Thermic Effect of Food (TEF)
By now you’ve probably heard a lot of people say that what you eat matters. Only most of the time they are referring to the nutritious quality of the food you consume. Although nutrition is extremely important and deserves its own book, I want to take a step back and talk about food in its absolute most basic form. Everyone will have their own variation of exercise and nutrition. But, before we begin to develop our own styles, we must first learn the tried-and-true basics. Therefore, I’ll be talking about what TEF is and why it’s important, as well as how we can use it to our advantage.
What is TEF?
If you’ve previously read my post on total daily energy expenditure (TDEE) then you already know that this part of the TDEE is responsible for approximately 10% - 15% of our energy use. If you have not read that post, here is the link. I strongly recommend you read that before continuing to avoid any confusion… and because you should…plain and simple. It will follow you for the rest of your life.
The thermic effect of food is the amount of energy that is required to fully process the food you eat. From digestion to absorption, up until it is broken down from macromolecules into micro molecules. Let’s say you take a bite of a sandwich which is typically composed of protein, carbohydrates, and fats. When this is consumed your body will digest and break it down from what you saw on your plate into the macromolecules I have just described. Where the science comes in is that each of the three macro molecules have their own biochemical pathway, each requiring a different amount of energy.
Why is TEF important?
The reason why understanding this is important is because what you eat can alter how much energy your body uses in a day, which will then affect your goals. More importantly, this is one of the components of your TDEE that we can actually change directly with our actions. After all, we eat every day right? So it would make sense that we are adequately educated about this in order to further optimize ourselves. I’ll be honest though this is not a one-stop shop method. This is only 10%-15% of your TDEE so don’t expect any miracles. What you could expect is a helping hand towards your goals, and a diet that will offer better nutrition simply by following some of the below principles.
Research studies, three of which I have included in this post, have shown strong evidence that the composition of your meals can impact your TEF and augment your progress towards weight loss and desired body composition. The macro that has the greatest impact on your TEF and requires the most amount of energy by far, is protein. If there is one thing I want you to walk away from all of this, it is the importance of protein in your diet.
How do we optimize TEF to our benefit?
Believe it or not, each type of food that you consume has a level of complexity to it. The general theme in how the TEF will work, is that the greater the complexity of the food you eat is, the harder it will be for your body to process and break it down. A more complex process will require a greater amount of energy by the body. Essentially, you want to focus on foods that are high in protein and complex carbohydrates as these are the foods that will make your body “work.”. You want to pick this over simple carbohydrates and foods high in fats, mainly saturated, if your goal is to optimize TEF.
When your body absorbs protein, carbohydrates, and fats that you consume it begins processing them through 3 different pathways. If you’ve taken biochemistry you will have an idea of the three different paths relating to each macro that is involved in their breakdown. In a separate post on macromolecules I go into depth (but not too much depth) about how these molecules get processed. In short, the pathway protein requires burns about 5x the amount of energy that the pathway of fats require, and carbs are somewhere in the middle. The more complex the carb, the greater the energy requirement.
For you to optimize your TEF it would be in your best interest to build a diet that focuses on a higher protein intake. For an individual who desires to build muscle, one should aim for about 1.6 – 2.2 grams per kilogram, with the higher range being for greater intensity of resistance training. I know…that sounds like a lot, and I had the same reaction about 5 years ago when I got my first trainer. But, it was only when I started to consume more protein that my body changed the way I finally wanted it to.
As for the second best option, complex carbohydrates should be the next pillar of your diet. There are simple carbs such as sugar, sweets…you know, the “best tasting” carbohydrates. And they do have a place in our diet in moderation. After all, we should enjoy our food. Then there are complex carbs that are composed of more branches and links that your body has to work much harder to break down. Think of it this way, imagine taking a twig and trying to break it. Now imagine grabbing ten of those twigs, bunching them together and then trying to break it. One will clearly take more energy. That is the concept behind eating more complex foods overall. Foods like dark leafy greens, brown rice, oats, beans, etc. Search up some lists online and you will find them.
The rest of your diet should fall into place so long as you build it around those two foundations above. More protein over carbs and fats, and more complex carbs over simple carbs. An easy way to do this is to take a cup of whatever carbohydrates you have on your plate, and replace it with a cup of protein. Just like that you’ve increased the complexity of your meal and increased your protein intake, increasing your TEF and muscle synthesis, respectively. Remember, this is only one component of your TDEE so don’t expect miracles. Expect small improvement, and a step in the right direction.
Key Points:
Protein requires the most energy to be processed in the body, followed by carbohydrates, and then triglycerides (fats)
The more complex the food you eat, the greater the energy requirement to break it down, thus increasing your TEF
Consume about 1.6 – 2.2 grams/kg of protein. Tailored to your level of exercise intensity
Simple hack: Replace one cup of the carbs (ideally the simple carbs) with one cup of protein
References (in case some of you think i’m making this up)
· https://pubmed.ncbi.nlm.nih.gov/15466943/