Clean Bulk vs. Dirty Bulk

So you are looking to bulk, but you are not sure if you should do a clean bulk or a dirty bulk. In this article, we’ll decode “clean bulking” and “dirty bulking.”

We will be looking at the differences between clean bulking and dirty bulking. We’ll discuss their pros and cons and what to consider when selecting the one best for your fitness goals. 

What is Bulking?

Having been a dietitian in the fitness world for 15 years, I can confidently say you will undergo many stages while transforming your body. Among these different stages is bulking–a period of time where you focus on eating above your maintenance calories to try build muscle and gain weight.

During a bulk, there are several components to building muscle. These include eating more calories, exercising with intensity in the gym, taking time for recovery and getting quality sleep each night, and including evidence-based supplements in your diet.

Lifting weights, eating in a calorie surplus and getting the right amount of sleep, creates an ideal environment for building muscle mass. For today’s discussion, we will delve into eating more calories, which opens Pandora’s box. We will also talk about supplements needed to optimize muscle-building results when clean or dirty bulking.

How Many More Calories During a Bulk?

The number of calories you need to eat during a bulk will depend on your basal metabolic rate (BRM), your daily activity level, and adding about 10-20% on top of your maintenance calories. (BMR + Activity=Maintenance)

To identify your maintenance level of calories you can use the NIH BODY WEIGHT PLANNER. Now you are going to want to identify your bulking calories which are your maintenance calories plus a 10% or 20% increase.

Use the table below, choose your maintenance calorie levels with an additional 10% or 20% increase.

Maintenance10% increase 20% increase

With the idea of the number of calories for a bulk ironed out, we can now move on to the differences between a dirty bulk vs. a clean bulk. Which comes down to the foods we choose to fulfill said calories. Check out more at macros for a lean bulk.

Dirty Bulking vs. Clean Bulking – what’s the difference?

Dirty bulking vs clean bulking

The difference between a dirty and clean bulk is food choice. Seeing that we (the fitness industry and diet culture) have labeled foods as clean or dirty, good or bad, you can see where we are going with this.

“Dirty” food choices go to those with higher refined sugar, saturated fat, and sodium content. At the same time, having less fiber, vitamins, and minerals. In addition, a dirty bulk typically has no rhyme or reason other than consuming as many calories as possible.

“Clean” food choices are typically going to be the exact opposite. Being lower in refined sugar, saturated fat, and sodium content. At the same time, being higher in fiber, vitamins, and minerals.

In addition to choosing “clean” foods, a clean bulk typically is calculated and precise to hit that 10-20% calorie surplus but not going overboard.

Benefits of clean bulking and dirty bulking

As with anything in nutrition and fitness, there is no 100% right way to do anything. Whether you choose the clean or dirty route, both have their benefits. I have experienced both, and they both have their upsides.

Benefits of a clean bulk

  • When you decide to choose the clean bulking route, there are several benefits you gain.
  • You will get adequate vitamins, minerals, and fiber in your diet.
  • You will more likely optimize the muscle-building process with nutrient-dense foods.
  • You will avoid the consequences of consuming a diet higher in refined sugar, saturated fat, and sodium.
  • I felt less sluggish and had better digestion.
  • You will more likely maintain lean body weight (muscle mass) once bulking is completed.
  • I had fewer cravings for “junk food” high in refined sugar, saturated fat, and sodium.

Benefits of a dirty bulk

When you choose the dirty bulking route, there are several benefits.

  • The food is typically more palatable, allowing you to eat more calories.
  • You don’t have to be as diligent when planning and preparing meals.
  • The volume of food is typically smaller, so you can hit the calorie target easier.
  • I noticed that my training was better, with heavier weights, more reps, etc.

Downsides of clean bulking vs. dirty bulking

Both clean and dirty bulking will have potential upsides, but both have their downsides.

Downsides of clean bulking

  • Eating clean can seem more expensive. Especially when you are buying all your groceries.
  • You have to plan and prepare meals with nutrient-dense consistency.
  • The food can be bland, making it harder to get enough calories.
  • Eating the volume of food you need can be difficult.

Downsides of dirty bulking

  • Dirty bulking tends to be higher in refined sugar, saturated fat, and sodium.
  • Foods for a dirty bulk are typically less nutrient dense than clean foods.
  • It can contribute to weight gain that is not solely muscle mass.
  • There’s an increased risk of health issues related to poor nutrition from a high intake of unhealthy food sources.
  • Eating large amounts of junk food can increase cravings and overeating, leading to extra calories stored as body fat.

How to incorporate both – A flexible approach.

Instead of using a black-or-white approach to either clean or dirty bulking, why not incorporate both? I like to use the 80/20 principle here, with 80% of my bulking diet coming from high-nutrient-value foods and 20% from more processed, maybe less nutrient-value foods.

By following this style, you can achieve your nutritional goals while still having some flexibility to indulge in a smaller meal or even one that does not require planning and preparation. You will get the best of both worlds by getting enough dietary fiber and essential nutrients without sacrificing flavor and convenience!

This method is easier to follow, leading to more consistency and better results, in my opinion. 


As a dietitian, I caution most when it comes to supplements. With that said, there are a few evidence-based supplements that I do recommend, especially to those who are trying to bulk. These include whey protein, creatine monohydrate, and caffeine.

Final thoughts

Whether clean bulking or dirty bulking, the goal should be to optimize muscle growth and minimize fat gain. To achieve this goal, I suggest using a combination of clean and dirty bulking as the preferred approach.

A clean diet of nutrient-dense foods will provide all the essential nutrients and dietary fiber for muscle growth and health. However, clean bulking can be difficult to maintain due to its stricter nature.

That’s why I recommend a flexible approach that combines clean and dirty bulking. This approach allows flexibility while providing enough essential nutrients for optimal results.

Lastly, evidence-based supplements, such as whey protein, creatine monohydrate, and caffeine, can help optimize your results.

I wish you the best of luck on your next bulk!


Remember: this post is for informational purposes only and may not be the best fit for you and your personal situation. It shall not be construed as medical advice. The information and education provided here is not intended or implied to supplement or replace professional medical treatment, advice, and/or diagnosis. Always check with your own physician or medical professional before trying or implementing any information read here.

Noah Quezada is a Registered Dietitian Nutritionist located in Denver, Colorado. Over the course of more than a decade, he has gained extensive experience in helping clients manage their weight through in-person sessions. Noah is also the 2023 President of the Colorado Academy of Nutrition and Dietetics.

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