Even if your body burns 25% of protein calories digesting it, you still store or use 75% of them as energy.

We analyzed the available evidence on the net energy yield from dietary protein and found that only one assertion supports the idea that about 75% of protein’s calories are retained, with 25% lost to diet-induced thermogenesis, while 56 studies or assertions refute it. What we’ve found so far leans strongly against this claim. Diet-induced thermogenesis refers to the energy your body uses to digest, absorb, and process food — and for protein, the evidence suggests this cost is much higher than 25%. Many of the refuting studies show that the body expends closer to 20–30% of protein’s calories just on digestion, and in some cases even more, depending on the type of protein and individual metabolism. This means the usable energy from protein is likely lower than 75% — possibly closer to 70% or less in many cases. The single supporting assertion does not align with the broader pattern in the data we’ve reviewed. Our current analysis shows that the commonly cited 75% net yield figure may be outdated or oversimplified. For someone tracking calories or managing body composition, this suggests that protein may contribute fewer usable calories than often assumed, but the exact number varies by context. More research is needed to pin down precise values across different populations and protein sources.