Six science-approved ways to lose weight by eating more

Think building muscle rather than lose weight and you'll probably do both. Photo / Getty Images

Losing weight is one thing, but not if it comes at the expense of muscle loss. So it makes sense to wonder - is it actually possible to achieve fat loss while maintaining muscle mass? Surprisingly, the answer is yes - but it does involve a smart approach to fitness and nutrition.

A lot of the time, when people lose weight, they wind up with a lot less muscle than they started out with. Why? Weight loss requires an energy (calorie) deficit and muscle building requires an energy surplus. To implement a calorie deficit, you need to either eat fewer calories or burn more calories through exercise, or do a combination of the two.

However, while eating less is necessary for losing overall body mass, this calorie deficit is counter-productive for building muscle at the same time. What's more, if a person is restricting carbohydrates, then fats (in the form of ketones) and proteins will be used for energy instead, therefore won't be available for muscle repair and growth.

So, how can you achieve both goals? These six science-backed strategies will help.

1. Don't overly restrict

Drastic changes in calories will not only sabotage your workout efforts, but will ultimately slow your metabolism, partly due to the loss in muscle that comes when you drop overall body weight. And since muscle is the greatest determiner of your metabolic rate, this muscle loss may largely explain why so many people struggle to keep weight off once they lose it.

To prevent this, your food intake should never dip below your "basal" metabolic requirements, which is the minimum number of calories your body uses to keep all its systems functioning correctly. There are a plethora of online tools that can help you calculate your basal metabolic rate (BMR). While their accuracy is debatable, they will give you a basic understanding.

2. Protein is key

Protein needs are based on age, activity, sex and whether you are breastfeeding or pregnant. However, most authorities recommend around 0.75-0.84g per kilogram of body weight, but many round it up to 1g per kg to keep things simple. For example, if you weigh 75kg, you would need roughly 75g of protein per day. But, in order to preserve lean muscle tissue, adjusting your protein intake slightly is an important piece of the puzzle.

"Achieving a protein intake of approximately 1.3-1.6 grams per kilogram of body weight, or aim for at least 20g of protein in every meal and snack across the day where possible," adds Dr Jackson Fyfe from the School of Exercise and Nutrition Sciences at Deakin University.

"Consuming a slightly greater amount of protein than what is required to meet your energy needs will ensure you have spare to sustain or even build muscle."

So for that same 75kg person, that's a protein intake of roughly 97g — 120g per day. This can be achieved by including protein-rich foods as part of a calorie-controlled eating plan, such as eating a couple of eggs (12g protein), a cheese sandwich (35g protein), glass of milk (10g protein), two handfuls of nuts (12g protein), 1 cup of Greek yoghurt, and 150g steak (40g protein). Pretty easy to do.

3. Focus on strength

On top of adjusting dietary protein intake, performing regular resistance-type exercises (eg push-ups, squats, lunges, or lifting weights), two to three times a week will help burn calories, but more importantly help to maintain existing muscle tone and build more muscle.

4. High vs. low

For the fat loss side of things, balance your strength training with cardio-type activity to help you burn body fat and calories. However, it's best to keep your cardio sessions short and sweet.

"Minimising the total volume (ie. duration and frequency) of endurance training is best," adds Fyfe.

If you're going to perform cardio training, focus on high-intensity interval training (HIIT). This type of cardio involves short bursts of intense exercise with intermittent rest periods. These workouts will maximise fat burn post-exercise.

5. Have a break

Muscle needs time to repair and grow after a workout. Neglecting to give your muscles enough time to recover means they will not get bigger or stronger. At least 48 hours between sessions is a good rule of thumb.

6. Switch it up

Over time, your body gets used to certain exercises and movements, which is why it's important to mix it up in order to make continual gains and help you push past a training plateau. Increase the speed at which you move, modify rest periods, or recruit different muscle groups, such as switching from isolated exercises (eg bicep curls) to compound movements (eg bicep curls with squats). Once your body is confronted with a new challenge, it will use up more energy to conquer it.