How to Lose Fat Without Losing Muscle (Evidence-Based) - Perfect Keto

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How to Lose Fat Without Losing Muscle (Evidence-Based)


Reducing your body weight while maintaining muscle mass (or even gaining more) is a challenging goal, but definitely not impossible.

To achieve this, you need a combination of strategies, including the right nutrition and an exercise plan. Furthermore, you’ll need to support your body through rest, hydration, and replacing lost electrolytes.

This guide explains the mechanism behind fat loss and muscle loss, and tips on how to burn fat without losing muscle.

How Fat Loss Happens

Your body fat percentage decreases when you cut calories and enter a calorie deficit, whether you do it intentionally or not. You probably know what a calorie deficit is, which means consuming fewer calories (from foods and drinks) than your body burns. For instance, if you burn 1,500 calories a day but you only eat 800 calories, then you’re in a 700 calorie deficit (*).

However, it’s important to note that calories aren’t all the same. Meaning, it’s not just the amount of calories you consume that matters, but also where those calories come from.

Between a highly processed food and natural food with the same calorie count, you’re more likely to get a better fat burn from choosing the latter. This is because processed foods contain added sugars, artificial flavors, and vegetable oils that cause inflammation and cravings (which promote overeating) (*).

Also, when it comes to cutting without losing muscle, it’s helpful to keep in mind that losing fat becomes more difficult as you get older. Lean muscle naturally declines about 3-8% after the age of 30 and the rate increases even more after 60 (*).And not to mention, hormonal changes in women during menopause (*).

While these physical changes are inevitable, they can be reversed or fixed by consistently following a healthy dietary pattern, physical activity (weightlifting and cardio), and losing weight at a steady pace.

How Muscle Loss Happens

Muscle loss, also known as muscle atrophy, is when your muscle mass thins or wastes away. It can happen for many reasons and two common factors are a lack of physical activity and poor nutrition (or a diet that’s lacking in foods that promote muscle synthesis) (*).

Advanced age also leads to sarcopenia or age-related muscle loss, as mentioned in the previous section of this article.

During muscle atrophy, the size of your cell decreases due to the loss of protein and organelles (or structures) inside the cell. The process of protein breakdown increases as well as proteasomal ATP-dependent activity (*).

It’s no secret that protein is considered a “king of muscle” since it provides your body with amino acids. Out of the nine essential amino acids, three are responsible for muscle maintenance — leucine, isoleucine, valine (*). Furthermore, your protein needs increase if you are older.

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Important: Certain conditions and medications cause muscles to waste away, so make sure to speak with your doctor if you are concerned.

Can You Lose Fat Without Losing Muscle?

Yes, you can. While it may seem like weight loss is associated with muscle loss, this doesn’t have to be the case. To lose fat without losing muscle in the process of weight loss or body recomposition, make sure that you don’t cut calories too drastically. In other words, your fat loss efforts should be gradual — there should be a balance between pushing yourself and easing up.

Being in a calorie deficit is one of the basic rules for weight loss, but don’t do go overboard and for a longer time to avoid slowing your metabolism (*). A good rule of thumb is to aim for a deficit of 500 calories daily (depending on your maintenance calories) from your regular diet to lose 1 pound per week (*).

You can create a calorie deficit naturally while preserving lean body mass by prioritizing whole foods (such as in a clean keto diet), increasing your physical activity, upping your protein intake — or all of the above.

Maintaining muscle mass isn’t just for gym-goers and fitness enthusiasts, but it’s especially vital for your overall health.

One review noted that increasing muscle through exercise training creates mechanical stress in the skeleton. In other words, strengthening your muscles builds stronger bones (*). Another reason to preserve or gain muscle mass is to improve brain health and cognition (*).

7 Ways to Burn Fat Without Burning Muscle

If you want to learn how to lose weight without losing muscle mass, use these strategies. More importantly, remember that everyone’s weight loss experience is different. So, while following the recommendations below, stay patient and don’t do anything drastic that will harm your health.

1. Optimize your protein intake.

Increasing the amount of protein in your diet is one of the keys to losing fat and protecting your muscle tissue. Protein promotes fat loss naturally due to its higher thermic effect of food (TEF) — about 20-30% — than carbohydrates and fat (*).

