Nutrition 5: Healthy Eating Guidelines

This post is part of a short series about the nutrition material I was required to learn for my personal training qualification.  And learn it I did, I received notification of my score the other day and I managed to hit 97.5%… Now I just have to find some way to extract the information back out of my brain so that I can put the correct information in again…

Anyway.  In this post, I’m going to have a quick look at the overarching healthy eating guidelines that we are given.  I’m not going to go into huge amounts of detail here, because the detail is covered elsewhere.  But hopefully, this just brings it all together in one place.

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What are the general guidelines for healthy eating?

My course notes list the following guidelines for healthy eating, along with the basic, generally accepted reasons for the guidelines:

1. Decrease fat intake to 30% of total calories – eating too much fat makes you fat.
2. Decrease saturated fat intake to 25% of fat intake (or 7.5% of total calories) – saturated fat causes heart disease by means of cholesterol deposits forming in the arteries, which is called atherosclerosis.
3. Eat less animal protein – animal protein often comes attached to saturated fat (see point 2 above), it can cause kidney damage in people with pre-existing kidney conditions, it can cause excess ammonia accumulation in the blood and eating an excess of it can cause obesity.
4. Eat more complex carbohydrates – there are no known clinical conditions associated with an overconsumption of complex carbohydrates.
5. Eat less sugar – eating too much sugar causes dental caries and type two diabetes.
6. Eat more fruit and vegetables – fruits and vegetables contain important vitamins and minerals that we need in order to maintain good health.  Eating more fruits and vegetables helps to reduce the risk of heart disease and some cancers.
7. Eat more fibre rich foods – soluble fibre helps with cholesterol binding and lowers cholesterol levels, which lowers heart disease risk.  Eating more fibre also reduces the risk of certain cancers, notably bowel cancer, and type two diabetes.
8. Decrease salt intake – the consumption of salt increases blood pressure, which increases heart disease risk.
9. Drink more water - dehydration causes a decrease in exercise performance and can be dangerous if allowed to exceed certain levels.
10. Moderate intake of caffeine and alcohol – low levels of alcohol have been connected with lowered heart disease risk.
11. Eat a variety of foods – eating a variety of foods reduces the risk that any one vitamin or mineral will be lacking and decreases exposure to pesticides or other harmful additives.

Just for the record, even writing some of that down makes me feel stupid.  So let’s clarify.

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So what do I think about the guidelines?

Well, here are my comments, along with some links to various resources to support them.  Where I agree with a recommendation, I’ve called it clever.  Where I disagree, I’ve called in stupid (hey, I get to do that kind of thing as a writer).  Where I’m not sure, I’ve said not sure.  

Now bear in mind, if I’ve said not sure then that could be because I haven’t read enough about the topic, it could be that there isn’t enough evidence or it could be that I just can’t get my head around it at the moment.  You’ll just have to take the risk as to which it might be…

