5, 7 or 9 a day?

January 29, 2010 6:57 PM

The UK Government suggests everyone eat 5 serves of fruit and vegetables per day. However, Australia recommends 7 (2 fruit, 5 veg) and the US National Cancer Institute recommends 7 for women and 9 a day for men. What gives?

In the UK, the 5-a-day campaign has been successful in getting people to eat more fruit and veg to reduce the risk of cancer and heart disease. It's on billboards, it's marked on the fruit and veg products you buy, it's frequently quoted by commercial advertisers. You will often hear people refer to getting their 5 serves as though it's a fundamental rule of good health.

Yet it seems that science points to 7 and 9 being the proper targets for daily serves of fruit and veg. Why has the UK gone for such a small target -- is it a case of compromising on a target that is simple and more attainable, even though it's not recommended for most people on the evidence?

posted by dontjumplarry to Health & Fitness (12 answers total)

I would suspect that the UK standard has been revised less recently then the Australian or US standards. Do you have that information?
posted by onshi at 7:09 PM on January 29, 2010

Fruit is really expensive in the UK. And it's not a major cash crop.
posted by jb at 7:13 PM on January 29, 2010

Fruit is really expensive in the UK. And it's not a major cash crop.

Consequently, the lobbyists for the fruit and vegetable industry haven't paid their way to a government recommendation to be constantly eating produce and the UK Department of Health is instead suggesting something realistic.
posted by Mayor Curley at 8:01 PM on January 29, 2010

Yet it seems that science points to 7 and 9 being the proper targets for daily serves of fruit and veg. Why has the UK gone for such a small target -- is it a case of compromising on a target that is simple and more attainable, even though it's not recommended for most people on the evidence?

I don't know about the science, the truth is that these recommendations have to be easy to understand. So the committee writing them has to turn a lot of complex science into a few simple rules. I would not be surprised if the process went like this:

1) The public currently eats 1-2 servings of fruit a day which we know is too little
2) If we suggest something crazy like 10, they'll just ignore it
3) How about 5? That's about double, right?
4) Unanimous consent ensues.

Of course science can't tell us how many portions of "fruit" to eat per day - whoever writes these rules has to take a whole bunch of bits and integrate it, you can't give the public advice like "eat 200 mg of vitamin Y a day" because it won't be followed.

Apparently the recommended number of units of alcohol in the UK was based on a committee of doctors basically agreeing as to what was "a lot" - a number that ends up well below what can be strictly justified based on the science.

So I would guess that Americans and Australians already eat more fruit, so the committee felt that they could up the number without turning people off.

If this seems overly Machiavellian, read up on how the "30 mins of moderate excercise 3 /week" came about. The science pointed to 45 mins of very strenuous exercise 3 /week and moderate exercise the rest of the week. The thing is that if you make a recommendation like that to people who have never gone to the gym, they'll switch off rather than partially implement it - thus we have our current lukewarm exercise recommendation.
posted by atrazine at 8:58 PM on January 29, 2010 [3 favorites]

Actually, the USA has had its own 5 a day program -- now replaced by a more individualized one (as has the old Food Pyramid).

In any case, as atrazine points out, and Mayor Curley in another way, public health in the nutrition arena is fairly well political. You want a simple message, you want to appear to be advocating healthy foods but not to demean important cash crops, and in the end you're only using an average guideline anyway because everyone is different. Ultimately you could just simplify it down to "more" for the vast majority of the population.

I wouldn't get hung up on the specific numbers.
posted by dhartung at 9:24 PM on January 29, 2010

Definitely pragmatism, here. 5 a day is a pretty high target for the British diet -- especially the Scottish variant. I have friends, healthy middle class friends, who have no idea how they can fit enough fruit and veg into their diet to make it to 5 a day.

If the recommendation was 9, nobody would even try.
posted by bonaldi at 9:26 PM on January 29, 2010

I think pragmatism may also be the answer. This advice is aimed at lower socio-economic groups who have the worst health. For these groups fruits and many vegetables have been, until the last couple of decades, a relatively small part of the typical diet. So five a day may possibly represent an achievable target.

Also, I would check portion size to be sure that isn't affecting the advice.
posted by Sova at 10:33 PM on January 29, 2010

Fruit is really expensive in the UK.

At the risk of flatly contradicting you, fruit is not especially expensive in the UK. However, you are correct when you say that the fruit industry is not a big deal, economically speaking.
posted by rhymer at 1:43 AM on January 30, 2010

It was widely reported recently that the UK government felt anything above 5 was unrealistic and so aimed low with their campaign.
posted by fire&wings at 2:10 AM on January 30, 2010

Tentative answer to derail: I think it's based on a common 3-meals-a-day model. The 5, 7, and 9 are extensions of 1-serve-per-meal, and essentially saying "snack on fruit between meals" and/or "add an extra serve of veg to your meals".

I realise that it doesn't necessarily work mathematically, but odd numbers greater than 3 probably have an unconscious psychological effect like I described;all communicating a message that "3 is not enough".
posted by UbuRoivas at 4:58 AM on January 30, 2010

rhymer -- I lived in the UK, and fruits such as apples were twice or more as expensive as in Canada or the US. I remember paying about 60p ($1.50) for a single apple, in the same grocery store where I could get a candy bar for 35p. That is expensive, both compared to prices elsewhere and to the local prices for other foods. At the same grocery store, 8 sausage rolls were 95p, while a package of greens (the cheapest green vegetable) of less weight was 99p and basic spinach (no fancy baby stuff) was £1.29. There was a local farmers' market, but that just sold nicer fruit at the same price. And this was not 30 miles from a fruit growing area. I'm pretty educated and I care about eating well. But while I was living in Britain (albeit on a low wage), the only way we could afford to eat fruit the way similarly waged people can in Canada and the US was from picking our own from our friends' tree.
posted by jb at 5:20 AM on January 30, 2010 [1 favorite]

At least in the U.S. a serving is quite small (1/2 cup). A large apple or orange will give you two servings of fruit, and a large bell pepper, 2 servings of vegetable. I think most people read "5 servings of fruits and vegetables" as "5 fruits and vegetables" and are daunted at the idea of chomping through, say, an entire green cabbage or at filling their fridge with vegetables.
posted by bad grammar at 11:40 AM on January 30, 2010 [1 favorite]