When trying to lose weight, it’s natural to want to see quick results. So when the number on the scales drops rapidly, it seems like we’re on the right track.

But as with many things related to weight loss, there’s a flip side: rapid weight loss can result in a significant loss of muscle mass, as well as fat.

So how you can tell if you’re losing too much muscle and what can you do to prevent it?

Why does muscle mass matter?

Muscle is an important factor in determining our metabolic rate: how much energy we burn at rest. This is determined by how much muscle and fat we have. Muscle is more metabolically active than fat, meaning it burns more calories.

When we diet to lose weight, we create a calorie deficit, where our bodies don’t get enough energy from the food we eat to meet our energy needs. Our bodies start breaking down our fat and muscle tissue for fuel.

A decrease in calorie-burning muscle mass slows our metabolism. This quickly slows the rate at which we lose weight and impacts our ability to maintain our weight long term.

How to tell you’re losing too much muscle

Unfortunately, measuring changes in muscle mass is not easy.

The most accurate tool is an enhanced form of X-ray called a dual-energy X-ray absorptiometry (DXA) scan. The scan is primarily used in medicine and research to capture data on weight, body fat, muscle mass and bone density.

But while DEXA is becoming more readily available at weight-loss clinics and gyms, it’s not cheap.

There are also many “smart” scales available for at home use that promise to provide an accurate reading of muscle mass percentage.

However, the accuracy of these scales is questionable. Researchers found the scales tested massively over- or under-estimated fat and muscle mass.

Fortunately, there are three free but scientifically backed signs you may be losing too much muscle mass when you’re dieting.

1. You’re losing much more weight than expected each week

Losing a lot of weight rapidly is one of the early signs that your diet is too extreme and you’re losing too much muscle.

Rapid weight loss (of more than 1 kilogram per week) results in greater muscle mass loss than slow weight loss.

Slow weight loss better preserves muscle mass and often has the added benefit of greater fat mass loss.

One study compared people in the obese weight category who followed either a very low-calorie diet (500 calories per day) for five weeks or a low-calorie diet (1,250 calories per day) for 12 weeks. While both groups lost similar amounts of weight, participants following the very low-calorie diet (500 calories per day) for five weeks lost significantly more muscle mass.

2. You’re feeling tired and things feel more difficult

It sounds obvious, but feeling tired, sluggish and finding it hard to complete physical activities, such as working out or doing jobs around the house, is another strong signal you’re losing muscle.

Research shows a decrease in muscle mass may negatively impact your body’s physical performance.

3. You’re feeling moody

Mood swings and feeling anxious, stressed or depressed may also be signs you’re losing muscle mass.

Research on muscle loss due to ageing suggests low levels of muscle mass can negatively impact mental health and mood. This seems to stem from the relationship between low muscle mass and proteins called neurotrophins, which help regulate mood and feelings of wellbeing.

So how you can do to maintain muscle during weight loss?

Fortunately, there are also three actions you can take to maintain muscle mass when you’re following a calorie-restricted diet to lose weight.

1. Incorporate strength training into your exercise plan

While a broad exercise program is important to support overall weight loss, strength-building exercises are a surefire way to help prevent the loss of muscle mass. A meta-analysis of studies of older people with obesity found resistance training was able to prevent almost 100% of muscle loss from calorie restriction.

Relying on diet alone to lose weight will reduce muscle along with body fat, slowing your metabolism. So it’s essential to make sure you’ve incorporated sufficient and appropriate exercise into your weight-loss plan to hold onto your muscle mass stores.

But you don’t need to hit the gym. Exercises using body weight – such as push-ups, pull-ups, planks and air squats – are just as effective as lifting weights and using strength-building equipment.

Encouragingly, moderate-volume resistance training (three sets of ten repetitions for eight exercises) can be as effective as high-volume training (five sets of ten repetitions for eight exercises) for maintaining muscle when you’re following a calorie-restricted diet.

2. Eat more protein

Foods high in protein play an essential role in building and maintaining muscle mass, but research also shows these foods help prevent muscle loss when you’re following a calorie-restricted diet.

But this doesn’t mean just eating foods with protein. Meals need to be balanced and include a source of protein, wholegrain carb and healthy fat to meet our dietary needs. For example, eggs on wholegrain toast with avocado.

3. Slow your weight loss plan down

When we change our diet to lose weight, we take our body out of its comfort zone and trigger its survival response. It then counteracts weight loss, triggering several physiological responses to defend our body weight and “survive” starvation.

