The thermic effect of food is a crucial part of the fat loss conversation. We often talk about calories, hormones, exercise, and sleep, but we don’t talk enough about TEF.
This article will address:
- What is The Thermic Effect of Food?
- Why Thermic Effect of Food is Important for Fat Loss
- The Thermic Effect of Each Macronutrient
- Are all Calories the same?
What is The Thermic Effect of Food?
The thermic effect of food or TEF is the number of calories your body burns through the digestion, absorption, and processing of food.
Roughly 10% of your total daily energy expenditure comes from TEF. The other 90% comes from your basal metabolic rate and physical activity.
Why Thermic Effect of Food is Important for Fat Loss?
Why should you even care about TEF?
To lose fat, you need to sustain a prolonged energy deficit or a calorie deficit. This could never be mentioned too much.
The problem you’re going to run into is satiety. If you don’t feel reasonably full on a low-calorie diet, you’re not going to sustain a low-calorie diet.
Basically, you’re going to end up overeating and not getting lean.
Foods that have a high thermic effect make it easier for your body to maintain a caloric deficit. These foods are more nutritious, higher in volume, and lower in calories.
The Thermic Effect of Each Macro-nutrient
To get the best thermic effect from your macros, you need to keep them balanced. You don’t want to be too deficient in protein, carbs, or fats when dieting.
In the context of a caloric deficit, any kind of macro-nutrient deficiency can lead to:
- Poor training performance
- Bad training recovery
- Muscle loss
- A decline in sleep quality
- A decrease in testosterone levels in men
- Intense hunger pains
- Non-functional hormones
Thermic Effect of Protein
Protein has a thermic effect of 20-30%, which is the highest of all three macro nutrients. It makes sense since protein is the most satiating.
If you’re consuming 125 grams of protein a day, that’s 500 calories. There are 4 calories in a gram of protein (125 x 4 = 500). Of those 500 calories, 100-150 of them will be burned through digestion.
Because protein has such a high TEF, does this mean you should eat as much protein as possible to drop body fat?
No, it does not.
At the end of the day, it’s the caloric deficit that causes fat loss. Eating an absurd amount of protein won’t benefit you if the deficit is not in place.
Based on the scientific literature, you only need 0.7 – 0.8grams of protein per pound of your lean bodyweight.
Once that metric is met, you should fill the remainder of your calories with carbohydrates and fats.
Protein is the most filling macro until you get enough of it. You shouldn’t overconsume protein at the expense of carbs and fats.
Also, make sure you’re consuming quality sources of protein. What a lot of people think is quality protein is really not.
If the protein doesn’t contain all 9 essential amino acids or is complete, you don’t have a quality protein source.
If you don’t know which protein foods to build your diet on, read this article, 11 Best Sources of Protein for Promoting Fat Loss.
Thermic Effect of Carbohydrates
Carbohydrates have the second highest thermic effect with around 5 – 15%. This depends on the kinds of carbs you’re consuming.
Whole grains, fibrous fruits, and vegetables will have a higher thermic effect because they are complex carbs. They take longer to digest, and they’re more micro-nutrient dense.
Simple carbohydrates like refined-white flour products and soda will have the lowest thermic effect. They are fast-digesting and devoid of nutrients. Therefore, they don’t require much energy to break down.
Carbs are just as good as protein at promoting fat loss. They support:
- The drop off of leptin, which is your satiety hormone
- Training performance
- The replenishment of muscle glycogen after an intense workout
- Sleep quality
- Testosterone levels in men
Don’t buy into the hype about carbs being “bad” for you or making you “fat”. It’s a myth.
Truth is what makes you fat is an over-consumption of calories long-term. If you’re consistently eating more food energy than your body burns daily, those excess calories will be stored as fat.
If you want, you can delay your carb intake to a later part of the day. This is NOT to be confused for a low-carb or keto-genetic diet.
This is a strategy used to keep you fuller on an aggressive fat loss program.
For instance, you may wish to lose 2 pounds of body fat per week. This would require a 1,000-calorie daily deficit or a 7,000-calorie weekly deficit.
It’s hard to stay reasonably satiated in a deficit that large. By consuming the bulk of your carbohydrates at night, you will have better satiety on a rapid weight loss plan.
If you want to know more about the advantages of eating most of your carbs at night, give this article a read, Amazing Benefits of Carb Backloading.
Thermic Effect of Fats
Fats have the lowest TEF with around 0-3%. The body doesn’t burn many calories digesting dietary fat.
Does this mean fat isn’t as equally important as protein and carbohydrates?
No, it does not.
Fats are great for:
- Functional hormones
- Making meals taste good
- Maintaining high testosterone levels in men
- Steady-state physical activity
Where fat has the advantage over protein and carbs is insulin control. Fats don’t raise insulin as much as the other 2 macro-nutrients do.
Now, does this mean you should adopt a high-fat or ketogenic diet to keep insulin levels low?
Absolutely not!
Fat is your most calorically dense macro. There are 9 calories in a gram of fat, 4 calories in a gram of carbohydrates, and 4 calories in a gram of protein.
It makes sense to keep fat intake lower than protein and carb intake to control calories.
Insulin is not an inherently bad hormone. People just don’t understand all of what insulin does.
If you want to educate yourself more about this misunderstood hormone, check out this article, How to Stabilize Insulin Levels for Better Fat Loss.
Are All Calories the Same?
Yes, all calories are the same, but context is needed for you to understand why that’s the case.
A calorie is just a unit of energy. They are all the same. However, all sources of calories are not the same.
200 calories of carbs from oatmeal are the exact same as 200 calories of carbs from a donut.
The macronutrient composition of the 2 foods are the same, but the micronutrient composition is different.
200 calories of carbs from oatmeal will have more fiber and other micronutrients. It will also be slower-digesting because it’s a complex carbohydrate.
200 calories of carbs from a donut are empty calories, have very little nutrients, and fast-digesting. It won’t keep you full very long.
People tend to use the thermic effect theory to argue that “all calories are not the same.” They don’t realize there’s a difference between calories and nutrients.
Conclusion
The thermic effect of food theory is important for fat loss, but it’s not to be taken as fat loss science. The caloric deficit is what causes fat loss.
TEF is important to understand when deciding on foods to keep you full on a low-caloric intake.
It should be viewed as a dietary decision-making tool.
Of course, you should also enjoy what you’re eating or else the diet won’t be sustainable for you.
Keep in mind, TEF is just one component of your total daily energy expenditure.
If you want to learn more about the other 2, read this article, 3 Ways Your Body Burns Calories in a Day.