lose fat and maintain muscle mass, photo of sculpted physique.
lose fat and maintain muscle mass

If you’re looking to lose fat and maintain muscle mass, this article will provide you with the resources you need to start that process. This is part 2 of a 3-part series. I’d recommend getting a full understanding of part 1 first with Lose Fat and Reduce Body Fat Percentage with Basic Math. Then after reading this post (part 2), follow along to part 3 with How to Calculate Macros to Lose Fat and Maintain Muscle Mass to further dial in your fat loss and muscle maintenance efforts.

If you want to lose fat more effectively, this follow-up post is an important read to help you understand how you can reduce body fat and prevent losing lean muscle mass in the process. We will touch on four critical components of fat-loss and muscle maintenance to get you closer to the body of your dreams. The goal is to accomplish fat-loss without damaging your metabolism and sacrificing muscle.

If you’re not interested in maintaining muscle mass and the skinny-fat look is what you’re going for, then this article is probably not in your best interest to read.

How to Lose Fat and Maintain Muscle Mass

1. Eat at a Moderate Caloric Deficit Based on Your Total Daily Energy Expenditure (TDEE) To Lose Fat.

Eating at a caloric deficit is the tried and true method for losing body fat. However, it is important to understand that caloric restriction should be done in moderation if you want to prevent losing muscle mass in the process. If you have medical, hormonal, or gut issues, you should seek guidance from a physician before embarking on a fat-loss journey. When you reduce calories and increase physical exercise too severely, there is a good chance you will lose muscle as well. This is supported by numerous scientific studies and reviews, such as this one: Changes in Fat-Free Mass During Significant Weight Loss: A Systemic Review.

This article reviews 16 medical and 17 surgical weight-loss studies. The analysis of these studies indicates that very-low-calorie diets provide rapid weight-loss, but also contribute to a substantial loss in fat-free mass (basically everything in your body that isn’t fat). Loss of muscle mass was positively correlated with increased levels of caloric restriction and exercise.

Why should you care about keeping muscle? Well, an increase in muscle mass has been shown to increase your resting metabolic rate (RMR). This basically means you need to eat more to maintain the hard-earned muscles you’ve spent countless hours building. Maintaining and building muscle are what gives you that “toned” look that many people seek to attain. You can’t actually “tone” muscles, which is why the term is quoted here, but I’ve included it as it’s widely used by a portion of the general population who want a more sculpted physique. Muscles either get bigger or smaller. The shape is ultimately dictated by your genetics.

meal prep for fat loss and muscle maintenance
meal prepping is key for fat loss and muscle maintenance

The recommended calorie-intake required to promote fat-loss while maintaining muscle mass is a 20-25% reduction in calories per day based on how your TDEE is calculated. To figure out what your TDEE is, you can refer to my previous post (part 1 of 3) to calculate how many calories you need for maintenance and how many calories to consume to lose weight. I’d recommend starting at a 20% deficit and monitoring changes in body composition and strength. If you’re not overweight or obese, you should be targeting about 1-2 pounds per week, depending on your weight. If you’re already lean, then 0.5-1 pound is more realistic. Any more than that, you’ll increase the likelihood of muscle loss. Feel free to scale to 25%, but if you do, you need to ensure you can at least maintain your strength. Loss of strength typically translates to a decrease in muscle mass.

This recommendation is supported by many studies analyzing changes in muscle mass during calorie-restricted diets. This is one example: Effect of Two Different Weight-Loss Rates on Body Composition and Strength and Power-Related Performance in Elite Athletes.

In this article, a weekly loss of 0.5 vs. 1kg (1.1 vs. 2.2lbs) per week in athletes eating roughly 2,500 calories per day demonstrated that a slower weight-loss program had more positive effects on lean body mass and performance than the faster weight-loss intervention. Slower rate (SR) weight-loss was defined as an energy intake that was reduced by roughly 19%, whereas fast rate (FR) weight-loss was set at around 30% of calories per day. What’s interesting is that the SR group was observed to have significantly improved lean body mass and performance, while the FR group demonstrated no significant increase in either.

