How to Prevent Muscle Loss During Weight Loss

When you are trying to lose weight, wanting rapid results is entirely understandable. When the reading on the scales falls quickly, it can feel as though you are doing everything right.

However, as with many aspects of weight loss, there is a downside: losing weight too quickly can cause a substantial reduction in muscle mass as well as fat.

So, how can you recognise whether you are losing too much muscle, and what can you do to avoid it?

Why is muscle mass important?

Muscle plays a key part in determining metabolic rate – the amount of energy we use while at rest. This is influenced by the proportion of muscle and fat in the body. As muscle is more metabolically active than fat, it burns more calories.

When we diet to reduce weight, we create a calorie deficit, meaning the food we consume does not provide enough energy to meet the body's needs. The body then begins using fat and muscle tissue as fuel.

Losing calorie-burning muscle mass reduces our metabolic rate. This can quickly slow weight loss and affect our capacity to maintain a lower weight over the long term.

How to know if you are losing too much muscle

Unfortunately, tracking changes in muscle mass is not straightforward.

The most precise method is a dual-energy X-ray absorptiometry (DXA) scan, an advanced type of X-ray. These scans are mainly used in clinical settings and research to collect information about weight, body fat, muscle mass and bone density.

Although DEXA is increasingly available at weight-loss clinics and gyms, it is not inexpensive.

There are also numerous "smart" scales for home use which claim to give an accurate measurement of muscle-mass percentage.

Yet the reliability of these scales is uncertain. Researchers found that the scales they tested substantially overestimated or underestimated fat and muscle mass.

Fortunately, three free, scientifically supported signs can indicate that you may be losing too much muscle mass while dieting.

1. You are losing far more weight than expected each week

A large, rapid drop in weight is an early warning that your diet may be too restrictive and that you could be losing excessive muscle.

Fast weight loss – more than 1 kilogram each week – leads to greater muscle-mass loss than gradual weight loss.

Losing weight slowly is better for retaining muscle mass and can also result in greater fat-mass loss.

One study examined people in the obese weight category who followed either a very-low-calorie diet of 500 calories a day for five weeks, or a low-calorie diet of 1,250 calories a day for 12 weeks.

Although both groups lost comparable amounts of weight, those following the very-low-calorie diet of 500 calories a day for five weeks lost significantly more muscle mass.

2. You feel tired and everyday tasks seem harder

It may sound self-evident, but fatigue, sluggishness and difficulty completing physical activities – such as exercising or doing household jobs – are further strong indications that you may be losing muscle.

Research suggests that a reduction in muscle mass can adversely affect the body's physical performance.

3. You are feeling moody

Mood changes, along with anxiety, stress or depression, can also signal muscle-mass loss.

Research into age-related muscle loss indicates that low muscle mass may have a negative effect on mental health and mood. This appears to arise from the connection between low muscle mass and proteins known as neurotrophins, which help to regulate mood and feelings of wellbeing.

What can you do to maintain muscle during weight loss?

Fortunately, there are also three steps you can take to preserve muscle mass while following a calorie-restricted diet for weight loss.

1. Include strength training in your exercise plan

Although a varied exercise programme is important for supporting overall weight loss, muscle-strengthening activity is a reliable way to help limit muscle-mass loss.

A meta-analysis of studies involving older people with obesity found that resistance training could prevent almost 100% of the muscle loss caused by calorie restriction.

Using diet alone to lose weight reduces muscle as well as body fat, slowing your metabolism. It is therefore vital to include enough suitable exercise in your weight-loss plan to retain your muscle-mass stores.

You do not need to go to the gym, however. Bodyweight exercises – including press-ups, pull-ups, planks and air squats – can be just as effective as lifting weights or using strength-training equipment.

Encouragingly, moderate-volume resistance training – three sets of ten repetitions across eight exercises – can be as effective as high-volume training – five sets of ten repetitions across eight exercises – for preserving muscle during a calorie-restricted diet.

2. Eat more protein

Protein-rich foods are essential for building and maintaining muscle mass, and research also indicates that they can help prevent muscle loss while you are following a calorie-restricted diet.

This does not mean only eating protein-containing foods. Meals should be balanced, with a source of protein, a wholegrain carbohydrate and a healthy fat to meet dietary needs. One example is eggs on wholegrain toast with avocado.

3. Make your weight-loss plan slower

When we alter our diet to lose weight, we push the body outside its comfort zone and activate its survival response. The body then works against weight loss by triggering several physiological responses intended to protect body weight and "survive" starvation.

The body's survival mechanisms encourage us to regain lost weight so that we can survive the next period of famine, or dieting. Research indicates that participants regain more than half the weight they lose within two years, and regain more than 80% of lost weight within five years.

A gradual, steady and staged approach to weight loss, however, stops the body from activating weight-defence mechanisms when we attempt to lose weight.

Ultimately, successful long-term weight loss depends on making gradual lifestyle changes that help you establish habits which last a lifetime.

At the Boden Group, Charles Perkins Centre, we are studying the science of obesity and running clinical trials for weight loss. You can register here to express your interest.

Nick Fuller, Charles Perkins Centre Research Program Leader, University of Sydney

This article is republished from The Conversation under a Creative Commons licence. Read the original article.