The reason why you are hungry after a workout all starts with how you prep for your workout.
Do you believe that you should exercise BEFORE you eat anything ?
That contributes to your hunger.
Do you wait over an hour after working out to finally eat something?
That also contributes to your hunger.
When you workout you are burning calories and using up lots of energy. In order to fuel your body to perform at it's peak during your workouts it is imperative that you try to eat something before your workout. This will impact your performance and your hunger level when you finish. I know there is that age old belief that talks about working out on an empty stomach so you can start the day with a good sized deficit, but trust me, you will feel better if you start your day with little something in your stomach before your workout. Personally, I cannot stomach eating too much, but a little is better than nothing. Think 1 cup of Multigrain cheerios, a handful of almonds, or 1 egg.
Now for after the workout when you feel like you could eat just about ANYTHING that comes in your path. Before you grab your car keys and run to the nearest McDonald's, grab a banana. This is probably one of the best post-workout snacks that you can eat. Since I am following a low-carb plan right now, I make sure that I have a protein shake within 1 hour of working out. The protein not only helps repair your muscles after you workout, but it will fill you up. When you workout you are burning calories and using up lots of energy. The calories need to be replenished somewhat to keep you going throughout the day AND keep your metabolism running strong.
My protein shake doesn't look as lovely as the one to your left when I am leaving the gym, but on the weekends, I try to make it more like a smoothie. Now, if you are worried about the taste, please don't. I purchase my generic gym brand (Xsport Fitness), but another yummy brand is Optimum Nutrition, who I actually heard makes the Xsport brand, so the taste should be similar. I prefer the chocolate powder because I can mix 3 scoops (60g of protein!) with just water and it tastes great. I am not a fan of the vanilla unless I mix it with milk instead.
When I am at the gym, they actually have a smoothie bar, so I get a 32oz chocolate protein shake made with peanut butter and water. This honestly keeps me full until lunch time. When I am home I substitute regular peanut butter for PB2 (powdered peanut butter) to save me some calories and added fats.
Hope this helps more! Have you tried anything else to curb your appetite after exercise?