We all have different fitness goals. Some of us want to slim down, others have a specific fitness or strength target to aim for, and many people simply want to stay active and healthy. However, one very common aim is to lose body fat while also gaining muscle, and this might be harder than you think.


The problem of protein synthesis

The problem lies with how the body works. Muscle is built up by a process called protein synthesis. Essentially, every time you lift weights you’re damaging your muscle cells. Your body creates new ones to replace them, but also adapts to the activity that caused the damage by increasing the number of cells in the affected areas. This is why the more you work out, the bigger your muscles get.

Of course, this process takes energy, and when it comes to the human body that energy is going to come from one place: food. If you’re consuming enough calories, your body will have no problem building up your muscles. However, if you are trying to lose weight, you need to burn more calories than you consume.

This creates what is called a caloric deficit, and when this happens your body does a few different things. One example is that it uses the calories stored in your fat cells for energy, which is how you lose weight. However, it also cuts down on protein synthesis.

This creates a problem: if you’re doing everything you can to gain muscle, you won’t burn any fat, but if you’re focusing on burning fat then your muscles won’t be able to rebuild. So what is the solution?


Avoid the deficit

If you want to cut fat and bulk up – something often referred to as ‘culking’ – then you don’t really want to eat any less than normal. In fact, you probably want to be eating slightly more calories than you need. However, it’s not how much you eat that’s important, but what you eat.

Let’s get the obvious things out of the way first: you need to eat well. No junk food, avoid too many complex carbs and make sure you’re eating plenty of different fruits and vegetables. Opt for wholemeal bread and pasta, and brown rice, wherever possible. Eat at regular times each day, planning in healthy snacks if you find it difficult to go without them between meals.

But the most important part of your diet when cutting fat and building muscle is protein. You should be eating up to one gram of protein per gram of your target body weight each day. So if you want to be a lean 170lbs, that means you should aim for between 120g and 170g of protein per day.

This will speed up your metabolism, which is important. Digesting food accounts for around ten per cent of the calories you burn each day, and this will increase on a high-protein diet. However, you are also providing your body with what it needs to rebuild your muscles.


Hit the gym consistently

As with most aspects of fitness, this requires patience. To cut fat and build muscle, you should be working out about four times a week, and you should be consistent with the exercises you perform. You also need to make sure you have a good, well-structured routine, and not just a few reps of whatever weights you feel like lifting.

For maximum gains, you should focus on compound exercises. These work multiple different muscle groups at the same time, as opposed to isolation exercises, which only work a single one. The classic bicep curl, for example, is no use here as it only works – you guessed it – the bicep.

Squats, deadlifts, standing rows, bench presses and military presses are all good examples of compound exercises. Make sure to look up how to do them properly and safely before starting, or ask a trainer at your gym to help you out.

The aim should be to lift heavy weights for a few reps. Find a weight for each exercise that you can lift for less than six reps; if you can just about do four, that’s perfect. Perform each exercise by completing four sets of four reps each, with about 60 seconds of rest in between each set. If you can complete this, then increase the weight next time.

If you can keep up this diet and exercise plan, you should start to see your fat being replaced by muscle. This will require patience – it might be 12 weeks before you really notice a difference – but it will pay off in the end.