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Tuesday, November 10, 2009

The myth of 5 a day - people never ate that much fruit and veg

cool cat by psyberartist from flickr (CC-BY)NHS (to American readers - it's the British socialized medicine destroying UK, and coming to destroy your country too now) strongly promotes the idea of eating "5 servings of fruit and vegetables" a day, with which I disagree on so many levels.

Here's a quick summary of the alleged benefits, straight from their website:

  • They're packed with vitamins and minerals.
  • They can help you to maintain a healthy weight.
  • They're an excellent source of fibre and antioxidants.
  • They help reduce the risk of heart disease, stroke and some cancers.
  • They taste delicious and there's so much variety to choose from.
That's all nonsense.
  • You are extremely unlikely to have vitamin and mineral deficiency, and if you suspect some (or want to get pregnant, have symptoms of anemia etc.), get real multivitamin pills, or supplements of the right kind. Most fruit and vegetables are fairly unimpressive as for their vitamin contents anyway - for all practical purposes most fruits are just water and sugar, and have been selected this way by farmers, as larger and sweeter fruit sells better, and vitamins don't have taste.
  • There's absolutely no evidence linking fruit and vegetable consumption to weight - you get stable weight when number of calories taken balances number of calories expended, what's possible on any kind of diet, including a really delicious one based on loads of meat and cheese and chocolate that NHS would not approve of. I'll get back to this point later.
  • Fibre doesn't do anything - it just passes through your digestive system and goes right into the toilet. "Antioxidants" are one of those terms that make me rage, as they've been stripped from their original scientific meaning, and turned into pure value judgment, and not even of the right value. Your cells know how to deal with oxidative stress already. That's what they're evolved to do over the last 1.7 billion years. They have plenty of ways to do so. And increasing amount of antioxidants will not help your cells. Meta-analysis of all available data shows clearly that eating more of them doesn't do anything for you, and can even be harmful.
  • There's been no proper long term trials of that kind. There's very few proper long term trials of anything related to diet, and those that are performed invariably show that simple diet advice (eat this, don't eat this) doesn't work - and unless your diet is spectacularly wrong you'll be fine as long as you have adequate exercise, decent portion control, and don't smoke.
  • As any kid will tell you, fruit and vegetables taste awful - if they were delicious people wouldn't need NHS's bothering about them. Do chocolate and ice cream need NHS campaigns? Obviously not. That's because chocolate and ice cream are tasty, while fruit and vegetables are not, at least not in those ridiculously large amounts.
So it's wrong on all counts. Anyway, that's not what I wanted to post about - I just get distracted easily. Oh, something shiny. Oh, funny cat. I go for all distractions. Now back on track.

What I wanted to talk about was the myth that people used to eat enormous amounts of fruit and vegetables - 5 servings a day or more as NHS advices, and that's it's something modern that they do not do so now. Let's look at FAO data, annual consumption per capita of fruit and vegetables, as far back as it goes (that's unfortunately not that far back). I included some particularly fat countries (USA, Mexico), a particularly healthy country (Japan), random countries from Europe (France, Germany, Poland, UK), and totals for Europe and World. For interest of science I'll say I selected countries and criteria before I had a first look at the data, so it's not a biased selection, but feel free to look at others.

