Proteins are made up of amino acids and are the basic building blocks of your body. Because you tear down muscle each time you work out, especially if you work out on a regular basis, a diet rich in protein is vital to building muscle. Whey protein can also be an important and effective component of a weight-loss plan, and protein can help satisfy your hunger and provide needed nutrients and energy to keep you going throughout the day. Whey protein is a nutritious form of protein that has been isolated from milk whey (the liquid substance that is a by-product of cheese production) and had its fat removed to create a healthy food additive.  Most whey protein by itself is sold in powder form and is easy to use with just a few simple ingredients. Be aware, however, that whey proteins are inferior to egg proteins in both biological value (BV) and protein index. They are also not suitable for lactose intolerant people since they have a very high content of lactose, unlike egg proteins.
Calculating Your Protein Requirements
Obtain a protein requirement chart from an online source or nutrition store. Too much protein in your daily diet can lead to adverse side-effects, and is particularly hard on your kidneys, so a protein chart is an important tool when adding whey protein to your diet.
Calculate how much protein you need, based on your weight. It is recommended that both male and female adults (19–50) consume 8 grams (0.28 oz) of protein for every 20 pounds of bodyweight (0.8 g of protein per kg) per day. For example, a person weighing 155 pounds (70 kg) should get 56 g of protein per day.
In general, speed and strength training athletes should get 1.2–1.7 g of protein per kg of body weight, while an endurance athlete may need more like 1.2–1.4 g of protein per kg of body weight. (To find your weight in kg, divide your weight in pounds by 2.2).
So an athlete weighing 175 lbs. (79 kg) would consume 94.8 g of protein daily to meet the minimum of 1.2 g/kg.
Determine the amount of protein you eat. With the help of a nutritional calculator, calculate how much protein you are getting with each meal and, if necessary, how much protein you consume each week. This will help you determine how much protein you need to supplement your diet with.
There are several online resources for determining the protein content of the foods you eat each day or week. A useful example can be found here.
Find the amount of protein you need to get from supplements. If the amount of protein you should have according to your protein requirement chart is more than you are getting from diet alone, you can make up the difference with whey protein. After figuring out your protein intake with a nutritional calculator, subtract the amount of protein you are getting in your diet from the required amount found on your protein requirement chart. The amount of protein left over is what you can get in supplement form from whey protein.
Additionally, if you are a male who exercises regularly, you may benefit from whey protein supplementation to help you recover from exercise more quickly.
Making a Protein Shake or Smoothie
Use a blender. Combining the ingredients in a blender is the most convenient way to make a shake. Follow the instructions on the whey protein container to measure out the proper amount of whey protein powder and blend with the recommended portion of liquid and any other ingredients until smooth.
If you do not have a blender, you can use an electric mixer, blender bottle, or use a whisk or fork to mix the ingredients in a glass or bowl.
Choose your flavor of whey protein. You can buy whey protein in a variety of flavors, which will affect the taste of your smoothie. Flavors include vanilla, strawberry, blueberry, banana, chocolate, and more.
Mix in fruits or other ingredients. Whey protein shakes can be made with fruits and other ingredients to change the flavor and nutritional content. Many recipes can be found in books and online for various preparations of whey protein shakes. To make it easier to blend or mix fruits into whey protein shakes, add liquids first. Depending on your preference, add between one to two cups of one or more of the following:
Watery fruits, including oranges, pineapple and watermelon
Milk, soy milk, almond milk, coconut milk or other low-fat milks
Add ice cubes. Blended ice cubes will thicken and cool your whey protein shake, giving it the consistency of a smoothie or shake. Alternatively, you can freeze bananas, raspberries and other fruits (or buy them frozen) and add them to the drink. You can even make ice cubes out of milk and use these instead.
Add flavor-enhancing ingredients. Whey protein shakes may benefit from the addition of ingredients that improve the flavor. Add these ingredients to your liking and you will improve your shake's flavor. Some ingredients to consider adding include:
Vanilla, nutmeg, cinnamon
Dried fruit, including raisins, apricots and dates
Chocolate, vanilla, strawberry or other milkshake powders
Using Whey Protein to Build Muscle
Eat a whey protein breakfast. Add 1 scoop of whey protein powder to your breakfast cereal, preferably oatmeal. Mix thoroughly with a spoon and eat immediately. Adding whey protein to food in this way lets you increase protein intake without having to adjust your diet too much.
You can add 1 tbsp. (14.1 g) of peanut butter to this mixture for a little extra protein.
Eat protein before your workout. Drink a whey protein shake 30 minutes before exercising. As you work out, your muscle fibers will be broken down, and your stored carbohydrates (glycogen) will become depleted.  A pre-workout shake will help prevent muscle breakdown and provide more energy.
Eat protein after your workout. You need to feed your muscles as soon as you are done exercising to help your body recover. There is evidence that consuming whey protein immediately after a workout increases protein synthesis and, as a result, strengthens muscles. 
Mix whey protein into your last meal of the day. Sprinkle some whey protein powder on food that is part of your last meal of the day. This keeps amino acids in your body at an elevated level as you sleep, which can also assist with building muscle.
You can also drink whey protein before you go to bed to help prevent the protein breakdown that naturally occurs while you sleep, increasing overnight muscle protein synthesis.
Encouraging Weight Loss With Whey Protein
Determine how much whey protein to incorporate into your diet. There are many diet plans available for those who want to use whey protein for this purpose, but in general it is recommended that you only supplement your diet with whey protein rather than replace meals with whey protein shakes. The benefit of supplementing your diet with whey protein is generally that it will help you feel more full, which may cause you to eat less, thereby encouraging weight loss.
Include whey protein in a low-calorie diet. Whey protein will work best as part of a healthy, balanced diet. 
Be aware that high-protein, low-carb diets can have negative side-effects on your health.  Always aim for a healthy balance.
Supplement your diet with whey protein to encourage weight loss via whey protein shakes. When encouraging weight loss, you will want to include fiber and avoid too much sugar. You can achieve the inclusion of fiber with low sugar by incorporating some fruits and vegetables into your shakes. The following suggestions should help:
Add blueberries or raspberries. Both fruits are high in fiber and low in sugar.
Alternatively, add spinach or cucumber. Both vegetables are high in fiber, and don't taste as strong as some other vegetables, so you can mix them into your shake without making it taste strange.
Avoid using honey, maple syrup, or sugar. These contain high amounts of sugar and will be detrimental to a diet plan. The fruit you add to a smoothie will sweeten it naturally. 
Drink a whey protein shake or smoothie before a meal. A protein shake can satisfy your hunger and give you energy, reducing your cravings for other foods.  One study had people drinking protein shakes before a trip to a buffet, and the people who had whey protein shakes consumed less from the buffet than others.
While it is not recommended, replacing your highest-calorie meal with a shake or smoothie should lead to the quickest weight-loss results. Replacing smaller meals with a whey protein drink will also encourage weight-loss, but at a slower pace. 
Drinking a shake can also reduce post-meal blood glucose and improve insulin levels.