Muscle growth doesn’t come quickly to us natural lifters. That’s why you want to cherish every pound of muscle you build. The last thing we want to do is lose a significant amount of muscle during a fat loss phase.
If you approach your fat loss phase incorrectly, this can occur. But as you’ll see in this post, it’s more than possible to preserve muscle well while you are in a fat loss phase.
How Fat Loss Affects Muscle Growth
When your body is in an energy deficit, it will have to tap into its energy reserves. The most obvious reserve to turn to is body fat. This is why your body gains fat when you overfeed it, so it can use it in times of food scarcity.
But body fat isn’t the only energy source available that is used to balance out an energy deficit. For instance, research shows that protein breakdown also increases when you’re in a calorie deficit.
The human body builds (protein synthesis) and breaks down (protein breakdown) muscle proteins every day. If the number of muscle proteins you’ve built exceeds the number of muscle proteins you’ve broken down, you’ve built muscle.
In a calorie deficit, research shows that protein synthesis rates drop and protein breakdown rates increase. This negatively affects the amount of muscle you build and can potentially make you lose muscle if your approach is too aggressive.
There are 3 main factors that can minimize (or maximize if you do it incorrectly) the negative effect an energy deficit has on muscle growth.
We’ll discuss how you can use these factors to your advantage, one by one.
Caloric Intake
You’re probably thinking that I’m going to tell you to ”maintain a small deficit” or ”keep fat loss very slow”. I’m not, the slower you’re losing fat, the longer it takes to reach your fat loss goal. Why is this not beneficial for muscle growth, you ask?
Well, research shows that the longer you’re underfeeding your body, the more susceptible to muscle loss you become. That’s why you don’t want to drag out your fat loss phase if there is no need to.
That said, severe calorie restriction is also not the answer (unless you’re morbidly obese). Research by the Norwegian School of Sport Sciences shows that muscle and strength loss is significant when non-obese individuals eat way below their caloric requirements.
So how many calories should you eat to maximize muscle preservation while still losing fat rapidly?
A good starting point is found in a scientific review paper, which was designed to provide evidence-based recommendations for natural bodybuilders (people like you, who want to gain more muscle and lose more fat).
They found that losing 0.5-1% of total body weight per week is a good starting point for those who want to improve their body composition. This generally can be achieved by maintaining a calorie deficit of roughly 20-25%. Like in this study, in which athletes lost an average of 1.2 lbs per week by maintaining a deficit of 24%.
Protein Intake
The role of protein during a fat loss phase is very simple: it increases muscle preservation and keeps you full for longer. That’s why it’s highly beneficial to maintain a somewhat high protein intake during your fat loss phase.
But most people take this the wrong way. Because a higher protein intake is beneficial, they think they should stuff themselves with protein every 2-3 hours. This is not necessary.
A 2017 systematic review indicates that consuming as low as 0.7g/lb. (1.6g/kg) of body weight is able to maximize muscle growth. If you want to err on the safe side of things and make use of the satiating effects of protein, you can feel free to consume more protein in a day.
Resistance Training
The human body is quite fascinating. It’s able to survive in extreme circumstances due to its adaptive capabilities and efficiency.
It won’t hold on to muscle tissue that is not used for an extended period of time. It sees this as unnecessary extra weight, which costs energy to preserve. For the same reason, you won’t just build muscle.
You need to give your body a reason to preserve and eventually build muscle. You provide this stimulus simply by using your muscles in training. This helps explain why research by the Washington University shows that weight training increases muscle preservation in calorie-restricted individuals.
To maximize muscle preservation and perhaps even build muscle during your fat loss phase (depending on how close you are to you are to your genetic limit), you need to train for progressive overload.
The training you perform in the gym is considered a stress that forces an adaptive response. Your body adapts to training by building bigger and stronger muscles so that it can deal more efficiently with the provided training stress in the near future. So for consistent muscle growth to occur, you need to constantly challenge your muscles beyond their present capacity (a.k.a. Progressive Overload)
Final Words
As you just read in this blog post, you do not need to go to any extremes to preserve muscle during a fat loss phase. As long as you eat at an appropriate deficit, consume enough protein and train regularly, you will not lose muscle.
If you are interested in learning more about maximizing your muscular potential, check out my new eBook “The Art & Science of Muscle Growth. This book translates the currently available scientific data about muscle growth in “Basic English”, so everyone can start implementing an evidence-based approach to training and nutrition.
Quick question: do you think refeeds are necessary or beneficial when dieting?
P.s. Your research-based take on nutrition and exercise is refreshing. So much bs and junk science out there. Keep on doing what you’re doing!
Hey! Thanks for the kind remark 🙂
As you get deeper into your fat loss phase, metabolic damage increases (you start burning less calories). Refeeds help slow down the metabolic adaptations your body is going through and therefore they are beneficial.
You can read more about refeeds and diet breaks in this post: https://www.iwannaburnfat.com/diet-breaks/