Eating five portions of fruit or vegetables on a daily basis is not enough for people to properly tackle their high stress levels, an expert says.

The five-a-day guideline also does not efficiently counteract the amounts of toxicity emitted from the world's modern environment, according to a representative from Foods For Life.

Yvonne Bishop-Weston, nutrition consultant at Foods For Life, said: "The government message is confusing, because there is no clear evidence anywhere that says that five a day is perfect for preventing disease. We don't recommend five a day, we recommend eight a day in our clinics."

Ms Bishop Weston added that individual fruit and vegetables contain nutrients that are fundamental for bodies to function properly, with fibre being particularly important as it helps bodies to detoxify.

Meanwhile, a Datamonitor survey released in October discovered that two-thirds of Brits are either overweight or obese.

The organisation also estimated that 16.5 million people will be obese by 2014.