Dirty Bulking For A Month: How To Structure + What To Expect

As a nutrition coach, I’ve guided many of my clients through a one-month dirty bulk so I know what you can realistically expect from a dirty bulk and what you need to do to be successful.

So, should you dirty bulk for a month? Dirty bulking for a month is a great way to gain a lot of muscle mass quickly, but there is an associated increase in body fat that comes with it. If your goal is to gain as much weight as possible as quickly as possible and you’re okay with an increase in fat mass, then dirty bulking for a month can be a good idea.

Before committing to a dirty bulk, it’s important to weigh out the pros and cons to see if you’re ready to commit to the process because a dirty bulk certainly isn’t for everyone.

After reading this article, you’ll learn:

  • What a 4-week dirty bulk is
  • Four reasons why you might want to do a month-long dirty bulk
  • How to do a dirty bulk for a month
  • Results you can expect from a 4-week dirty bulk
  • The downsides of dirty bulking for a month

What Is A 4-Week Dirty Bulk?

A 4-week dirty bulk is where you spend four weeks aggressively trying to gain weight by lifting weights consistently and eating at a high caloric surplus (i.e. eating far more calories than you burn each day). This is often accomplished by eating high-calorie foods usually seen as “unhealthy” or “dirty.”

While athletes and lifters typically try to limit their consumption of foods like pizza, cheeseburgers, and ice cream most of the year, during a 4-week dirty bulk, these foods are eaten regularly for the sole purpose of gaining as much weight as possible.

The goal of a dirty bulk is to gain a lot of weight quickly. Dirty bulks often lead to an increase in muscle mass, but because of the large caloric surplus required, there is an associated increase in fat mass as well.

4 Reasons To Do A 4-Week Dirty Bulk

You should consider a 4-week dirty bulk if you:

  • Need to gain weight for a specific sport
  • Want to get as big as possible
  • Struggle to put on weight
  • Have plateaued with your lifts

1. Need To Gain Weight For A Specific Sport

One of the main reasons that people are interested in dirty bulking is to be more competitive in their sport. If you are a football player, Olympic weightlifter, or powerlifter, you may be in a position where you need to gain weight to advance in your sport.

For sports like football, your performance may improve simply by having more total mass to block another player. For weight class sports like weightlifting and powerlifting, perhaps you’ve maxed out your potential at a lower weight class and you need to gain weight quickly to be more competitive in a higher weight class at an upcoming meet.

In these situations, it is often irrelevant if you add fat mass along with muscle mass, so a 4-week dirty bulk is the best option to further your performance in your sport.

2. Want To Get As Big As Possible

If your goal is to get as big as possible and you don’t care about having six-pack abs or veins popping out of your arms, then a 4-week dirty bulk is a great option for you. 

A one-month dirty bulk will help you to get as big as possible relatively quickly because, if done correctly, you will be in a large calorie surplus (eating much more than you need to maintain your weight).

Your body will use this calorie surplus to build muscle, and the calories not used for muscle growth will be stored as fat for later use. Both fat and muscle gain will help you look as big as possible.

3. Struggle Greatly To Put On Weight

Another reason you should consider dirty bulking is if you struggle to gain weight because dirty bulking will help you take your calorie surplus to the next level.

Hardgainers (those who have a hard time gaining weight) may not be able to gain weight without pushing themselves to a more extreme form of bulking because of their fast metabolisms (they burn calories at a faster rate).

For example, if you’re eating 3000 calories per day of lean meats, high-fiber carbs, and fruit and veggies then you will likely feel incredibly full and find it difficult to eat more. However, if you bulk with “dirtier” foods like pizza and burgers then you could easily eat 5000 calories without reaching that same level of discomfort.

An aggressive 4-week dirty bulk, combined with an appropriate high-volume mass-gaining weightlifting program, may be the only way for these individuals to gain weight and spark long-overdue muscle growth.

