The Thermogenic Effect of Food: What It Is and Why It Matters
When we think about metabolism and how our bodies use energy, most people focus on exercise and activity levels. But did you know that your body actually burns calories just by digesting the food you eat? This process is known as the Thermogenic Effect of Food (TEF).
TEF refers to the energy your body expends to digest, absorb, and metabolize nutrients. In simple terms, it’s the cost of processing your meals. Every time you eat, your body has to work to break that food down—and different foods require different amounts of energy to process. TEF typically accounts for about 5-15% of your total daily energy expenditure, and understanding how it works can help you make more informed nutrition choices to support your goals.
Let’s take a closer look at how each macronutrient—protein, carbohydrates, and fats—plays a role in TEF and overall health. You’ll also see what happens when you don’t ingest enough of a certain nutrient. This is simply shared to discourage an “all or nothing” approach.
Protein: The High Burner
Thermogenic Effect:
Protein has the highest thermogenic effect of all the macronutrients. Roughly 20-30% of the calories consumed from protein are used in the process of digestion. So if you eat 100 calories of chicken, your body might burn up to 30 of those calories just breaking it down.
Why It’s Beneficial:
Helps build and repair muscle tissue
Keeps you feeling fuller for longer
Supports immune function, enzymes, and hormone production
What Happens If You Don’t Get Enough:
You may experience muscle loss, especially during weight loss or aging
Slower recovery from workouts or injuries
Increased hunger and less satiety throughout the day
Carbohydrates: The Middle Ground
Thermogenic Effect:
Carbs have a moderate thermogenic effect, with about 5-10% of their energy burned during digestion. That means 100 calories of carbs will cost your body 5–10 calories to process.
Why They’re Beneficial:
Your body’s preferred energy source, especially for the brain and during intense exercise
Help replenish glycogen stores after workouts
Support hormonal balance and mood regulation
What Happens If You Don’t Get Enough:
You may feel low on energy, especially during physical activity
Mental fog and difficulty focusing
Poor recovery and reduced performance in workouts
Fats: The Efficient Fuel
Thermogenic Effect:
Fat has the lowest thermogenic effect, with only 0-3% of its calories burned during digestion. It’s metabolically efficient, which means it takes very little effort for your body to store it.
Why They’re Beneficial:
Critical for brain health and hormone production
Help with absorption of fat-soluble vitamins (A, D, E, K)
Support healthy cell function and anti-inflammatory responses
What Happens If You Don’t Get Enough:
Hormonal imbalances, including menstrual irregularities in women
Poor absorption of essential nutrients
Dry skin, joint discomfort, and brain fog
Putting It All Together: Balance is Key
While protein has the highest thermogenic effect and can slightly boost your metabolism, each macronutrient plays a unique and necessary role in your overall health. Focusing too heavily on one at the expense of others can backfire, leading to nutrient imbalances, poor energy levels, and suboptimal performance in your daily life.
Balanced eating—meaning a consistent intake of quality protein, smart carbohydrates, and healthy fats—allows your body to run efficiently. Depending on your goals, you can “tilt” the macronutrient balance slightly (e.g., more protein for muscle gain or more carbs for endurance), but the foundation of a well-rounded diet should remain intact.
In the long term, understanding the thermogenic impact of your food isn’t just about burning a few extra calories. It’s about feeding your body in a way that promotes sustainable energy, performance, and health. Instead of jumping between fad diets, build your plate with purpose—and let your metabolism do the work it was designed to do.
Want help building a nutrition plan that supports your goals and works with your lifestyle? Reach out and let’s talk about how to fuel your body smarter.