So the first and most important concept in losing body fat while maintaining muscle mass then, is to eat at a caloric deficit of roughly 20-25% of your total daily energy expenditure, scaled according to changes in current body composition and physical activity levels.

2. Eat Enough Protein to Preserve Muscle Mass While Losing Fat.

Another critical component to losing fat and not muscle is to follow a high-protein diet. Protein is the most important macronutrient in a weight-loss diet. You need to be keenly aware of moderating your protein-intake when you’re trying to maintain lean muscle mass on a fat-loss journey. There have been multiple studies proving that an elevated protein-intake well above the RDA is necessary to keep as much of your lean body weight as possible.

In some special cases, you can actually build muscle while losing fat. We’ll save that for another post. If you’ve been weight training properly for over a year, the more realistic goal is to maintain muscle mass rather than to increase it during a cutting phase. The latter becomes close to impossible when you’ve got years of proper training under your belt. This is when bulking and cutting or high/low calorie cycling increases in importance, but that is beyond this posts discussion.

lots of protein
protein galore!

Below are two different studies that illustrate the benefits of high-protein consumption while on calorie-restricted diets. The first study recommends 2.3-3.1 g/kg (1.04-1.41g/lb) of fat-free mass.

The second study recommends 1.8-2.7g/kg (0.82-1.22g/lb) of total body weight to optimize the ratio of fat-to-lean tissue mass during hypoenergetic periods (calorie-restrictive periods). Protein-intake should be scaled toward the higher ends when severity of caloric-restriction and intensity of exercise is increased. Alternatively, an increase in fat-intake can work as well. Whether you should go higher in protein or fat will depend on how your body best adapts to specific elevated levels of substrates (carbs, fats, proteins).

  • Dietary Protein For Athletes: From Requirements To Optimum Adaptation
    • This article provides another perspective on protein requirements for individuals who seek to prevent lean muscle mass loss during caloric restriction when promoting fat-loss. The recommendation here is that elevated protein consumption, as high as 1.8-2.0g/kg per day (0.82-0.91g/lb) may be advantageous for those looking to lose fat and maintain muscle mass.

As individuals respond to nutrients and physical stressors differently, I recommend playing around with protein and fat intake and sticking with the amount that works best for your body. Although the second study recommends a smaller range than the first, I, personally, hover around 1g of protein per pound of lean body weight. Protein intakes at the lower ranges of the scale may be sufficient for those who don’t engage in as much physical activity or who have less muscle tissue to preserve.

One gram per pound of lean mass is widely accepted as the minimum requirement in the bodybuilding world. That requirement can get as high as 1.5g/lb or higher for competitive bodybuilders on severely calorie and carbohydrate-restricted diets, but that’s when ammonia toxicity may be a concern. I was eating about 1.5g/lb of body weight for a short period during bikini contest prep. For the normal person who isn’t a competitive bodybuilder, eating at such high levels of protein is unnecessary and hasn’t proved to be exceptionally beneficial.

The second key component to lose body fat and not muscle is to eat a high-protein diet at a minimum of 1g of protein per pound of  lean body mass. This can be scaled upward depending on degree of caloric-restriction and exercise intensity.

3. Lift Heavy Weight To Maintain Muscle When Losing Fat.

You can certainly lose body fat and maintain muscle just by eating at a moderate, negative energy balance and keeping protein-intake high. When you add resistance training to that combo, there’s a good chance you’ll maintain more muscle mass than if you didn’t do any type of strength training.

