Mass marketed diets rarely work for individuals because they are unable to account for individual situations, it has been suggested.
Harley Street nutritionist Yvonne Bishop-Weston of Foods for Life said: "Mass marketed diets also rarely take into account individual needs, underlying medical conditions such as masked digestive disorders, food intolerance and hormonal imbalance that can thwart weight loss.
"We are not all the same."
She added that eating natural foods was one of the best ways of keeping off weight.
In this light, recent research from Sainsburys could prove worrying as students were found to eat a large amount of ready meals during their time at university.
Earlier this month, Jenny Craig revealed that 89 per cent of women surveyed in the UK claimed to have tried to lose weight at some point in their lives.
The number one reason for wanting to reduce their size was appearance.