Does collagen peptides break a fast?

One unflavoured collagen peptide label lists about 70 kcal and 18 g of protein per 20 g serving. That is about 35 kcal and 9 g of protein in each 10 g scoop. Scoop sizes differ between brands, and flavoured collagen drinks or creamers can add sugar and fat.

The site sorts answers by four goals of its own. One scoop is grey for weight loss, as it sits under the 50-calorie rule of thumb, a rough guide with no official status. Two scoops, at about 70 kcal, pass it. Blood sugar is grey, because collagen has little sugar and protein foods can raise insulin. Protein has to be digested, so collagen breaks gut rest. Lab and animal studies link amino acids to mTOR, the sensor that slows autophagy, so collagen breaks autophagy too.

Collagen counts toward daily protein. It has no tryptophan, so it is an incomplete protein. Take it in your eating window, for example in the first coffee or meal that breaks your fast.