A weight-loss programme requires a carefully balanced diet and exercise routine. Photo / Getty Images
Attune your diet and revise your exercise routine to avoid unintentionally losing your hard-earned muscle.
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.
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.
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 (1250 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 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.
What can you 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 on to 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.
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.
Nick Fuller is a research program leader at the Charles Perkins Centre at University of Sydney.
This article is republished from The Conversation under a Creative Commons licence. Read the original article.