Wednesday, April 16, 2014
Fun With Nutrition - The Carbohydrates
First, though, I do want to talk about the much-maligned carbohydrates, the nutrient most fashionable to avoid before we all found out about trans fats. Like most fashions, these things go in cycles, and I'm finding more and more people who are returning to the habit of avoiding carbohydrates in their diet.
Like I talked about before, the human body requires a certain number of calories per day to be a living human body and a certain amount more to maintain weight. Fats are by far the most energy-dense foods at about 37 kilojoules per gram, which doesn't mean much to you until I convert it to dietary calories (9 kcal/gram).
Now, you might think that a high-fat, high-protein diet could avoid carbs completely and meet your dietary requirements, and you'd have the peculiar-sounding but very common quality of being both right and wrong in the same motion. The Atkins Diet worked by replacing carbs with all the fats and protein that the dieter could want. And it worked, because your calories were far below what your body wanted and so you entered the various metabolic states where your body ate itself - first your lipids, then your proteins.
This was essentially a way of starving yourself safely, which I suppose can be said of all diet-only weightloss methods, but nonetheless it was (and still is) a popular one.
However, through much of human history, and indeed today, the only way to produce enough food that everyone in a given society was getting enough calories without everyone being farmers was to rely to some extent on carbohydrates. This was why we have the phrase daily bread and the Irish Potato Famine was a big deal and why most of Asia has such a heavy culinary reliance on rice.
Carbohydrates are a class of organic compounds (like most of the nutrients, but not all) that have the particular property of being entirely composed of hydrogen, oxygen, and carbon, not at all unlike fossil fuels. They typically, but not always, have a formula that satisfies the condition Cm(H2O)n, which doesn't mean much to most of you but to me it tells me that if you oxidize your average carbohydrate in the presence of gaseous oxygen your waste products will be Carbon Dioxide and Water, probably vapour if you're doing pure combustion.
Carbohydrates are important in the diet because after fat and ethanol (the alcohol which is least toxic and therefore humanity's overwhelming drug of choice after caffeine) they have the greatest energy density per gram, about the same as proteins. The difference is that carbohydrates are both easier for your body to digest (and therefore preferred in dietary terms), and also easier for humans to produce (which is why we have amber waves of grain instead of palamino waves of beef).
These two factors mean that you're going to see a lot of carbohydrates in your diet. Carbohydrates are your sugars and your starches and the distinction is that the sugars have simple molecular structures while the starches are complex. Both are important and both must be moderated but as a general rule is that 55%-75% of your caloric intake comes from carbohydrates, though the WHO recommends that no more than 10% of the same intake of food energy come from sugars.
So, big bowl of pasta, good, drinking a two-litre bottle of root beer all by yourself on a thrice-weekly basis, bad.
Now, studies on carbohydrate restricted diets are far from extensive and really, to make conclusive statements the one or the other on whether or not cutting the carbs out of your diet is good or bad for you is, at this point, more opinion than science, but I can tell you that your options for foods will be broader and your task of balancing the other essential nutrients easier if you leave the carbs on the table. Having said that, the carbohydrates themselves are not essential nutrients - the few that are used to do things in the body other than catabolysis can be built from amino acids, which your body will do in like, an eyeblink, without you even needing to realize you're doing it.
By the way, while this has nothing to do with the root question of carbohydrates I will be releasing, along with the next post, a fancy-pants excel spreadsheet that first calculates your roughly-specific nutritional needs and then allows you to track them. The first edition will require some ability to research food contents but if it is sufficiently popular I may release a second edition with a database of common foods already loaded in.