4. Plateaued With Your Lifts

If your squat, bench, deadlift, or other lifts haven’t progressed in a while then you may have reached a plateau. A month-long dirty bulk may be exactly what you need to break through this plateau and continue getting stronger.

A dirty bulk can help you progress in the gym because it will help you add mass, and more mass helps you to move bigger weights.

  • Related Article: 1-Week Dirty Bulk – Check out this article if you think a 1-month dirty bulk is too long

What Your Current State Should Be Before Starting A 4-Week Dirty Bulk

The ideal state to be in before starting a 4-week dirty bulk is to have a lower body fat percentage because you will gain less fat overall and have more potential for muscle growth; however, those starting with a higher body fat percentage can still benefit from a dirty bulk.

If you’re already fairly lean when you start a 4-week dirty bulk (10% body fat or less for a male, 15% body fat or less for a female), you will not see as much fat gain as you would if you entered at a higher body fat percentage. 

This is because obese and overweight individuals tend to put on a larger proportion of fat than those who are leaner when in a caloric surplus (eating more calories than your body needs to maintain weight).

However, being lean isn’t a requirement for you to begin dirty bulking. Those who don’t have lower body fat percentages can still benefit from a dirty bulk if they want to be more competitive in their sport or get as big as possible.

The only reason that you wouldn’t benefit from a dirty bulk based on your current state is if you have pre-existing health conditions such as high blood pressure or high cholesterol, which could worsen with a dirty bulk.

How To Dirty Bulk For A Month

how to dirty bulk for a month

Dirty bulking for a month is incredibly simple as long as you follow these steps:

Step 1: Eat As Much As You Can

There is no need to track anything, no need to avoid certain foods (including sugar), and no need to feel any guilt when dirty bulking. One of the benefits of a dirty bulk is that you can ease up on measuring and tracking and simply take time to enjoy the foods that you typically wouldn’t consume.

When I was desperately trying to gain weight for football in high school, I would walk to McDonald’s every day during the summer for a meal between lunch and supper. As a 130-pound middle linebacker, I needed to gain weight and wasn’t too concerned about how much of it was fat. This is the mindset needed for a successful dirty bulk – your hobby is eating.

If you’re committing to the 4-week dirty bulk you shouldn’t have a problem consuming enough calories to gain mass. That said, it’s common for people to think they’re consuming more calories than they actually are.

If you aren’t seeing results on the scale, then it might be worth tracking for a few days to ensure you’re eating enough. For reference, you should aim to eat at least 1,000 calories more than your maintenance calories each day.

For example, if you maintain your weight by eating 2500 calories per day then you should aim to consume 3500 calories per day while dirty bulking.

Step 2: Track Your Progress

The best tool for measuring the success of a 4-week dirty bulk is the scale.

I like having my clients weigh themselves daily during a 4-week dirty bulk for two reasons:

  1. If the scale isn’t going up, it causes them to eat even more than they already are (which helps them progress). 
  1. If the scale is going up, it’s motivating and encourages them to continue to follow the plan.

Additionally, tracking the arm, chest, and thigh girth can be beneficial. Sometimes we don’t notice our arms or legs getting bigger as it can happen gradually, but by measuring them every week, we can see exactly how much we’ve grown.

I’m not, however, a fan of taking pictures during a dirty bulk. Before and after pictures are a great idea, but taking pictures during the 4-week dirty bulk can cause people to lose sight of the goal

In fact, when I have a client going through a 4-week dirty bulk, I don’t even want them looking in the mirror as often as they normally would because the loss of definition and/or increase in body fat can scare them and cause them to abandon their initial goal.

Looking in the mirror or taking pictures during a 4-week dirty bulk is kind of like testing your half-marathon time when training for a powerlifting meet – pointless and detrimental to the goal.

Step 3: Lift Weights At Least Three Times A Week

To make the most of your 4-week dirty bulk, you should lift weights at least three times a week.

If you focus on big, compound exercises like the squat, deadlift, and bench press and lift heavy weights for sets of 3-12 repetitions, you will gain more muscle mass. 

