I’ve been meaning to simplify and broaden the health section of this blog and a friend recently asked about nutrition so it seems like a good time to start. I’ll try skip over the finer points and make separate posts about them later on. This will sort of be the parent directory with general info about how nutrition works.

If you break it down, there’s not that much to know. There are two types of nutrients you can consume:

Macronutrients:

These include carbohydrates, protein and fats. Macronutrients are your body’s fuel sources; they are converted to glucose and shuttled to your cells via insulin. More on that mechanism later.

There’s a bit of a misconception that your body burns these separately. You are always burning all three fuel sources, just at different rates. Fat, as you may have guessed, is burned the slowest. Carbs are burned the quickest as they are in a closer chemical state to glucose/sugars. That one fact will be very helpful if you want to watch your weight – glucose is essentially a type of sugar so anything sweet will always have a lot of carbs. Anything bread, pasta or rice based will also contain a lot of carbs.

Carbohydrates themselves are broken down into two different types: simple and complex. Simple carbs have a higher glycemic index and basically release glucose much faster and in spikes. Complex carbs have a lower glycemic index and are thus healthier. More on this later.

Protein is broken down into amino acids which are essential for muscle repair and growth. Unused amino acids can eventually be converted to glycogen (a more complex level of glucose – think of it as a few glucose molecules combined).

Fat is basically an energy store and contains more calories per gram than the others (fat contains 9 calories per gram whereas carbs and protein contain 4). Keep in mind essentially fatty acids like Omega 3 cannot be produced by your body so you must get them through food.

So what are calories then? A lot of people tout calories as the holy grail of weight gain/loss. Honestly, this annoys me. Calories are just a measurement of energy. True, you require a calorie deficit to lose weight and a calorie surplus to gain weight, but that’s a huge oversimplification of the process. Where are these calories from? Saturated fat? Simple carbs? Again, more on this later.

Micronutrients:

These include everything else you might eat besides the macronutrients. Vitamins are a big group. Calcium, iron and fibre are also important for the more serious body builders.

Usually people don’t measure their micronutrient intake – at least not as much as their macros. Micros are more of a long term thing that can boost your gains/losses a bit. Fibre deficiencies in particular are quite common and can help with absorption. For example, the carbs/sugar in fruit are mainly fructose, which is a simple carb, but due to the micronutrient content of fruit (fibre and vitamins), I would still consider fruit to be a healthy food (as would other nutritionists).

The Glucose-Insulin Mechanism:

All the “more on this later” bits were referring to this section. There’s a lot of study in this field so to be brief, basically glucose is the raw form of energy that all foods are broken down into eventually (at different rates). This glucose will be in your system (blood stream). In response to an elevated glucose level, your body produces insulin which causes cells to consume this glucose.

Diabetes suffers at times require insulin shots because their body is incapable of producing enough insulin on its own, meaning the glucose cannot be absorbed. Overconsumption of sugary stuff is often criticised as causing diabetes because sugary stuff is usually simple carbs and thus your glucose levels spike tremendously and your insulin can’t keep up.

Now there are some interesting points to mention. First, your insulin sensitivity is dependent on your health. People familiar with intermittent fasting and cortisol might skip breakfast for this reason. In short, breakfast can cause a glucose spike which will be responded to by an even greater insulin spike (because the person is healthy). This can cause your glucose levels to drop below what it should be (think overshooting the mark). The insulin aims to return your system to balance but it goes too far, causing you to feel hungry again very quickly. This can lead to overeating, or general discomfort.

Next, what happens to excess macronutrients? All macronutrients will eventually be broken down into glucose. What happens to the excess glucose? Well if it stays in your system long enough and isn’t used, then your body will store it. It does this by converting to glycogen and then eventually into fat (fat being the ultimate energy store). And this is why I get annoyed at people who always preach calories but never consider other factors. Yes, calories are the bottom line but they aren’t the only factor involved.

Consider this: a macro target of 2500 calories per day with a maintenance calorie level of 3000. Technically, if the target is reached, the person should lose weight right? Well they will but let’s consider how other factors can affect the weight loss. Say the person eats all 2500 calories in one sitting, and they’re all simple carbs (i.e. he eats two loafs of white bread). First of all, it’s very unhealthy, I know, but let’s take a look at the mechanism.

Simple carbs means huge glucose spike. Excess glucose will be converted to fat. If all the glucose is converted, then his body will have no more carbs. If his body has no more carbs, he has to break down protein (in a process known as catabolism) and fat for fuel. Good news right? He’ll still lose weight because he’ll burn more calories (3000) than he supplied (2500). Yes, but, fat burns the slowest. So he’ll lose weight but most of it will be loss of muscle. It’s entirely possible that he could actually gain fat while losing weight.

If that makes sense to you, you should realise that while calories are still the bottom line for weight loss, there’s much more to it than just that. This is just a general overview of how nutrition works but hopefully this understanding will help you make more informed decisions.

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