A complete beginners guide to whey protein, whey protein powder and whey protein shakes, bars and supplements.

When it comes to burning fat and building muscle, protein (and in particular whey protein) is a nutrient that will make or break your results. If you're confused about how much protein you need, which type of protein is best, or when you should eat it, our protein Q&A will help you separate protein fact from protein fiction.

How much protein do I need?

The UK Food Standards Agency recommends that adults take in around 55 grams of protein per day. However, studies show that regular exercise increases your need for protein, which means that active people need a lot more. For best results, most experts recommend that you consume around 2 grams of protein per kilogram of bodyweight. To work out how much protein your need, multiply your bodyweight in kilograms by two (e.g. an 80kg man would aim for 160 grams of protein per day).

When's the best time to drink a protein shake?

Most experts recommend taking protein shakes in two servings: one an hour or so before you train, and another dose immediately after training to help repair muscle damage and fuel the growth of new muscle tissue. Protein shakes are a great way of getting protein in to your system, and is quickly absorbed by the body. Protein shakes are also a quick and easy way to consume the supplement, making it ideal for people on the go.

Can protein help me lose fat?

Not only does protein help you build muscle, it also plays an important part during a fat loss programme. As well as helping to preserve lean muscle, which is easily lost when you cut back on your calorie intake, protein also helps with appetite control, making it easier for you to stick to your diet.

What happens if I don't eat enough protein?

An occasional low-protein day will not affect muscle growth. But if you don't get enough protein in your diet on a regular basis, then your body starts burning muscle for energy and your progress in the gym will grind to a halt.

What are the best sources of protein?

As far as your body is concerned, there are two different types of amino acids (the building blocks of protein): essential and non-essential. Non-essential amino acids are amino acids that your body can create by itself. Essential amino acids cannot be created, and therefore the only way to get them is through food.

Many foods, including nuts and beans, can provide a good dose of protein. But the best sources are animal proteins like eggs, meat, poultry fish and whey. Animal protein is complete - it contains the right proportions of the essential amino acids your body can't make on its own. Vegetable sources are usually low on or missing certain essential amino acids.

What are the benefits of whey protein?

Whey protein is one of the two major proteins found in milk, the other being casein. It's one of the most popular sources of protein with athletes and gym users wanting to burn fat and build muscle, and with very good reason.

• A typical serving of whey protein contains the same amount of protein found in a chicken breast, but is also very low in both fat and carbohydrate.
• A naturally complete protein, whey is often referred to as a "fast" protein for its ability to provide rapid nourishment to muscles.
• Whey protein has a higher biological value than many foods, including fish, beef and soya. This means that more of the protein is actually used by your body.
• Whey protein contains high levels of essential amino acids and BCAAs, both of which play a vital role in fuelling muscle growth.
• Whey protein is also naturally high in the amino acids glutamine and leucine, which help with muscle repair and recovery after a tough workout