1. Decrease fat intake to 30% of total calories – (stupid) – eating too many calories makes you fat.  You can over or under eat using any macronutrient ratio.  Various things can influence people to start eating more calories than they need.  Eating fat is not one of them.  Fat is satiating and tells the body that it is full.  However, eating carbohydrates is not particularly satiating and in fact causes insulin levels to rise quickly.  This in turn causes a drop in blood sugar, which makes you feel hungry.  By this reasoning, if any macronutrient “makes” you fat, it is carbohydrates and not fat.
2. Decrease saturated fat intake to 25% of fat intake (or 7.5% of total calories) – (stupid) – the idea that saturated fat causes heart disease through atherosclerosis is called the lipid hypothesis of heart disease and it has no foundation in science.  If you have a limited patience for minority ideas, especially when they come from a random fitness blogger online, please do yourself the favour of reading Dr Malcolm Kendrick’s book, The Great Cholesterol Con and become enlightened.  If you are too sceptical to believe me and too cheap to buy Malcolm’s book, at least check out these convincing articles by prominent physicians.
3. Eat less animal protein – (stupid) – there is no reason to reduce protein intake and there are plenty of good reasons to increase it.  Dr Lonnie Lowery was so cross with this myth that he wrote a scientific review (Dietary protein and resistance exercise: what do we really know?) about the huge disconnect that exists between academic textbooks and the actual published scientific literature when it comes to protein and athletes.  He concluded that when you sit down and actually look at the literature, there is very little support for any of the dramatic claims.
4. Eat more complex carbohydrates - (stupid) – eating lots of carbohydrates of any kind is a a great way to get type two diabetes and other diseases. The statement “there are no known clinical conditions associated with an overconsumption of complex carbohydrates” is profoundly criminal.  Check out my post on carbohydrates for the research or, again, if you don’t like taking my word for it, check out Robb Wolf’s book The Paleo Solution, in which he gets technical about how carbohydrate consumption is killing people.
5. Eat less sugar – (clever) – eating lots of sugar does everything that eating lots of complex carbohydrates does only quicker.  For more details, refer to Robert Lustig, who would go so far as to say that sugar is in fact poisonous.
6. Eat more fruit and vegetables – (not sure) – this is an area I feel I need to spend more time reading about but here are my thoughts at the moment:
   1. Not relevant for heart disease prevention- Malcolm Kendrick has made it clear that diet has little or no bearing on heart disease risk. So the recommendation to eat more fruits and vegetables for the purpose of reducing heart disease risk is not valid.
   2. Stress is a bigger factor – Kendrick holds that stress is a much more important factor than diet in the incidence of heart disease.  He discusses how the displacement of 400,000 people out of the Finnish region of Karelia led to a massive increase in heart disease in that area.  I am sure very few of those people ate fast food and I’m sure they got plenty of exercise.  But the stress of being relocated still killed them despite these advantages.
   3. Possibly not relevant for cancer prevention – Cancer Research recently published a review of a number of the studies that suggest that cancer can be reduced by eating more fruits and vegetables and this review seems to show that they don’t really do anything significant.
   4. Good for avoiding vitamin and mineral deficiencies – so fruits and vegetables may be useful for avoiding vitamin and mineral deficiencies but more may not necessarily be better.
   5. Speaking personally – I would like to confess that I still eat broccoli every day (as well as a lot of other vegetables) in the vain hope that they might help me avoid all kinds of horrible ends.  I don’t like eating them but I eat them because I don’t want to die young.  However, I don’t see the mechanisms yet by which this vegetable consumption is clearly helping me.  So I am afraid I do need to do a lot more reading before I can begin understand (and therefore blog about) what is going on.  Suggestions for further reading are, of course, always welcome.
7. Eat more fibre rich foods – (not sure) – as I noted above, Malcolm Kendrick has made it clear that diet has little or no bearing on heart disease risk so the recommendation to eat fibre for the purpose of reducing heart disease risk is wrong.  Similarly, the evidence regarding bowel cancer seems to be sketchy, as a famous study in 2005 reviewed 13 prospective cohort studies and concluded that there was no strong correlation between fibre intake and incidence of cancer.  And if you think that eating fibre reduces your risk of type two diabetes then you’re not really listening to anything I’ve been saying.  So again, while I do eat plenty of vegetables and get a good amount of fibre from them, I do suspect that we might be overestimating how much good we do when we purge ourselves.  But, again, I don’t really know yet.
8. Decrease salt intake – (not sure) – the mainstream health media believes that salt causes blood pressure to rise and thereby increases heart disease risk but Barry Groves asserts that “the evidence on which this was based arose from poorly controlled cross-cultural studies carried out earlier in the century. At least in the debates on the desirability of fats and fibre, trials were carried out in an attempt to provide evidence to support the hypotheses, but no similar trials have been carried out in the case of salt. The salt hypothesis has no large-scale studies to back it up. The intervention studies that have been carried out are confined to small numbers of people with high blood pressure, and many of these have failed to show that lowering salt intake has any significant effect on blood pressure in those with hypertension.”  However, Mark Sisson, not usually backward in trashing myths, isn’t convinced.  Again, I need to get into the detail here and make my mind up.
9. Drink more water - (not sure) – while it is hard to disagree with the importance of avoiding dehydration, this may well be another one of those areas like vitamin and minerals where enough really is enough and more doesn’t necessarily equal better.  Check out my discussion about water last week for more details and to see why I can’t make up my mind.
10. Moderate intake of caffeine and alcohol – (clever) – what I find really interesting about coffee and alcohol is that of the inverse relationships.  Caffeine is an ergogenic, in that it is one of the few (legal) substances that can make your sporting performance improve instantly.  Alcohol is a poison, which is one of the few (legal) foodstuffs that can kill you if you consume even relatively small quantities of it.  And it certainly slows you down in the short term.  However, drinking caffeine over time has been correlated with various health problems (and health benefits too but let’s not split hairs!)  And drinking small quantities of alcohol over time has been connected with lowered risk of heart disease.  So, like Malcolm Kendrick, this makes me think that the health problems/benefits of these substances are primarily caused by their effect on stress levels.  Caffeine raises stress levels and alcohol reduces them.  I am sure this is too simplistic but you have to start somewhere…
11. Eat a variety of foods – (not sure) – I have read somewhere that a little challenge to the body’s immune system is a good thing, in that the body fights back and makes itself stronger (I can’t find the reference right now).  However, obviously, at a certain point the challenge becomes too great and damage is inflicted.  So I wonder whether there are benefits to being exposed to low levels of toxins.  I would imagine that it is not possible to assess the levels of toxins correctly without better tools than we have at the moment, however…

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As my friend Sumoman might say: everything that we are told is safe is bad for us and everything we are told is bad for us is safe.  He says that about exercise selection.  The picture as regards healthy eating isn’t quite as clear cut as that but sometimes it isn’t far off…