Our body’s survival mechanisms want us to regain lost weight to ensure we survive the next period of famine (dieting). Research shows that more than half of the weight lost by participants is regained within two years, and more than 80% of lost weight is regained within five years.

However, a slow and steady, stepped approach to weight loss, prevents our bodies from activating defence mechanisms to defend our weight when we try to lose weight.

Ultimately, losing weight long-term comes down to making gradual changes to your lifestyle to ensure you form habits that 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 license. Read the original article.

It’s that time of year when many people are getting started on their resolutions for the year ahead. Doing more physical activity is a popular and worthwhile goal.

If you’re hoping to be more active in 2024, perhaps you’ve invested in an activity tracker, or you’re considering buying one.

But what are the benefits of activity trackers? And will a basic tracker do the trick, or do you need a fancy one with lots of features? Let’s take a look.

Why use an activity tracker?

One of the most powerful predictors for being active is whether or not you are monitoring how active you are.

Most people have a vague idea of how active they are, but this is inaccurate a lot of the time. Once people consciously start to keep track of how much activity they do, they often realise it’s less than what they thought, and this motivates them to be more active.

You can self-monitor without an activity tracker (just by writing down what you do), but this method is hard to keep up in the long run and it’s also a lot less accurate compared to devices that track your every move 24/7.

By tracking steps or “activity minutes” you can ascertain whether or not you are meeting the physical activity guidelines (150 minutes of moderate to vigorous physical activity per week).

It also allows you to track how you’re progressing with any personal activity goals, and view your progress over time. All this would be difficult without an activity tracker.

Research has shown the most popular brands of activity trackers are generally reliable when it comes to tracking basic measures such as steps and activity minutes.

But wait, there’s more

Many activity trackers on the market nowadays track a range of other measures which their manufacturers promote as important in monitoring health and fitness. But is this really the case? Let’s look at some of these.

Resting heart rate

This is your heart rate at rest, which is normally somewhere between 60 and 100 beats per minute. Your resting heart rate will gradually go down as you become fitter, especially if you’re doing a lot of high-intensity exercise. Your risk of dying of any cause (all-cause mortality) is much lower when you have a low resting heart rate.

So, it is useful to keep an eye on your resting heart rate. Activity trackers are pretty good at tracking it, but you can also easily measure your heart rate by monitoring your pulse and using a stopwatch.

Heart rate during exercise

Activity trackers will also measure your heart rate when you’re active. To improve fitness efficiently, professional athletes focus on having their heart rate in certain “zones” when they’re exercising – so knowing their heart rate during exercise is important.

But if you just want to be more active and healthier, without a specific training goal in mind, you can exercise at a level that feels good to you and not worry about your heart rate during activity. The most important thing is that you’re being active.

Also, a dedicated heart rate monitor with a strap around your chest will do a much better job at measuring your actual heart rate compared to an activity tracker worn around your wrist.

Maximal heart rate

This is the hardest your heart could beat when you’re active, not something you could sustain very long. Your maximal heart rate is not influenced by how much exercise you do, or your fitness level.

Most activity trackers don’t measure it accurately anyway, so you might as well forget about this one.

VO₂max

Your muscles need oxygen to work. The more oxygen your body can process, the harder you can work, and therefore the fitter you are.

VO₂max is the volume (V) of oxygen (O₂) we could breathe maximally (max) over a one minute interval, expressed as millilitres of oxygen per kilogram of body weight per minute (ml/kg/min). Inactive women and men would have a VO₂max lower than 30 and 40 ml/kg/min, respectively. A reasonably good VO₂max would be mid thirties and higher for women and mid forties and higher for men.

VO₂max is another measure of fitness that correlates well with all-cause mortality: the higher it is, the lower your risk of dying.

For athletes, VO₂max is usually measured in a lab on a treadmill while wearing a mask that measures oxygen consumption. Activity trackers instead look at your running speed (using a GPS chip) and your heart rate and compare these measures to values from other people.

If you can run fast with a low heart rate your tracker will assume you are relatively fit, resulting in a higher VO₂max. These estimates are not very accurate as they are based on lots of assumptions. However, the error of the measurement is reasonably consistent. This means if your VO₂max is gradually increasing, you are likely to be getting fitter.

So what’s the take-home message? Focus on how many steps you take every day or the number of activity minutes you achieve. Even a basic activity tracker will measure these factors relatively accurately. There is no real need to track other measures and pay more for an activity tracker that records them, unless you are getting really serious about exercise.

Corneel Vandelanotte, Professorial Research Fellow: Physical Activity and Health, CQUniversity Australia

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