My new workout schedule consists of 3 days HIIT, and 3 days of weight training on my HIIT off-days. I'm basically trying to burn fat while keeping the muscle I have (maybe gain some too?). I was wondering if I should drink whey protein after weight lifting. Would that help to get rid of fat?
If you want to develop lean muscle tailor your workout. As for recovery... it is the same for any workout... you have to feed the muscles. Whey is good, but only 25G to 45G will get digested per hour as the protein breaksdown. Whey is a "fast-acting" protein. So a small Whey shake immediately after a workout is recommended... and 30 min's later either consume 1-2 cans of tunafish, 1-2 8oz grilled chicken breast, or a combination protein shake with "egg protein" or albumin... this will provide protein for several hours why you are "catabolic" or recovering. Now... what they don't tell you is that you need carbs to transport the protein effectively, so with your protein "meal", have a cup of brown rice or wheat pasta or low sugar peanut butter on a slice of wheat bread.
Good to note that it is next to impossible to not lose muscle while losing fat. The first thing your metabolism grabs for energy is protein, ie red muscle. The steps required to breakdown fat into energy usable form is complex and requires extended durations of cardiovascular workout. If you're interested, google search glycolysis or Kreb's cycle... the human body at a molecular level is fascinating.