There has been a lot of attention on the importance of timing of protein intake. Most people by now understand that it is important to get high-quality protein in your body after a workout. However, less attention has been paid to the role of protein at other times of the day such as prior to bed. As you sleep you gradually begin to enter into more of a catabolic mode as the night progresses. According to French researchers, you may be able counteract this by consuming the right protein before bed. They gave healthy subjects 30 g of either whey protein or casein protein and made several measures of the anabolic and catabolic effect for 7 hours after the meal. What they found was that whey protein resulted in a rapid increase in blood amino acids and protein synthesis, but it was short-lived. Casein on the other hand resulted in a prolonged increase in blood amino acids that resulted in a 34% reduction in protein breakdown. The net protein balance remained more positive for the casein protein over the 7 hour period. The authors attributed the superior long-lasting effect of casein to the slower absorption rate. The implications of these findings are that the ideal protein shakes before bed would contain a mixture of slow, moderate, and fast absorbing protein sources to even to minimize protein breakdown and promote protein synthesis. Three high quality protein sources with slightly different rates of absorption that should keep you in an anabolic mode through the night are casein, whey, and egg protein.

Boirie Y, Dangin M, Gachon P, Vasson MP, Maubois JL, Beaufrere B. Slow and fast dietary proteins differently modulate postprandial protein accretion. Proc Natl Acad Sci U S A. 1997 Dec 23;94(26):14930-5.