It means that when you eat a protein-rich meal, 20-30% of the calories from that meal are burned during digestion.

Protein is the most satiating macronutrient, which suppresses your appetite and reduces hunger (*). Plus, it spares lean muscle during periods of calorie restriction.

According to the National Academy of Sports Medicine, people who want to lose weight should aim to consume 0.73 to 1 gram per pound (*). Healthy protein sources include whole foods like red meat, chicken, eggs, fish and seafood, and nuts.

2. Do cardio exercises.

Cardiovascular workouts burn calories and body fat.

When it comes to the best exercise to use for fat loss, you might think that you need to do high-impact activities such as burpees, sprinting, and other jumping movements. The advantage of HIIT (high-intensity interval training) is that it pushes you beyond your comfort zone, thereby enhancing your performance and calorie afterburn.

Steady-state cardio such as riding the exercise bike, treadmill, swimming, or brisk walking is also as important. It provides the opportunity to exercise in a more relaxed way, can be a good option for active rest days, and builds endurance (* , *).

3. Incorporate strength training.

Strength training is a vital part of increasing your overall fitness, not to mention its other benefits beyond the gym — such as bone health (slowing bone loss) and improvements in mood. When combined with cardio exercise, strength training may boost good cholesterol levels (* , *, *).

Examples of strength training include lifting free weights (dumbbells or barbells), resistance band workouts, and using your own body weight (like squats, pushups, and lunges).

As an additional tip, don’t be afraid to lift heavy weights. Building muscle can improve your body composition. Plus, increasing muscle mass also increases your resting metabolism, helping you lose more weight and keep it off (*).

4. Eat carbohydrates around your workouts.

Excessive consumption of carbohydrates, especially refined carbs, contributes to excess stored energy, causing weight gain (*).

However, you don’t have to completely avoid carbs or live a carb-free life. Instead, you can use carbs strategically in a way that allows you to push harder at the gym. People looking to build strength and muscle do this, and those following a targeted keto diet for performance gains.

Choose light and easy-to-digest carb foods such as white bread or bananas. Eat them 30 minutes prior to your exercise session.

5. Avoid restrictive dieting.

Self-discipline plays a crucial role in helping you stick to your short-term and long-term goals. Just be careful to not go too extreme.

Feelings of deprivation may trigger overeating, especially when tempting foods are present. A randomized controlled trial showed that chocolate-deprived restrained eaters ate more chocolate and that they had more food cravings than did unrestrained eaters (*).

6. Make time for rest and recovery.

Rest days are days when you take a break from your regular exercise routine. It’s important to take at least one rest day a week depending on the intensity of your regimen.

A rest day has plenty of benefits, such as relieving and repairing sore muscles, allowing your mind to rest (a mental break from your fitness), and preventing injuries.

Speaking of rest and recovery, you may have heard of a “diet break,” which is a popular strategy used in the fitness community to counteract adaptive thermogenesis — a phenomenon in which metabolic rate decreases as a result of prolonged calorie restriction or undereating.

In a randomized controlled trial, participants were divided into two groups: one group stayed on the diet for 16 weeks while the other group stayed on the diet for 2 weeks, then took a 2-week break. The results of the study revealed that those who took a break ended up losing more weight and gained less weight after the study was done (*).

7. Don’t forget proper hydration and replenishing electrolytes.

A lack of hydration reduces your strength and high-intensity endurance. This might be because of the fact that proper hydration enhances blood flow to your muscles, allowing for optimal performance (*).

If the body is dehydrated, electrolyte imbalances might occur, which could lead to symptoms like muscle cramps during or immediately after exercise (*).

Make sure to drink fluids before and after a workout. You may also take a sports drink with sodium and potassium. Perfect Keto’s Daily Electrolytes contains these electrolytes and are free of added sugars and calories to support your physical activity and fat loss goals.

Important advice: Don’t hesitate to seek help from a certified trainer who can put together a diet and fitness plan that’s personalized, safe, and effective. Having a trainer can also go a long way in keeping you accountable.


Frequently Asked Questions

Discover more answers to the most common questions on how to maintain muscle while cutting:

How do I know if my body is in fat-burning mode?