If you do not lift weights consistently while dirty bulking, then most of the mass you gain will be fat because you won’t be giving your body a reason to build more muscle mass.

Results You Can Expect From Dirty Bulking For A Month

After dirty bulking for a month, you can expect that you will be noticeably bigger and stronger. It’s common to see increases of over ten pounds after a four-week dirty bulk, which can be attributed to gains in both fat and muscle mass.

The amount of fat that you will gain after a month will depend on how many calories you eat per day, which you won’t be aware of unless you track your intake. For reference, you would have to eat approximately 3500 calories above your maintenance calories to gain a single pound.

Your potential to gain muscle though is more predictable. Men are likely to gain between 0.4 to 2.5 lbs of muscle per month and women 0.2 to 1 lb of muscle mass per month (on the lower end if well-trained in the gym, on the higher end for beginners).

Therefore, if you gain 10lbs from your one-month bulk it’s fair to expect at most 2.5lbs (men) or 1lb (women) of muscle gain. This also means that of the 10lbs gained, you could expect a minimum of 8.5lbs (men) or 9lbs (women) to be fat gain.

You may also move a little slower and see your endurance decrease immediately after your dirty bulk, but over time you’ll become more accustomed to your new physique and return to a more normal diet, which will allow you to move and feel better.

Are There Any Downsides To A 4-Week Dirty Bulk?

There are three main downsides to a 4-week dirty bulk:

  • You will gain fat
  • There are potential health consequences
  • Your endurance will take a hit

1. You Will Gain Fat

You will absolutely gain fat during a 4-week dirty bulk, so if you do not want to gain excess body fat while bulking, then a dirty bulk is not your best option. This is a major drawback for those who are not ready to commit to putting on higher amounts of fat mass.

If you’d rather try a form of bulking that’s more likely to lead to gains in lean mass rather than fat mass, you should pursue a lean bulk instead. A lean bulk involves a smaller caloric surplus to limit fat gain while working to build muscle.

2. There Are Potential Health Consequences

Eating a large amount of high-calorie, low-nutrient, ultra-processed foods is associated with a higher risk of cardiovascular, coronary heart, and cerebrovascular diseases. Any time you are consuming excessive amounts of ultra-processed foods, the risk of these health conditions increases so it’s important to be aware of the risks.

Additionally, putting on large amounts of fat can be a health risk by itself especially if you’re going into a dirty bulk at a higher body fat percentage. Higher body fat percentages have been linked to an increase in joint and soft tissue pain, as well as higher levels of inflammation.

A 4-week period of eating less nutrient-dense foods likely isn’t a concern for otherwise healthy individuals, but if you have a pre-existing health condition or have a higher risk for health conditions then you may want to reconsider your dirty bulk.

3. Your Endurance Will Take A Hit

A 4-week dirty bulk is all about getting big and strong, and this usually comes at the cost of your endurance.

It may take you longer to recover between sets, and you might find yourself winded after walking up a few flights of stairs. But if your goal is to get bigger, a temporary loss of endurance is the price you have to pay.

Should You Do A 4-Week Dirty Bulk? My Recommendation

If you are a competitive athlete that requires added mass to excel in your sport, if you are struggling greatly to add meaningful mass, or if your lifts in the gym have stagnated for two months or longer, then I would recommend dedicating a month to getting bigger and stronger by doing a 4-week dirty bulk.

Yes, you will gain fat with a 4-week dirty bulk, but if you need to get bigger to reach your goals more quickly then it’s worth it. So commit yourself to gain as much mass as possible for a month and enjoy the dirty-bulk lifestyle.

The only time I wouldn’t recommend a 4-week dirty bulk is for those who have pre-existing health conditions or those at a higher risk of developing health conditions because it’s not sacrificing your health.

What Should You Do After Your 1-Month Dirty Bulk?

