How to Prevent Muscle Loss During Weight Loss

Weight loss is often associated with improvements in health, but losing weight isn't always as simple as seeing the number on the scales decrease. When you lose weight, your body can lose both fat and muscle. Understanding how to prevent muscle loss during weight loss is therefore important for maintaining strength, supporting your metabolism and protecting your long-term health.

Although some loss of lean body mass can occur during weight loss, there are practical ways to help preserve muscle. Eating enough protein, incorporating resistance training and avoiding overly restrictive diets can all make a difference.

At Nutrition & Co, our registered dietitians help individuals achieve their nutrition and health goals through personalised, evidence-based advice. In this guide, we'll explore why muscle loss happens during weight loss and what you can do to maintain muscle mass while working towards your goals.

Why Does Muscle Loss Happen During Weight Loss?

When you lose weight, your body typically uses stored energy to compensate for consuming fewer calo

ries than it needs. Although the aim of weight loss is often to reduce body fat, some weight can also be lost from lean body mass, which includes muscle, water and other non-fat tissues.

Muscle loss during weight loss can be influenced by several factors, including:

• Insufficient protein intake: Protein provides the amino acids needed to maintain and repair muscle tissue.

• Lack of resistance training: Without regular muscle-strengthening activity, the body receives less stimulus to maintain muscle.

• Excessive calorie restriction: Very low energy intake can increase the risk of losing lean tissue.

• Ageing: Muscle mass naturally tends to decline with age, making muscle preservation particularly important for older adults.

• Rapid weight loss: Losing weight quickly, particularly without adequate nutrition or exercise, may increase the proportion of weight lost from lean tissue.

Importantly, not all lean mass lost during weight loss represents skeletal muscle. Changes in body water and other tissues can also contribute.

Understanding these factors can help you make more informed decisions about your approach to weight management. For more advice, explore our guide on how to achieve sustainable weight loss.

1. Eat Enough Protein to Maintain Muscle Mass

Protein plays an essential role in maintaining muscle mass, particularly when you're losing weight. Your body uses dietary protein to repair and maintain tissues, including skeletal muscle. During weight loss, adequate protein intake helps support muscle protein synthesis and may reduce muscle loss.

How Much Protein Do You Need During Weight Loss?

The UK Reference Nutrient Intake for protein is approximately 0.75g per kilogram of body weight per day for adults. However, this represents a general population recommendation rather than an optimal target for preserving muscle during weight loss.

Research suggests that higher protein intakes may be beneficial for maintaining muscle mass during an energy deficit, particularly when combined with resistance training.

For many otherwise healthy adults undergoing weight loss, approximately 1.2–1.6g of protein per kilogram of body weight per day may be a useful starting range, although individual requirements vary.

However, protein requirements depend on factors such as age, activity levels, body composition and medical history. For individuals living with obesity, calculations based on current body weight may overestimate requirements, so a dietitian may use an adjusted or reference weight. People with kidney disease or other medical conditions should seek individual advice before substantially increasing protein intake.

Include Protein-Rich Foods Throughout the Day

Rather than consuming most of your protein at one meal, try incorporating protein-rich foods regularly throughout the day.

Examples include:

Food	Approximate protein content
Chicken breast, cooked (100g)	30g
Salmon, cooked (100g)	22–25g
Greek yoghurt (170g)	10–17g, depending on brand
Eggs (2 medium)	13g
Firm tofu (100g)	12–17g
Lentils, cooked (150g)	11–13g
Cottage cheese (100g)	11–13g

These values are approximate and vary depending on the product and preparation method. Combining different protein sources can also help provide a varied range of nutrients.

For more information, read our guide to understanding protein, carbohydrates and fats.

Dietitian tip: Aim to include a source of protein at each main meal. For example, try Greek yoghurt at breakfast, a chicken or tofu wrap at lunch and salmon with potatoes and vegetables for dinner.

2. Include Resistance Training in Your Routine

One of the most effective ways to prevent muscle loss during weight loss is to combine adequate protein intake with resistance training. Resistance training involves working your muscles against a force, such as weights, resistance bands or your own body weight.

This stimulates the muscles and helps maintain strength and muscle tissue, even when energy intake is reduced.

How Often Should You Strength Train?

The UK Chief Medical Officers' physical activity guidelines recommend that adults incorporate muscle-strengthening activities on at least two days per week.

Activities could include:

• Weightlifting or resistance machines

• Bodyweight exercises, such as squats and press-ups

• Resistance band exercises

• Pilates and other appropriately challenging strengthening activities

• Functional movements, such as lifting and carrying

You don't necessarily need a gym membership to benefit from resistance training.

For beginners, two full-body sessions per week can be a manageable starting point. Gradually increasing the challenge as your strength improves can help maintain progress.

The NHS guide to improving strength and flexibility provides practical examples of strengthening exercises.

Is Cardio Enough to Prevent Muscle Loss?

Cardiovascular exercise, such as walking, running, cycling and swimming, provides important benefits for heart health, fitness and overall wellbeing.

However, cardio alone may not provide enough stimulus to maintain muscle mass during weight loss. A combination of aerobic activity and resistance training is generally more beneficial for supporting both cardiovascular fitness and muscle strength.

If you're regularly exercising, our sports nutrition resources explore how to fuel your training and recovery effectively.

3. Avoid Overly Restrictive Diets

Although creating an energy deficit is generally necessary for weight loss, reducing calorie intake too aggressively can make it more difficult to preserve muscle.

Very restrictive diets may result in:

• Inadequate protein and overall nutrient intake

• Reduced energy for physical activity

• Poorer exercise performance and recovery

• Increased fatigue

• Greater difficulty maintaining dietary changes long term

A more gradual, sustainable approach can help support adequate nutrition while allowing you to remain physically active.

