Dirty Bulk Vs. Clean Bulk: Which One for Muscle Mass?

Bulking entails consuming a calorie surplus to boost weight and increase muscle mass, but there is more than just one way to do this.

If you’ve considered bulking, you may have heard of the terms “dirty bulk” and “clean bulk” but what’s the difference? And what should you be doing?

What Is A Dirty Bulk? 

A dirty bulk is when you throw caution to the wind and consume an excess of calories without any focus on quality. The goal of dirty bulking is to gain as much weight as you can in a short period of time to boost muscle gain.

Pros Vs. Cons 

While a dirty bulk sounds easy, who wouldn’t want to eat whatever they want without concern? It’s not without its drawbacks.

A dirty bulk is easy, allows for a lot of freedom, and often causes a rapid uptick in weight in a brief period. However, a dirty bulk also yields less favorable results in terms of muscle growth.

Because quality of intake is not considered during a dirty bulk, but rather just the increase in calories, an increase in fat gain along with muscle gain is likely [1]. 

Dirty bulking can also lead to alterations in certain lab values, such as cholesterol and blood sugar levels. This can increase the risk of developing certain health conditions such as heart disease and type 2 diabetes [2, 3].

However, if this is done over a short period, these lab values will likely improve when going back to an unprocessed diet.

What Is A Clean Bulk?

A clean bulk takes a more intentional approach to building muscle mass without just taking in a calorie surplus. A clean bulk entails a 10-20% calorie surplus with a target protein range of 1.6-2.2 grams per kilogram of body weight [4].

This is achieved by consuming whole, unprocessed foods such as lean meats, healthy fats from sources such as avocados, nuts, seeds, high-fiber carbs, and plenty of fruits and vegetables while limiting or avoiding processed food items.

Pros Vs. Cons 

A clean bulk can help to better target muscle gains without any excess fat gain. It may also help to boost nutrition and prevent any negative health conditions.

However, a clean bulk can be more difficult for some to do as it entails a more strict dietary approach. It also takes longer than a dirty bulk because you aren’t boosting your calorie surplus as quickly and it is not as flexible. This can make it challenging for some to sustain.

Dirty Vs. Clean Bulk: Which Is Better For Muscle Mass? 

Whether you decide to dirty bulk or clean bulk, both are associated with an increase in muscle mass when combined with regular strength-based training. 

Dirty bulking will lead to increases in muscle mass faster however, clean bulking will lead to less fat gain and more intentional muscle gain. 

If your goal is to rapidly increase muscle, you may choose to use a dirty bulk; however, in the long run, a clean bulk will provide more benefits toward high-quality muscle gains.

Dirty Vs. Clean Bulk: Which Is Better For Body Recomposition? 

During body recomposition, you are focusing on decreasing fat mass and increasing lean body mass. 

Because clean bulking focuses on a slow and steady increase in calories leading to muscle growth and decreased fat gains, it will be a better choice for those leaning towards body recomposition compared to dirty bulking.

Which Is Better For Increasing Strength? 

With a dirty bulk, you will have a more rapid increase in muscle mass however, you may see better strength gains overall with a clean bulk. 

Both will yield similar results in muscle mass however, the increase in strength depends more on your exercise routine. A clean bulk may have better influences on performance due to dietary advantages compared to a dirty bulk which can lead to better strength gains [5, 6].

Which Is Better For Exercise Endurance? 

Additionally, a clean bulk will likely be better for endurance improvements compared to a dirty bulk due to the higher diet quality. 

If you are doing a dirty bulk and consuming a calorie surplus of highly processed food items, you may find yourself sluggish and struggling to perform endurance activities as you have not fueled your body to excel in that type of exercise.

When you choose a clean bulk, you are emphasizing proper nutrition for muscle gain which can also benefit exercise endurance as you are choosing high-quality carbs for your energy source such as whole grains, beans, legumes, fruits, and veggies whereas a dirty bulk is likely lacking these foods [7].

Which Is Better For The Gut? 

A nutrient-rich diet also compliments gut health which puts a clean bulk at an advantage in this area as well. Heavily processed food items can wreak havoc on your gut microbiome and these can be found in large amounts on many dirty bulk diets as nutrient composition is not taken into consideration [8]. 

Mass-Building Shake Recipe 

If you’re looking to bulk, whether clean or dirty, below is a mass-building shake recipe that will work for either option but keep in mind that a clean bulk tends to be the better option for health and physical performance compared to a dirty bulk.

Chocolate PB Banana Mass-Building Shake

Serves 1


  • 4 scoops weight gainer protein 
  • 2 tbsp of peanut butter
  • 1 frozen banana
  • ½ avocado
  • Large handful of fresh spinach 
  • 8-10 ounces of milk of choice
  • Ice as needed 


Blend all ingredients in a high-powered blender until smooth. Add ice as needed to reach the desired consistency.