Whey and casein are both milk proteins, with whey the faster digesting and casein taking a longer amount of time to be absorbed. This separates them into unique usage occasions for different aspects of workout recovery. A study published in The Journal of Nutrition suggests digestion rate isn’t the only area of differentiation between these dairy proteins.

Researchers incorporated each protein as 15% of the calories in a high-fat meal served to 10 healthy overweight men. Blood levels of glucose, amino acids and insulin weren’t very different after the meal, but post-meal triglycerides were reduced by around 20% with casein. The effect lasted for 6 hours.

True Strength Moment: It turns out that casein’s lower acidity compared to whey helps separate more protein from fat. With whey, protein tends to be suspended in fat globules known as chylomicrons which transport nutrients throughout the body.