Staunch - read over my posts on digestion. You ain't going catabolic when you sleep and your WPC + MILK will be digesting for much longer than you think. FYI WPC+MILK is MC!
From that link that Big Mick provided -
But as I've outlined on another Thread (
http://ausbb.com/nutrition-diet/1534...-gi-myths.html ), you need to think about things like this - If you are consuming a diet of protein ONLY and the amount of protein you have for the day is 200 grams. Now Whey protein digests the fastest at 10 grams an hour. So if you have your WHOLE day's protein needs just with the Whey Protein, that will take 20 HOURS to digest. Now if you had your 200 grams all from say cooked eggs (they digest at 3 grams per hour) it would take 66+ hours.
Now I'm pretty sure your diet consists of Protein, Carbs, Fats and Fibre from a mixture of WHOLE FOOD and powder, correct? Now each one of the other nutrients listed will SLOW digestion time down and if the are from WHOLE food choices it will be SLOWER again. See where I'm going with this
On a side note, when Whey is mixed with fats, carbs & fibre or there is previous ingested food, it 'digests' in the same way MC or CC does.
So as you can see, you go now where near catabolic when you sleep. But as I've said, if you want to have a shake before bed so you meet your macornutreint need for the day, go for it. You are taking it for that reason and the benefits that meeting your macronutrient requirements.