Post Workout Protein
Protein is the most important macronutrient that you consume every day and it is the building block for your body. Consuming enough protein on a daily basis from whole foods can be a challenge for most so having whey protein as a post-workout shake can help supplement your diet and contribute to the success of your goals.

Performance Reasons - You're breaking down your muscles when training so the faster you can repair them the better. Whey Protein is a fast digestive protein that speeds up the recovery process and keeps you performing day after day.
Aesthetics Reasons - Fat loss and weight loss are two different things. It sounds obvious but fat loss is losing fat and weight loss is losing weight, which can be fat, water, muscle, etc. To ensure you're losing fat and building lean muscle mass, adequate amounts of protein are necessary.
Longevity Reasons - Aging is inevitable. As you age, your muscle mass decreases so consuming more protein can help you age with strength instead of becoming weak and frail.
You can consume enough protein from whole foods but for the reasons above, I take Phormula-1 Whey Protein right after every single workout. I would never recommend something I don't take myself but I believe in what the brand stands for and it's the best tasting and highest quality protein.
My favorite flavor is Mint Chocolate Cookie but what's great is 1st Phorm offers a 110% money-back guarantee if you're unhappy with your flavor or purchase. So zero risk to you. They also have plant-based as an option if that is your thing. Investing in yourself is the best investment you can make.