This is demonstrated in the following study: Resistance Weight Training During Caloric Restriction Enhances Lean Body Weight Maintenance. This study assesses the impact of weight training on weight-loss and maintenance of lean body mass in calorie-restricted diets. There were four test groups:

  1. Control (C)
  2. Diet Without Exercise (DO)
  3. Diet Plus Weight Training (DPE)
  4. Weight Training Without Diet (EO)

It was found that weight training resulted in comparable muscle area and strength gains for the DPE and EO test groups. Conversely, the control group and DO groups saw reductions in muscle mass.

barbell curl - resistance weight training
barbell curl – resistance weight training

Another study, Effects of Resistance vs. Aerobic Training Combined With An 800 Calorie Liquid Diet on Lean Body Mass and Resting Metabolic Rate illustrates similar findings. This study focuses on a comparison between resistance and aerobic training during a calorie-restricted diet. The test was conducted on two groups that were assigned to very-low-calorie diets.

One group engaged in aerobic exercise for one hour, four times per week (C+D). The second group performed resistance training three days per week at 10 stations (R+D). The results were that the C+D group lost a significant amount of lean muscle mass, while there was no decrease in the R+D group. This shows that intensive, high-volume resistance training programs can result in the preservation of lean muscle mass.

The third key component in maintaining muscle while reducing body fat is to do resistance training. You should aim to either maintain or increase your strength, though the latter may be quite difficult when eating in a caloric deficit.

4. When Losing Fat, Cardio is Optional.

Yes, I said it. When losing fat, cardio is not absolutely necessary. This last piece of the puzzle is not a critical component of fat-loss, but it is worth a brief discussion for its potential impact on fat and muscle loss. It is also often used excessively by dieters, which can actually harm you more than it can help and can encourage the skinny-fat look.

the skinny-fat look
the skinny-fat look

Adding cardio into your workouts can definitely speed up the fat-loss process. However, many people tend to fixate on the idea that more cardio is always better. Yes, you will expend more energy or calories, but if you are pounding away on the treadmill for hours and hours per week, you may actually create a larger than desired caloric deficit. As cited earlier, rapid fat-loss can contribute to a substantial loss in muscle tissue. The last thing you want to do is unintentionally reduce your metabolic rate and wreck your metabolism. Stayed tuned for a future post that will teach you how to reverse metabolic damage.

Another downside to excessive steady-state cardio while on a calorie-restricted diet is that you run the risk of overtraining, which is not a good state to be in. It can negatively alter your mood, induce fatigue and lack of motivation, and impact your performance. When you are in a caloric-deficit, your body is already undergoing a tremendous amount of stress. When you tack on hour-long cardio sessions multiple times per week, you’re just piling on more stress that your body doesn’t have the energy to recover from. Overtraining kicks in when there’s an imbalance between stress and stress tolerance, exercise and exercise capacity, and training and recovery.

My steady-state cardio sessions in the gym hardly ever exceed 30-40 minutes. I cut them even shorter to 20-25 minutes when I’m doing high intensity interval training (HIIT) because it’s more taxing on the body. HIIT is proven to be more effective than steady-state cardio for fat-loss and preserving muscle mass. If you want to know why HIIT is so good for you, here are 4 Reasons Why You Should Be Doing HIIT.

hiit training with a track and field day showing legs, protein bottle on track.
hiit training on a track and field day

When I’m eating at a caloric-deficit, I don’t usually do cardio more than three times per week because I don’t want a lack of recovery to impact the intensity of my strength-training sessions. I will sometimes push that to 4-5 times per week depending on energy levels, but those additional sessions are performed at relatively low intensities (such as walking at an incline and hiking at a slow and steady pace). Some would argue that it’s best to do less or none at all, but I actually enjoy cardio and want to stay conditioned year-round. Plus, it makes me feel great and improves my cardiovascular health. Thus, cardio is always in my workout regimen, no matter what my goals are. Frequency and intensity, however, are modified based on goals and what my body tells me.

The last key component in preserving muscle mass during fat-loss then, is to avoid excessive amounts of cardio. Use cardio sparingly and watch out for symptoms of overtraining.

So there you have it. These are four fundamental concepts that one should understand if your goal is to lose fat and maintain muscle mass.

Ting Wang