After a month-long dirty bulk, you should return to a maintenance-level caloric intake and re-introduce nutrient-dense healthy foods back into your diet. Follow these steps:

1. Decrease Caloric Intake

After your month-long dirty bulk, you’ll want to bring your daily caloric intake back down to a more normal level. You can do this by finding how many calories you should eat to maintain your new weight, then tracking and measuring your food to stay on target with this intake for at least 2 weeks.

It’s important to note that the number of calories you ate to maintain your weight before your bulk will not be the same after your bulk. 

This is because when you were bulking you likely added some muscle mass (which requires more calories to maintain), so you will likely need more calories to maintain your weight now than you did before the bulk.

For example, if you maintained your weight by eating 2000 calories before perhaps after bulking you’d maintain your weight by eating closer to 2500 calories.

2. Increase Fruit and Vegetable Intake

Fruits and vegetables will likely be limited during a 4-week dirty bulk because they are low in calories and fill up your stomach too quickly, so they aren’t a priority. However, once the bulk is over it is vital you make them a priority because they’re important for your overall health.

Consider the 2 weeks after your bulk time spent catching up on nutrients that you may have been lacking while you were enjoying less nutrient-dense foods. 

3. Avoid Going On An Extreme Diet

After a month-long dirty bulk, it’s important to get back into a more normal eating routine, but there’s no need for restrictive dieting. 

If you’ve reached a level of fat gain that is uncomfortable for you while dirty bulking, then after spending 2 weeks at maintenance you could try a more conservative cut to shed some fat while retaining the muscle you’ve gained.

What you need to avoid is going from one extreme (eating as much as possible) to another (heavily restricting your intake) because that is textbook yo-yo dieting and can cause serious health and weight issues.

What To Read Next:


Evangelista, A. L., Braz, T. V., La Scala Teixeira, C. V., Rica, R. L., Alonso, A. C., Barbosa, W. A., Reis, V. M., Baker, J. S., Schoenfeld, B. J., Bocalini, D. S., & Greve, J. M. D. (2021). Split or full-body workout routine: which is best to increase muscle strength and hypertrophy?. Einstein (Sao Paulo, Brazil), 19, eAO5781. https://doi.org/10.31744/einstein_journal/2021AO5781

Forbes GB. Do obese individuals gain weight more easily than nonobese individuals? Am J Clin Nutr. 1990 Aug;52(2):224-7. doi: 10.1093/ajcn/52.2.224. PMID: 2197850.

Campos GE, Luecke TJ, Wendeln HK, Toma K, Hagerman FC, Murray TF, Ragg KE, Ratamess NA, Kraemer WJ, Staron RS. Muscular adaptations in response to three different resistance-training regimens: specificity of repetition maximum training zones. Eur J Appl Physiol. 2002 Nov;88(1-2):50-60. doi: 10.1007/s00421-002-0681-6. Epub 2002 Aug 15. PMID: 12436270.

Srour B, Fezeu LK, Kesse-Guyot E, Allès B, Méjean C, Andrianasolo RM, Chazelas E, Deschasaux M, Hercberg S, Galan P, Monteiro CA, Julia C, Touvier M. Ultra-processed food intake and risk of cardiovascular disease: prospective cohort study (NutriNet-Santé). BMJ. 2019 May 29;365:l1451. doi: 10.1136/bmj.l1451. PMID: 31142457; PMCID: PMC6538975.

Walsh, T. P., Arnold, J. B., Evans, A. M., Yaxley, A., Damarell, R. A., & Shanahan, E. M. (2018). The association between body fat and musculoskeletal pain: a systematic review and meta-analysis. BMC musculoskeletal disorders, 19(1), 233. https://doi.org/10.1186/s12891-018-2137-0

Contreras, R. E., Schriever, S. C., & Pfluger, P. T. (2019). Physiological and Epigenetic Features of Yoyo Dieting and Weight Control. Frontiers in genetics, 10, 1015. https://doi.org/10.3389/fgene.2019.01015

About The Author

Riley Nadoroznick

Riley Nadoroznick is a strength, conditioning, and nutrition coach and the owner of Conviction Fitness.

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