Dietary Problems

Following on from yesterday's post on food and diet, today I'm going to talk about dietary problems, or what happens if you have too much or too little of any of the essential nutrients. I'm going to go one nutrient at a time, and then add a couple more points at the end about various related topics (food additives, alcohol etc.)

Sugar

Although sugar is not super duper harmful, or at least not as harmful as it was once thought to be, many foods high in sugar lack essential nutrients, so eating too many sugary foods can cause you to gain some deficiencies. Sugar can also aggravate certain illnesses, such as diabetes. Oh, and it probably isn't good for your teeth either.

Fibre

Fibre (which is a polysaccharide carbohydrate) has both soluble and insoluble components. Soluble forms, including pectins and mucilage, can be found in fruit and oat bran, and can help to reduce blood cholesterol or control blood sugar in diabetics. Insoluble fibre, which is mostly cellulose (as I mentioned in the aforementioned Food and Diet post), can be found in wholemeal bread, bran cereals and leafy and stringy vegetables, and is required to prevent disorders of the alimentary canal (which I *think* basically just means all the parts of the body that food passes through when being digested).

Fats

We've probably all had the whole "too much fat is bad" lesson drilled into us. Aside from making you grow fat, why else is fat bad?

Consuming fat may contribute to high blood cholesterol. Animal foods contain the lipid cholesterol. Hence, these saturated fats, which come from pork, lamb, beef, milk, butter, cheese and eggs, cause a rise in blood cholesterol, which can lead to cardiovascular disease such as coronary heart disease, stroke and atherosclerosis (hardening and narrowing of the arteries- yay, I FINALLY found out what 动脉硬化 is translated into English!). Don't get me wrong, though- cholesterol is necessary for the body's cell membranes, for hormones produced by the adrenal glands and for some other purposes, but too much can be a bad thing.

Not all fats are bad, however. Polyunsaturated fats, abundant in vegetable oils, as well as in fish and poultry, can actually lower your blood cholesterol. If you consume fewer saturated fatty acids, and more polyunsaturated fatty acids, your body will synthesise less cholesterol from dietary fat. Hence, if you want to control your blood cholesterol levels, substitute foods with saturated fats for those with polyunsaturated fats.

I should now probably give a quick explanation on what "saturated" and "polyunsaturated" actually mean. As Chemistry students should know, "saturated" means that every carbon atom in the molecule is joined to as many hydrogen atoms as it can handle. "Unsaturated" means that there are double or triple bonds somewhere that could take more hydrogen atoms. Monounsaturated means that there's only one double bond, while polyunsaturated means that there are multiple double bonds. This is all covered in my post on the Basics of Organic Chemistry.

Vitamins and Minerals

Vitamins and minerals are pretty essential for the human body. If you're deficient in something, you could end up with a nasty disease- for example, deficiency in calcium could cause rickets or osteoporosis, a deficiency in iron could cause anaemia, a deficiency in Vitamin C could result in scurvy, and so on. A healthy, balanced diet should contain all of the vitamins and minerals you need, though, so you can relax without having to worry about taking supplements. In fact, some vitamins and minerals can actually have toxic effects if you consume too much (way more than you'd get in your diet, so you can still relax).

Salt

Too much salt can result in high blood pressure (hypertension), which can result in strokes. You don't need much salt in your diet- you're probably getting enough from what you're eating without extra salt. You can reduce intake by choosing less salty foods and by not adding extra salt.

Alcohol

Although a little bit of alcohol has been shown to be beneficial, reducing the risk of heart attacks or strokes, you still shouldn't have too much. It's recommended that everyone has at least 2 alcohol-free days a week. Alcohol produces 29 kJ of energy per gram, which is less energy per gram than fatty acids, but more per gram than proteins or carbohydrates. Hence alcohol can also provide you with extra calories that you may or may not need, and if it's the latter, then you're going to end up with some extra fat. Drinking too much alcohol can also lead to other health problems all over the body: liver cirrhosis, cancers, ulcers, heart disease, high blood pressure, brain damage, foetal alcohol syndrome and so on.

Food Additives

Many processed foods have additives. Additives come in many different varieties and have many different functions, including adding flavour or colour, preserving the food, sweetening it, altering the texture, and so on. Also, there might be other things unintentionally added to the food, such as insecticides. Obviously food regulations on additives and food production are quite strict, but due to consumer concern more and more foods are made with fewer or no additives, as you can see from the many bottles and packages on supermarket shelves proudly declaring themselves to contain "NO ADDED PRESERVATIVES" or "NO ADDITIVES."

Take-away Foods

Why is fast food considered unhealthy? Well, they often have too much of some nutrients, namely saturated fat, and not enough of others, such as fibre and vitamins A and C. Fast food is still okay to eat occasionally, but if you eat it all the time you will probably begin to lack certain nutrients and suffer the ill effects of too much saturated fat (which can result in high cholesterol as I said above).

Other random points to make

The rest of this chapter covers food and the media, as well as eating disorders.

The media is good at providing information about food. It's also very good at providing misinformation about food. Hence just make sure to view everything with a critical eye (and "a pinch of salt"... sorry, couldn't resist slipping a pun in there). Make sure to look at the reliability of the source (i.e. who wrote it, is there any bias involved etc.) and how credible the information is. If the diet in question looks too extreme, it probably is.

Oh and be careful about food labelling. There are some very interesting facts in this book, such as that the word "light" can refer to a food being light in colour and not reduced fat, and that "no added sugar" or "no added salt" just means that they haven't put more salt in than they really need, but there could've been a lot of sugar or salt in there to begin with. Sometimes manufacturers get around food labelling laws by deliberately misspelling words- for example, only products containing fruit can use the word "fruit" in its name, which is why you end up with stuff like Froot Loops, which doesn't contain fruit, but it doesn't have to because they didn't spell it right. (I remember writing "I ate Froot Loops for breakfast" in the "diary" thingy that I had to do back in year 3, and the teacher marked it wrong. Good times...)

Now for eating disorders. This book only covers anorexia and bulimia, though there are others, such as binge eating disorder. "Orthorexia," an obsession with eating the "right" foods, is also considered to be an eating disorder by some, but it hasn't been officially included in the DSM (Diagnostic and Statistical Manual of Mental Disorders) as of yet. Anyway anorexia is an eating disorder characterised by restricted food intake, sometimes to the point where sufferers become extremely thin or even die of starvation. Bulimia, on the other hand, is characterised by binge-eating followed by purging methods to gain control. These purging methods can range from self-induced vomiting to using laxatives, all of which can have consequences for the sufferer's physical health. There are lots and lots of reasons why eating disorders may develop. The media is often blamed but I have an extremely strong hunch that the media is generally not the primary cause for most people, but rather other life stressors. In any case, if you're suffering from an eating disorder, or know someone who is, get help as soon as you're able. After all, life has enough challenges already- you don't need an obsession with food adding to it.

And that's all from me for today! Coming next is some info on how food is digested and absorbed from the body! It looks like quite a long, detailed chapter (with lots of highlighting from the two people who used this book before me), so I might take two days, and not one, to cover this chapter. Anyway, I'll cross that bridge when I come to it. Bye for now!