The present invention is directed to a liquid heat sterilized enteral composition comprising: a protein source in an amount of 12 to 20% by weight of the composition, the protein source comprising whey protein preferably containing whey protein micelles, and a source of casein, and optionally other proteins. The inventive heat sterilized enteral composition preferably has a cysteine content of at least 1.2 % by weight of the protein source. The present invention is furthermore directed to a process for preparing such a heat sterilized enteral composition comprising protein in an amount of 12 to 20% by weight based on the weight of the composition, said protein comprising whey protein containing whey protein micelles and casein and optionally other proteins. The process comprises the steps of: (i) Providing an aqueous solution of a protein source comprising whey protein containing whey protein micelles and (ii) Adding a protein source containing casein (iii) Optionally performing a homogenization treatment step (iv) Performing a heat treatment step (v) Optionally performing a homogenization treatment step. Finally, the invention concerns the use of a protein source comprising whey protein containing whey protein micelles, a source of casein and optionally other proteins, for preparing an enteral composition and/or for controlling the viscosity of a liquid enteral composition, wherein the enteral composition comprises 12 to 20 weight % total protein. The invention also concerns medical uses and treatments applying or using the inventive heat sterilized enteral composition.La présente invention concerne une composition entérale liquide thermostérilisée comprenant : une source protéique dans une quantité de 12 à 20 % en poids de la composition, la source protéique comprenant une protéine de petit-lait contenant de préférence des micelles de protéines de petit-lait, et une source de caséine, et éventuellement dautres protéines. La composition entérale thermostérilisée de