The five-a-day fallacy: How to actually get enough fruit and veg in your diet

Five-a-day may be catchy, but according to health experts, it's not always the best for our diet.

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Published: January 28, 2023 at 5:47 pm

Five-a-day started out as a health marketing slogan in the US.

“[It was] loosely linked to populations that had more fruit and vegetables having lower risk of heart disease or longer lives,” says Dr Duane Mellor, a British Dietetic Association spokesperson and registered dietitian. “The World Health Organization data now shows eating half a kilo of fruit and vegetables daily is a minimum to see lower instances of disease.”

Five good handfuls should provide this quota, but the more the merrier.

Five-a-day may be super catchy, but in practice it can be problematic. Fruit juice counts as a daily portion in the UK, even though you’re getting the concentrated sugar hit of many more fruits than you’d eat, without the fibre, potentially causing a sugar rush and tooth decay. In the UK, we don’t count starchy, carb-rich potatoes (or yams), but in Australia spuds are allowed – after all they are a key source of vitamin C.

“A simpler message is try to eat as many different fresh or frozen – or if that’s not possible, tinned – fruit and vegetables as possible, in two meals a day,” says Mellor.

Mellor says giving the vegetables a starring role in meals is key to long-term health benefits. “We may be tempted to eat more fruits because they taste nicer,” he says. “Likewise, condensing the fruit and veg down to a smoothie, you’re losing the foundation, the building blocks of meals. If you take the vegetables out of the meal, the risk is your meal is going to comprise things with less vitamins, minerals and fibre and more calories. You need to make vegetables the bulk of a meal, and then try to make them interesting.”

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Variety is important, agrees Dr Sarah Berry, associate professor of nutritional sciences at King’s College London, and chief scientist at personalised health research company, ZOE. According to Berry, recent research by ZOE’s partner organisation, the American Gut Project, has highlighted the importance of eating a variety of fibre from around 30 different plant species as being key to better health.

While some argue that we should be surpassing five portions of fruit and veg a day, Berry is cautious. “The majority of people in the UK – 70 per cent of adults and over 80 per cent of children – do not reach the five-a-day target, so changing it to something more ambitious may not be helpful,” she says.

Dr Koula Asimakopoulou, a reader in health psychology at King’s College London, warns that short catchphrases are not enough to spark behaviour change. Instead, we need to consider SMART objectives. SMART stands for specific, measurable, achievable, realistic and time-based targets.

“Having a goal is not equivalent to performing it,” she says. “Psychologists have discovered that if you have an intention to get five-a-day, you’ll be most likely to translate it into behaviour if you plan when, where and how you will achieve this goal, along with forming a Plan B for what you will do if the when/where/how plan is broken by life events.”

About our experts

Dr Duane Mellor is a senior teaching fellow and associate dean for public engagement in the college of health and life sciences at Aston Medical School. They are also a British Dietetic Association spokesperson and previously worked as a senior lecturer at Coventry University.

Dr Sarah Berry is associate professor of nutritional sciences at King’s College London, and chief scientist at personalised health company ZOE. She is also the lead nutritional scientist on the PREDICT programme, assessing the metabolism of 3,000 people across the UK and US.

Dr Koula Asimakopoulou is a reader in health psychology at King’s College London. She is also a member of the Health Care Professions Council (HCPC) and chair of the Bromley NHS Research Ethics Committee.

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