Vegetable consumption, 1961 to 2003, increased in all selected countries:
  • France - 150kg to 142kg
  • Germany - 49kg to 90kg
  • Japan - 95kg to 104kg
  • Mexico - 25kg to 58kg
  • Poland - 91kg to 100kg
  • UK - 60kg to 91kg
  • USA - 93kg to 123kg
  • Europe - 90kg to 117kg
  • World - 63kg to 117kg
Fruit consumption (excluding wine), 1961 to 2003, also increased in all selected countries:
  • France - 53kg to 95kg
  • Germany - 79kg to 113kg
  • Japan - 29kg to 54kg
  • Mexico - 57kg to 120kg
  • Poland - 18kg to 47kg
  • UK - 55kg to 115kg
  • USA - 76kg to 113kg
  • Europe - 65kg to 88kg
  • World - 38kg to 62kg
Fruit and vegetables together, 1961 to 2003:
  • France - 203kg to 237kg (+17%)
  • Germany - 128kg to 203kg (+59%)
  • Japan - 124kg to 158kg (+27%)
  • Mexico - 82kg to 178kg (+117%)
  • Poland - 109kg to 147kg (+35%)
  • UK - 115kg to 205kg (+79%)
  • USA - 169kg to 236kg (+40%)
  • Europe - 155kg to 205kg (+32%)
  • World - 101kg to 179kg (+77%)
So consumption of fruit and veg in the last four decades drastically increased - and so did obesity, heart disease and so on. Increase in UK and Mexico were particularly large - and these are some of the fattest countries in the world, something that was not true in 1961. In increased least in Japan - by far the healthiest of developed countries. NHS was really successful at making Brits eat 5 servings a day - making 63.8% of them overweight in process. So much for fruit and veg consumption helping fight obesity? Here's the list of selected countries ordered by fruit and veg consumption and percentages of overweight people in them:
  • France - 237kg - 40.1%
  • USA - 236kg - 74.1%
  • UK - 205kg - 63.8%
  • Germany - 203kg - 60.1%
  • Mexico - 178kg - 68.1%
  • Japan - 158kg - 22.6%
  • Poland - 147kg - 47.5%
Is it just me, or do countries that eat more fruit and veg tend to be fatter, not thinner? The answer is probably a lot more like this instead:
And it's not like 1961's fruit and vegetable consumptions were unusually low - they were in fact unusually high by historical standards - normally it was impossible to eat any other than those that grew in your region, in harvest time, what all amounted to very very little compared to what people eat now with globalized industrial agriculture.

The take home message: Ignore NHS; eat chocolate, ice cream, beef, cheese, or whatever else you find delicious. In reasonable amounts.

28 comments:

Anonymous said...

even 113kg of fruit is not much. that's 1 apple and less than one pea per day.

besides, i don't understand how you can link obesity to fruits/vegetables? people gain weight, eat more fruits (1 apple, 1 pea per day)and that makes them obese? really?
maybe it is because the tomato is filled in a big mac and the apple is filled in a baked apple pie...
mcdonald's is the largest purchaser of pork and beef in the US (probably not tiny in europe either).

taw said...

113kg of fruit is more than ever in history. People are not made to eat that much fruit.

Also, 113kg a year is 310g, medium apple weights 180g according to USDA, so that's 1.7 apples a day.

You cannot say it's "not much" without pointing to some society where people ate far more than that - and such society never existed.

From nutritional perspective it doesn't matter if you eat apples raw or in an apple pie, or if you eat a tomato on a home-made sandwich or in McDonald's burger. It's the same nutrition.

Anyway, my point isn't that fruit make people obese - eating too much makes them obese, no matter what kind of food you're overeating, and pretending that fruit and veg have some magical slimming properties is nonsense.

lamby said...

I think the actual number in "5 a day" is misleading; if I wanted the populace to consider nomming less crap and perahps some vegetables once in a while, I would probably choose a high number like 5 in an attempt to induce guilt.

taw said...

lamby: The guilt doesn't seem to be working, as people turned from traditional food that served them well (and did not contain anywhere near as much fruit&veg - these were impossible to obtainable for most of the year!) to modern crap food that contains far more fruit&veg and makes people fat.

Anything that has some fruit and veg seems to count if supermarket labels are to be believed, no matter how much added sugar it has, and how much processing it went through (orange juice is virtually indistinguishable from Coke from nutritional point of view). So campaigns like that fail at making people healthier.

bosie said...

food is a huge business. when the FDA approves a label on chips saying they are healthy because they were fried in a certain oil, the whole system is ridiculous.

above i said 1 apple and little less than 1 pea a day. which i don't find much to be honest.

as for a society. i would say there are/were many societies eating more than the europeans do nowadays. any society which has a diet based on lentils or rice will most likely eat/ate more vegetables/fruits than we are currently doing. not nordic countries, but (ancient)greek/italy/spain, asian countries and latin america, or am i wrong? (mind you: don't compare what we are eating now, obviously that number is higher, read the other day austrians on average eat 30% more than we should)

my point was directed at obesity. the problem is no the apple, it's the apple pie. it's not the tomato, it is the big mac.
you should look at it another way:
according to fao, germany consumed 310g/day, giving the average german 135 calories per day. that's 6% of the daily calories intake. that can not be seen as overeating fruit. period. but i am not pretending it's some magic food either ;)

i agree on the point you are making on the overeating though.

taw said...

bosie: You are most likely wrong about ancient diets. We don't have very good ancient data, and what we have very often describes upper class eating; but what quick googling indicates is pretty suggestive:

Ancient Greek cuisine was based on cereals, olive oil, wine, and some beans. Depending on place also pork and seafood. Fresh fruit and vegetables were too expensive, and only rich people ate them.

