IIFYM Part 1 - What are macronutrients?

IIFYM – If it fits in your macros

Macros – Your daily calorie intake broken down into the macronutrients, protein/carbohydrates/fats

To begin with here is a brief explanation of macronutrients and how they are metabolised.

Protein – 4kcal per gram – used to build/repair muscle and provide essential amino acids

Protein provides the body with amino acids that are used for a large array of bodily functions, one of note being the repair/building of muscle. Some amino acids however can metabolise to energy but this is only used in situations of low carbohydrate/fat availability.

This means you can pretty much eat as much protein as you want and I advise you to do so also. Not only does it have a great satiety value but it'll also retain lean muscle mass far better than any other macro nutrient when it comes to dieting. Protein itself cannot metabolise to fat, the excess protein is simply excreted as CO2 and urea.

Carbohydrates – 4kcal per gram – primary energy source

The most confused macronutrient of them all, one that people cower in fear at the thought of eating with such phrases as 'no carbs before marbs' being thrown around. Carbs are the body's primary source of energy. The media likes to advise you to eat complex carbs over simple carbs, but in terms of caloric value it makes absolutely no difference at all, if the calories are the same you will not start losing weight by eating brown bread over white bread.

The metabolism of carbohydrates is quite simple, after digestion the blood sugar levels will rise causing insulin to be released. The insulin will either transport the glucose in the blood to the cells that need it immediately for energy, or to muscle cells or the liver to be stored as glycogen*. If there is too much glucose needing to be stored, lipogenesis takes place and the carbohydrate is converted and stored in fat cells, i.e. fat gain.

Fats (lipids) – 9kcal per gram – energy/fatty acid source

Fats are the most dense source of energy. The fatty acids that are provided by fats are essential to many bodily functions. One of note being the production of essential hormones such as testosterone, thus having a low fat diet is associated with poor mood, low libido and depression. Stored fat will be used as a source of energy when rapid energy consumption is not required or is unobtainable due to low glycogen saturation levels.

When fat is consumed it is sent to the liver where it is processed (lipogenesis) and released into the blood stream as triglycerides. Your fat cells will happily store the triglycerides until your body needs them.

Where does IIFYM come in?

IIFYM is essentially a form of portion control that lets you eat the kind of foods you want, when you want, how you want. When it comes to losing weight the only essential factor is calories in vs calories out, there is no other factor that comes into it. If you are not losing weight, you are eating too much, plain and simple. The most common reason for not losing weight this way is simply delusion and the inability to correctly count portion sizes.

The second part of this article will address fad diets, why they don't work and how to incorperate IIFYM into your lifestyle.

*Beware of overconsuming fructose, while this is not a huge issue in the UK and nor is it an issue with eating actual fruit because of the low fructose volume. Low quality sauces/sweets tend to be manufactured with high fructose corn syrup (HFCS). Fructose is processed in the liver and stored there, if the liver is full it will undergo lipogenesis and go directly to fat cells. This is not a problem with eating 5-10 pieces of fruit but when you're eating high HFCS products it will become a source of rapid weight gain. So beware when buying 20p bottles of ketchup and sweets that aren't a main brand!