The most definitive way to tell is by checking your ketone levels. Ketones are produced when your body starts tapping into its stored fat to sustain your energy. You can test for ketone levels using a ketone urine testing strip or a blood ketone meter.

Meanwhile, you can also watch out for symptoms of increased fat-burning, such as reduced hunger in between meals, more stable energy levels throughout the day, and the ability to exercise even in a fasted state.

Does my body burn fat or muscle first?

Your body burns through its fat stores first, and this happens after depleting its glycogen reserves (the storage form of carbohydrates). However, you could lose muscle at the same time if you cut too many calories and don’t eat enough protein, a macronutrient that’s so important for maintaining lean muscle.

How can I tell if I’m losing muscle and gaining fat?

Weigh yourself on the scale and measure your body fat using a skinfold caliper or a body composition scan (DEXA). If you see increasing numbers, then you’re likely gaining fat. Neglecting your dietary protein intake and physical activity are also indicators that you’re losing muscle.

Does sweating burn fat?

No, sweating does not burn fat. Sweating is your body’s own mechanism of regulating its temperature, especially if you’re exercising in warm environments. You don’t just lose water when you sweat, but also electrolytes like sodium, chloride, and potassium.

Should I build muscle or lose fat first?

If you have a lot of body fat to lose, then it’s best to focus on losing that fat first. When doing this, don’t just focus on cardio exercises, but also incorporate resistance training (or strength training) to increase your metabolism and make the process of fat-burning easier.

The Bottom Line

Losing fat without losing muscle mass in the process entails a holistic approach.

It’s not just about eating less and moving more, but rather multiple strategies which include optimizing your protein intake, strength training and cardio workouts, eating carbs strategically, not going overboard with dieting, rest, and hydration plus electrolyte intake.

Even if weight loss is your only goal, preserving muscle helps you to build stronger bones and improve your mental health. It may even be beneficial for keeping the weight off by increasing your metabolic rate.

While following all these strategies, be sure to monitor your results. You can do this by checking your body fat percentage as you progress, taking before and after pictures, and noticing how you feel.

25 References

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National Institutes of Health (NIH). Eating highly processed foods linked to weight gain. 2019 May 21

Volpi E et al. Muscle tissue changes with aging. 2010 January 12

Chopra S et al. Weight Management Module for Perimenopausal Women: A Practical Guide for Gynecologists. 2019 October to December

Sartori R et al. Mechanisms of muscle atrophy and hypertrophy: implications in health and disease. 2021 January 12

Bonaldo P et al. Cellular and molecular mechanisms of muscle atrophy. 2013 January

Cleveland Clinic. Amino Acids.

Rosenbaum M et al. Adaptive thermogenesis in humans. 2010 October

Mayo Clinic. Counting calories: Get back to weight-loss basics.

Hong A et al. Effects of Resistance Exercise on Bone Health. 2018 November 30

Sui S et al. Skeletal Muscle Health and Cognitive Function: A Narrative Review. 2020 December 29

Westerterp K. Diet induced thermogenesis. 2004 August 18

Morell P et al. Revisiting the role of protein-induced satiation and satiety. 2017 July


Foster C et al. The Effects of High Intensity Interval Training vs Steady State Training on Aerobic and Anaerobic Capacity. 2015 November 24

Anderson A. The Workout Debate: Experts Weigh in on Cardio VS. HIIT. 2018 March 21

Harvard Health Publishing. Strength training builds more than muscles. 2021 October 13

Westcott W. Resistance Training is Medicine. 2012 July/August

Johns Hopkins Medicine. 3 Kinds of Exercise That Boost Heart Health.

McPherron A et al. Increasing muscle mass to improve metabolism. 2013 April 1

Dam R.M et al. Carbohydrate intake and obesity. 2007 December

Polivy J et al. The effect of deprivation on food cravings and eating behavior in restrained and unrestrained eaters. 2005 December

University of Tasmania. Taking a break from dieting may improve weight loss. 2017 September 18

Judelson D et al. Hydration and muscular performance: does fluid balance affect strength, power and high-intensity endurance?. 2007

Schwellnus M et al. Serum electrolyte concentrations and hydration status are not associated with exercise associated muscle cramping (EAMC) in distance runners.

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