When you're on the go or just finishing a workout, it's hard to get a "real meal" with proper nutrition.

Celebrtiy trainer Adam Ernster will tell you fats and carbs are easy to find, but the right amount of protein is not. That's precisely why he recommends downing a protein shake as a healthy meal replacement instead of stopping for fast food.

Check out the video above to find out why protein shakes are always a good idea!

Tags: adam ernster, alternative, fast food, healthy, meal, protein, protein shake, video, working out