Macronutrients – basics of nutrition

One of the ways to look at food is through the lens of calories. We can also look at food based on composition which has given plenty of success to the followers of the flexible dieting approach which is commonly referred to as IIFYM (if it fits your macros). The main idea is that you have a certain caloric intake which you can split into macronutrients and as long as you are reaching your targets, your food choices become less relevant. In practice, this method of creating a meal plan gives you more flexibility, hence the moniker flexible dieting, because you’re not eliminating “junk” food as long as it fits your macronutrient composition.

Selecting nutrient dense foods over calorie dense foods should be the basis of any healthy diet but that doesn’t mean that you have to suffer and restrict yourself completely and that’s where the flexible dieting approach comes in – it allows high calorie, processed options. As with anything and everything, people take it too far and misapply this approach. Unfortunately, some people understood flexible dieting as the “McDonald’s and pizza every single day diet” which is harmful to their health. The issue arises because of marketing when you show pizza, fries, burgers and pancakes as a part of your regular diet while still being able to achieve decent results. It is obviously possible since a calorie deficit will lead to weight loss, but that’s not a very good justification for eating a single extremely tasty meal every day and then suffering through hunger because there simply is no more room, calorically speaking. To be 100% transparent and honest, I did this too for a while, but with slightly different motivation. I had 6 days of eating in a large deficit where I relied on healthier foods as my calorie sources and then each Saturday I’d film a video of me eating some stupid quantities of food (2 kg of cheesecake, 12 burgers, 13 donuts and so on). It was fun because I got to test myself every week and see if my stomach capacity improved and then if it did I could take on an even crazier challenge. However, I was also trying to prove that a calorie deficit is the primary and the most important reason you lose weight. Anyhow, let’s get back to the topic at hand – macros.

There are two categories of nutrients:

1. Macronutrients – these are nutrients that we consume in larger quantities, usually expressed in grams (macro – big)

2. Micronutrients – there are nutrients we consume in smaller quantities, usually expressed in milligrams. These are vitamins and minerals (micro – small)

In this text we’ll only discuss macros so I am going to kill two birds with one stone and name them as well as give you their caloric values:

1. Fats – 9 calories per gram

2. Carbohydrates – 4 calories per gram

3. Protein – 4 calories per gram

4. Alcohol – 7 calories per gram

The digestive efficiency of a particular nutrient is expressed as a percentage and it represents the degree to which a nutrient is absorbed. Fats have a very high level of efficiency, on average 97% is absorbed (this means that if you eat 100 grams of fat, you’ll absorb 97). Proteins from animal sources also have high efficiency and for them it’s between 90 and 95 percent, while vegan protein sources have an efficiency of around 80%. Carbs vary drastically and are highly dependent on the amount of fiber, but you’re not losing many calories unless we’re talking about absurd fiber intakes.

After you absorb nutrients there are two scenarios – storage or oxidation.

Oxidation is basically using nutrients as fuel. All 4 macronutrients are subject to oxidation which means that protein, fats and carbs can all be used for energy. The process of oxidation happens in your muscles, liver and a couple of other places.

Storage is easier to understand, nutrients are kept in their “warehouses” for later use. Carbohydrates are stored in the form of glycogen in your muscles and liver, the fats are stored in fat cells and sometimes as intramuscular triglycerides. There are some diseases which will cause fat storage in places where it’s not supposed to be stored. In the truest sense of a storage, protein does not have its warehouse. After digestion, amino acids are used to build numerous proteins and hormones. Muscles are, in a way some form of a storage for protein (don’t forget that muscles are mostly composed of water). Alcohol does not have a designated storage.

Now we know what the faith is for the nutrients and we’ll quickly take a look at the relationship of storage and oxidation. The rate of oxidation depends on the total size of the warehouse in comparison to your total body weight. The bigger the warehouse the lower the oxidation rate is. To illustrate, body fat is usually expressed as a percentage of total body weight so a 100 kg person with 15% body fat has 15 kilos of fat. That is a huge warehouse, especially if you use that same person and realize that their carb warehouse is 350-450 grams. The conclusion of this is that a larger intake of fat will not increase fat oxidation, while a larger carb intake will increase the amount of carbs being used for energy.

Protein is less adaptive than carbs, but the important fact to remember is that nearly a half of all protein intake is oxidized in the liver irrespective of quantity. In essence, oxidation of protein will increase with a higher intake, but the adaptation is slower than with carbs which is pretty much instantaneous.

We leave the best for last, alcohol has perfect oxidation because it does not have a warehouse and your body (liver) will do everything in its power to get rid of alcohol. This is because alcohol is metabolically viewed and treated as a poison.

This is just a basic, introductory overview of macros. Each of them will get their separate special attention and treatment (multiple texts per nutrient) so that we can have a better understanding of how our body reacts to food intake.