and trade union for dieticians in the United Kingdom.
Diets: New Year, New You? will be broadcast on ITV at 7:30pm on Thursday 4th January.