Likewise in Rome, fruit was upper class food; working people ate emmer bread, beans etc.

I believe you will find very similar results no matter where you look.

bosie said...

the link you sent me wasn't really pushing your argument. dried fruits are high in carbs, ergo you need to eat (way) less. but yes, ancient greek might have not eaten that much fruit.

but since rice is not a vegetable but a grain, i obviously take the asian culture back.

Anonymous said...

http://www.sciencedaily.com/releases/2009/01/090122081334.htm - Mediterranean Diet Reduces Long-term Risk Of Subsequent Weight Gain And Obesity Among Adults

http://www.sciencedaily.com/releases/2008/08/080815130413.htm - New Mushroom Study Shows The Power Of Energy Density

http://www.nature.com/ijo/journal/v32/n6/abs/ijo200821a.html - Vegetable-rich food pattern is related to obesity in China

Not to mention the hundreds of studies that show eating fruits and vegetables makes you healthier. It's not just about obesity.

taw said...

Anonymous: The studies saying you're quoting say "The data analysis of this study was limited by the number of participants", "over the four-day test period", and "vegetable-rich food pattern was associated with *higher* risk of obesity" (but they count rice as a vegetable, so it doesn't really compare), respectively.

Not exactly convincing arguments, is it?

Anonymous said...

Ah,that style of argument. It's about a 100 times more scientific than the anecdotal approach you have taken.

Anonymous said...

Fruits and vegetables don't have magical slimming powers. What they do have, however, is a smaller number calories per gram than do their calorie rich cousins like beef and cheese. What you wind up with, then, is fewer ingested calories for the same amount of food eaten. Want to lose weight? Eating a vegetable salad without dressing instead of a cheeseburger of the same volume will help you achieve that goal. Put another way, if you replace high-calorie foods with low-calorie foods, you will lose weight. As you suggest, you can alternatively lose weight by lowering the amount of high calorie foods you consume.

taw said...

Anonymous: The idea that people regulate amount of food eaten by volume is nonsense. If it was true, Coke would have magical slimming properties, as 100g of coke have only 40kcal, and 100g of apples have 52kcal.

There were also studies showing no relation between caloric density and total calorie intake in kids.

(Anyway, commenters seem to have missed it, but the main point of the post was that the idea that people used to eat huge amounts of fruit and vegetables is a myth, not to describe research on their effects on health)

Anonymous said...

Taw, you said "The idea that people regulate amount of food eaten by volume is nonsense."

Very interesting. You're basing that statement on what exactly? A single un-cited study? If they don't use volume, then what do they use to regulate the amount of food eaten? Number of calories?

By that reasoning, I can either eat a 100g piece of beef (there are 332kcal in 100g of beef with 30% fat) or 638g of apple and be equally satisfied with my meal.

A 100g piece of beef is less than half of a petit filet. This is a tiny piece of meat, even by european standards. This would be like eating about 75% of the quarter pound beef patty out of a McDonald's hamburger. 638g of apple is about 3 and a half medium (3" diameter) apples. You get 6 times the volume of food if you eat the apple instead of the beef. Try it out for yourself and see if your theory holds.

Regardless of what you claim, the fact is that foods that contain a lot of bulk fiber cause you to feel full. If you feel full, you stop eating. If you stop eating after having consumed 52kcal instead of 332kcal, then you're on your way to losing weight.

And just because commenters aren't addressing the main point of your post doesn't mean they missed it.

And if you think fruits and vegetables taste awful, then you're not doing it right. Go eat a honeycrisp apple or an heirloom tomato.

Matijs van Zuijlen said...

Anonymous, the relation between amount of food eaten is actually more complicated than either volume or number of calories (oh boy, that was a surprise now, wasn't it?).

For example, protein makes you feel full more quickly than carbohydrates, which apparently is the real reason the famous diet whose name I can't remember in my jet-lagged state works. Oh yeah, Atkins. (Source: some episode of Horizon I saw, but I can probably look it up if necessary.).

Oh, and 100g of meat for an evening meal sounds just about right for me. Then again, I'm below average height and also quite thin, so there you go.

taw said...

