Carbs or Fats?

What is the better choice for my fat loss? 


By Douglas Pieterse, Co-Founder & Head Personal Trainer
"It may be simple but not always easy"

There is a lot of media hype into cutting out carbohydrates in order to make your life better. In fact, if you cut out carbs not only will you lose weight, but you won’t have any more grey hair, you'll be taller and your sense of humor will be appreciated across all sexes and age groups. 


At the end of the day, if you are in an energy deficit you will end up losing weight (ideally fat). But here is my take on which directions you could adopt, and what might work best for your training style. 


Why Fat?

When you are on a high fat, low carbohydrate diet consistently it will eventually push your body into a state of ketosis, the basis for the Ketogenic Diet. What happens is that the body needs glucose to function, and the brain uses it as a primary fuel source. Efficient muscle protein synthesis happens when you have enough glucose in the system. When you cut out most of your glucose intake the body will use whichever substrates it has available. For example, it may take available protein and go through a process of glycogenesis in order to provide the body with the glucose it needs, or it breaks down fat stores in order to create ketones which act as an alternative. Pretty amazing right?


Another consideration while on the ketogenic diet is that your body will use fat as its main fuel source which allows for a higher oxidative adaptation to training. This is great for long distance type of training or activities that require you to hold your breath for a long time, but sprinting will be another story. As the system is not as efficient at providing the necessary glucose to the muscles when it's needed, there will be a performance drop when it comes to sprints or muscle gain. There can also be some metabolic inflexibility as the body creates muscle insulin resistance in order to keep enough glucose in the blood to fuel the brain. Less glucose for the muscle means less performance. 

Can I have white bread please!

So, what if carbs are your life and cutting them out is just too heartbreaking? No problem, you should remember that the main key is energy balance, so as long as you are not eating more than you need you can still lose weight. Another interesting fact is that it is much harder for the body to convert carbohydrates into fat than you may think. You would need to be eating about 1kg of carbohydrates before the body starts to look at converting it. Fat is much easier to store, which is why when eating carbs and fats together in an energy excess, the body will look to store the fat consumed and run the system off the preferred fuel source of glucose (carbs). 


There are a few other big positives as well. Since your body likes using glucose as a source of energy it would mean a more efficient system for getting glucose where you need it fast. This is great if you are doing a sport that has more intensity to it. Think sprinting, powerlifting and jumping based exercises. Trying to build muscle will also be better facilitated with adequate glucose in the system.  This is all hunky dory, but I suppose there are a few other things to consider as well. 


Carbohydrates have been shown to not only taste good but facilitate the feel-good chemical dopamine to be released in the brain. Now there is a lot of speculation around this but the main one for me is that it tends to have a less satiating effect compared to fat and protein. 


What this means is that it can be easier to overeat with carbohydrates as you end up craving them more but, not feel as full as you would like. A simple way to deal with this could be to consume an adequate amount of protein with the carbs to help keep you feeling full for a longer period of time. 



At the end of the day, there is more than one way to get the results you want by keeping your protein intake adequate and then look to create either an energy deficit, balance or surplus depending on your goals. If you like carbohydrates and it works well for the type of training that you are doing then great, go for it. If you love fat and long runs along the river then again you may have a match made in heaven. But let’s say you love doing the shorter more aggressive workouts and feel that sticking to a low-fat high carb diet will make it easier for you to stay within your food budget then go for that too. Unless you are looking to perform at a higher level then realistically it won’t make a huge difference. Your diet always needs to be sustainable and this only happens when it aligns with your lifestyle and your goals.