More than 30m adults in Britain are not eating the recommended five portions of fruit and vegetables a day, a study has revealed.
The findings suggest that a "disturbing" lack of knowledge about nutrition and the effect of the economic downturn are to blame.
The survey of 10,000 adults, commissioned by the Health Food Manufacturers' Association (HFMA), found that the number of adults not getting their five-a-day has increased by 5% since 2010 to 61%. And it is young people leading the downward trend with some 70% of 18-24 year olds failing to meet the government guidelines.
The poll revealed a lack of understanding of fundamental nutritional knowledge with one in 12 of those questioned believing that items such as tomato ketchup, Terry's Chocolate Orange and strawberry ice cream count towards five-a-day.
Over a third (37%) felt their diets had worsened since economic downturn with the combination of small pay increases and soaring food costs impacting negatively on supermarket choices.
The HFMA poll, which is conducted every two years to analyse healthy diet trends, also revealed an unhealthy attitude to junk food - and interestingly, women were worse offenders than men.
Almost 84% admitted to eating junk food with women more prone, justifying their junk food habit as "more comforting" than healthy foods.
Half of 18 to 24-year-olds said they chose to eat junk food because they preferred the taste while a third said they opted for it because it was "less expensive".
Almost a quarter were confused about the government guidelines on vitamin and mineral intake, putting them at risk of deficiencies. With half of the UK adult population deficient in vitamin D, it was not surprising to discover 50% of those surveyed were unaware of the government's recommendations on vitamin D intake and did not recognise any of the symptoms of vitamin D such as rickets, bone pain, muscle weakness and tiredness.
Graham Keen, executive director of the HFMA, said: "Everyone should know that the best solution for most people to consume key nutrients, such as vitamins and minerals, is to eat as healthy a diet as possible.
"However, it should be noted that a daily vitamin supplement provides important nutritional insurance for millions of users looking to safeguard their nutritional intake."
Nutritionist, Dr Marilyn Glenville PhD said of the findings: "The trends in this survey are extremely worrying and it is of utmost importance to public health that messages such as 'five-a-day' are seen to be working.
"Nutrition is so closely linked to good health and prevention of illness that we need to prioritise healthy food options - and unfortunately this survey does back-up the fact that most adults in the UK are either overweight or obese.
"In terms of supplements, these can never be a substitute for a healthy diet but we know that compared to the 1930s, fruit and vegetables can be depleted in minerals by an average of 20%, and that other foods like dairy have lost minerals, such as iron in milk by over 60%. So even with the best will in the world, it is difficult today to get everything we need from food alone."