What Is a Healthy Rate of Weight Loss?

The appropriate rate of weight loss varies depending on individual circumstances.

For some adults, a gradual reduction of approximately 0.5–1kg per week may be appropriate, but this is not a universal target. People with lower starting weights may benefit from a slower approach, while those receiving specialist obesity treatment may follow different recommendations. The most important consideration is whether your approach supports your health, nutritional requirements and long-term wellbeing.

Weight loss is also not appropriate or necessary for everyone.

Rather than focusing exclusively on the scales, consider other indicators of progress, such as improvements in strength, fitness, energy levels and daily functioning.

Our article on what to eat for sustainable weight loss provides practical meal inspiration without relying on restrictive dieting.

4. Don't Forget Carbohydrates and Healthy Fats

When trying to lose weight, it's common to focus heavily on calories and protein.

However, carbohydrates and dietary fats also play important roles in supporting muscle preservation, exercise performance and overall health.

Why Carbohydrates Matter

Carbohydrates provide an important source of energy, particularly during moderate- to high-intensity exercise. Consuming adequate carbohydrates can help you maintain training intensity and support recovery.

Good sources include:

• Wholegrain bread, pasta and rice

• Potatoes and sweet potatoes

• Oats and other wholegrain cereals

• Fruit

• Beans and pulses

You don't need to eliminate carbohydrates to lose weight. Instead, focus on including appropriate portions alongside protein, vegetables and sources of healthy fats.

Include Sources of Unsaturated Fat

Dietary fats are essential for several bodily functions, including the absorption of fat-soluble vitamins and the maintenance of cell membranes.

Sources of unsaturated fats include olive oil, nuts, seeds and oily fish.

Including these foods as part of a balanced diet helps support overall nutritional adequacy. For more inspiration, explore our healthy eating articles.

5. Prioritise Sleep and Recovery

Nutrition and exercise are essential for maintaining muscle, but recovery also matters.

Sleep supports normal physiological processes involved in tissue repair, hormonal regulation and recovery from exercise.

Consistently inadequate sleep may negatively affect exercise performance and influence body composition during weight loss. Most adults should aim for approximately 7-9 hours of sleep per night, although individual requirements vary.

To support better recovery:

• Maintain a consistent sleep schedule where possible.

• Allow sufficient recovery time between demanding training sessions.

• Avoid increasing exercise intensity too quickly.

• Eat enough to support your daily activities and training.

• Include rest days when needed.

  
  

Remember that exercise creates the stimulus for muscle adaptation, while adequate nutrition and recovery help support the process.

6. Do You Need Protein Supplements to Prevent Muscle Loss?

Protein powders and shakes can be convenient, but they aren't essential for maintaining muscle during weight loss. Most people can meet their protein requirements through a varied diet containing foods such as dairy products, eggs, fish, meat, tofu and pulses.

However, supplements may be useful when:

• Appetite is reduced.

• Meeting protein requirements through food is difficult.

• You have a particularly busy schedule.

• Your training demands increase your protein requirements.

For example, a protein shake may be a practical option after exercise if a meal isn't available.

However, supplements shouldn't routinely replace balanced meals, as whole foods provide additional nutrients, including fibre, vitamins and minerals. It's also important to remember that consuming more protein than your body requires doesn't automatically result in greater muscle retention. The combination of appropriate protein intake, resistance training and adequate overall nutrition is more important than any individual supplement.

7. When Should You Speak to a Dietitian?

Preventing muscle loss during weight loss isn't always straightforward, particularly when nutritional requirements are affected by medical conditions, medications or changes in appetite. A registered dietitian can provide personalised advice based on your health, lifestyle and goals.

Dietetic support may be particularly beneficial if you:

• Are taking weight-loss medications.

• Have experienced rapid or unintentional weight loss.

• Are struggling to consume enough protein.

• Have noticed changes in strength or physical function.

• Are an older adult concerned about muscle loss.

• Have a medical condition affecting your nutritional requirements.

At Nutrition & Co, our registered dietitians provide individualised nutrition advice to help you develop sustainable habits that support your health and wellbeing.

Frequently Asked Questions (FAQs)

1. Can you lose weight without losing muscle?

It is possible to minimise muscle loss during weight loss, although completely preventing changes in lean body mass isn't always realistic.

The most effective approach generally involves combining adequate protein intake with regular resistance training and avoiding unnecessarily restrictive diets. Individual factors, including age, starting body composition and the amount of weight lost, can influence how much muscle is retained.

2. How much protein should I eat to prevent muscle loss during weight loss?

For many healthy adults, approximately 1.2–1.6g of protein per kilogram of body weight daily may help support muscle preservation during weight loss, particularly alongside resistance training. However, this isn't an appropriate target for everyone. Protein requirements vary depending on age, body composition, activity levels and medical conditions. Individuals living with obesity may require an alternative method of calculating protein needs. A registered dietitian can help determine an appropriate intake.

3. Does walking help prevent muscle loss during weight loss?

Walking is an excellent form of physical activity that supports cardiovascular health, mobility and overall wellbeing. However, walking alone may not provide sufficient resistance to maintain muscle mass during weight loss, particularly in people who are already physically active. Combining walking with muscle-strengthening activities, such as resistance bands, weights or bodyweight exercises, is generally more effective for supporting muscle strength. The NHS physical activity guidelines recommend incorporating muscle-strengthening activities on at least two days each week.

Looking for personalised support?

The team at Nutrition & Co can help you develop an evidence-based nutrition plan tailored to your individual needs, whether you're managing your weight, improving your strength or navigating weight-loss medication.