Matijs van Zuijlen: Volume explanations are just unbelievable, as food is basically nutrients (which have more or less the same calorie density) + water, and it really shouldn't matter if you eat small portion of high calorie density food and drink a glass of water with it, or eat big portion of low calorie density food. By the time it's digested it will be the same.

If volume really made people feel satiated, drinking more water would be the best diet, what's easily demonstrated not to be true.

Divided Mind said...

With all those nitpickers around, I'm surprised nobody caught this one:

Vegetable consumption, 1961 to 2003, increased in all selected countries:
* France - 150kg to 142kg
(...)

[emphasis mine -- Divide]

David said...

Ive found over rougly a two year period by always drinking lots of water with my meals I feel "more full" and have a reduced capacity to eat high volumes of food. I love food and feeling full, thats my problem. I know I need to eat less food than I want and thats a constant battle. I like to eat 4 slices of bread in sandwiches and again over the 2 years by eating 2 slices and rinking lots of water i discovered that I "felt full" most of the time and at the end of 2 years I felt ridiculously bloated if I ate 4 slices.

I question the data though on food consumption. Recently there was a program about food waste in britain. The "food consumption" data youre pointing at is probably "food sales" data, which isnt quite the same thing. I totally agree though that the 5 a day is probably rubbish, aimed at, targeted for the same people who will buy total war games and complain about how buggy they are.

taw said...

David: Yes, consumption statistics are at household doors, and we can imagine that as people have more food waste is larger, and calorie consumption increased less than data shows, but here I'm mostly analyzing ratios between different food types, and these are not affected by waste issues.

There's no clear difference between thirst and hunger - they're two sides of the same thing really. If you don't drink enough, you feel as if you were hungry.

Anonymous said...

Mexico all they ate was corn it was there cheapest food I almost for sure because (this Is ancient mexico) they didn't have wheat so this was there staple crop rich people ate coffe and other delicasy including fruit

Anonymous said...

I'm who wrote the one above me not who wrote the others I well have thus at the end now

-Justin


-Justin

Noumenon said...

This post doesn't really live up to the headline when it only goes back to 1961.

mr.will said...

Fibre can be very important to regulation of blood sugar (soluble fibre found in vegetables) and digestion (insoluble - found in wheat grains etc) - saying that only as someone who hasn't had enough in the past and had to have my intestines operated on as a result of poor digestion! Brock lesnar (UFC) had the same.

Of course, the point about 5 a day being a myth is totally correct - a marketing slogan if anything......

Anonymous said...

You lot don't have a clue what your talking about (sorry) but the original blog is right and it's not to do with 'studies' it's BIO CHEMISTRY!!!

Fruit IS sugar (fructose) and it is metabolized by the liver and stored as glycogen and then when glycogen stores are full the excess is stored as FAT.

Dietary fat dose NOT make you fat.

The other bit about sugar making you fat is INSULIN. When you eat carbohydrates it all ends up as glucose to be used as energy by every cell in your body. It is insulin that pushes the glucose into your cells and in turn STOPS those cells using fatty acids deposited in the adipose tissue (your fat cells) and so stops you losing wait if you are obese.

Anonymous said...

What a jerk!
Fruit and veg are delicious. I'd much rather eat something natural that I know what went into it, rather than some skanky McDonalds plastic burger!

What absolute, unsubstaniated rubbish!

Anonymous said...

Wow. You are so wrong on so many levels I don't know where to start. Here, educate yourself:

http://nutritionfacts.org/video/uprooting-the-leading-causes-of-death/

mcpinier said...

I came across this article while searching for useful information about nutrition on the Internet and was totally incensed by what you wrote. Your whole text is stupid, a complete misrepresentation of the facts. Fruits and vegetables are just innocent bystanders in the epidemic of overeating that is affecting most industialized countries to some degree. Just take the statistics and look at the increase in the US in dairy and meat consumption and you'll see that it's many many times more important than the increase in fruits vegetables (and most Americans count french fries as vegetables). We're just eating more, period. And the bulk of it is animal products. Please don't write such stupid things.

taw said...

mcpinier: I'd recommend taking a look at FAOSTAT data before going into angry rants, since reality is very different from what you think.

Anonymous said...

Wow, what a load of ill-informed rubbish.

NHS (to American readers - it's the British socialized medicine destroying UK, and coming to destroy your country too now)

I mean, seriously?! Please go away and keep your rubbish off the internet, where people might mistake it for fact.