Have you heard somebody say something along these lines or have thought this yourself: “I can't eat that it has too much fat” or “ I’m cutting out carbs because they have too many calories”. If so, please raise your hand (you don't have to if you’re in public, that might be a little weird). There is a common misconception that fats and carbohydrates are unhealthy for you and should be avoided at all costs if you’re trying to lose weight. This quite simply isn't the case. As a matter of fact, carbohydrates and fats, along with proteins, are necessary for you to live a happy, healthy life.
Now before we continue, no, this does not mean you can crack open a can of Crisco and go to town. It simply means that you need carbohydrates, fats, and proteins as they are your macronutrients; a substance that is required for an organism to function normally. All three have different properties that distinguish themselves from each other but are majorly important. For example fats are needed in order to digest fat soluble vitamins A, D E, and K, carbohydrates are the body's preferred source of energy, and proteins are crucial to the creation of enzymes and antibodies as well as repairing structural components within the body. Despite their differences they all share one common purpose: They all get broken down to ATP to fuel our body.
However, just like before, there are some major differences that differentiate them from each
other. As I stated earlier, carbohydrates are the preferred energy source of our body and there is a good reason for this: Carbohydrates provide us with energy...FAST. When we start exercising or doing any type of strenuous activity, our body depletes its stores of ATP, and needs to produce more. The metabolic process that breaks down carbohydrates is the fastest acting in the body, which means that during your quick bouts of exercise (100m sprints, weightlifting, etc…) it is carbohydrates that are providing your body with energy. However, as we continue to work, this breakdown of carbohydrates cannot sustain your body. This is where fats come in.
Comparing fats to carbohydrates, you get a whole lot more bang for your buck from fats
than from carbohydrates when we look at the ATP they provide, but there's a catch. The
metabolic process that breaks down fats to ATP takes a while to start providing the body with
ATP. So it's not until we start working for these longer durations that we start to see the energy production from carbohydrates decrease, and as duration increases, energy levels provided by fat will increase. This is why when most people try to lose weight, the first recommendation is doing steady state cardio: the fat reserves in our body are mobilized as a source of fuel, and therefore they will be used up.
So where does protein come in? Well, unless you are quite literally dying of starvation or
intensely fasting, our body doesn't utilize protein as a fuel source. This is because they are far too important to so many different functions within the human body to use as a fuel source when there are fats and carbohydrates that the body could use. This would be the equivalent of burning your heirlooms to heat your house instead of turning on the heat.
Now obviously, there are some pointers we have to keep in mind. First, as stated above,
fats and carbohydrates provide a lot of energy, but if the body does not utilize said energy, they will be stored in the body for future use: this is your adipose tissue or what most people call their “fat”. This is why it is important to exercise while also understanding the role that these macronutrients play. For example, long distance runners or athletes could benefit from higher fat intakes compared to a weightlifter, while a weightlifter could benefit from more carbs in a diet, and both could benefit from increased protein intake to spur the recovery of the body post exercise.
This has been a very broad overview into macronutrients as the deeper you go down the rabbit hole, there are more aspects you can talk about (and the longer these blog posts get) but if you have time I would highly recommend doing some research yourself, or speak with one of The GYM trainers for some additional insight!
Personal Trainer, The GYM @ Norton
B.S. in Exercise Science