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

If you are embarking on a weight gain journey, then you have probably toyed with doing a dirty bulk. 

A dirty bulk consists of eating very high calorically dense foods, and while it can be fun to “eat whatever you want”, many people wonder how long you should eat like this before reigning in your diet.  

As a nutrition coach, my answer is: 

If immediate weight gain is desired, a 1-week dirty bulk can be a great tool since it will provide a calorie surplus that can contribute to strength and muscle growth. However, a dirty bulk can lead to unwanted fat gain, feelings of sluggishness, and poor health outcomes (high cholesterol levels) if done long-term.

So today, I give you everything you need to know about doing a 1-week dirty bulk, including: 

  • 3 reasons to do a 1-week dirty bulk
  • What your current state should be before starting a 1-week dirty bulk
  • How to do a 1-week dirty bulk properly
  • Results you can expect from a 1-week dirty bulk
  • What you should do after a 1-week dirty bulk

What Is A 1-Week Dirty Bulk?

A 1-week dirty bulk consists of intentionally eating in a calorie surplus, typically consuming at least 500 calories over your normal maintenance calories (with no upper limit on calories) per day.  

This is done by eating any type of food including “junk food” and highly processed food. 

A 1-week dirty bulk will also include plenty of resistance training to promote muscle growth rather than fat gain (even though some fat gain while dirty bulking is inevitable).

3 Reasons To Do A 1-Week Dirty Bulk

Pros vs Cons of a 1-week dirty bulk

 The 3 reasons you might want to do a 1-week dirty bulk are: 

1. It Can Give You Quick Strength Gains in the Gym

If you have been struggling to make any strength gains in the gym, then a 1-week dirty bulk could be the trick. 

When you are eating in a calorie surplus, your body has more energy (mainly from carbohydrates) to use as fuel when you are working out. This can increase your performance and strength in the gym.

2. It Can Serve as a Mental Break From Dieting

One of the biggest reasons someone chooses a dirty bulk over a clean bulk is that it is relatively stress-free since it does not require that you pay close attention to calorie and macronutrient intake. 

Not only that, but during a dirty bulk, no foods are off limits, which can provide a much-needed mental break from your regular diet.

3. You Can Put on a Lot of Weight Very Quickly

For certain individuals who have a very difficult time putting on weight (hard gainers), then doing a short-term dirty bulk where you try and consume as many calories as possible could be beneficial. 

Of course, not all of the weight gained during a dirty bulk will be contributed to muscle, but for those who struggle to put on any weight at all, consuming a large number of calories may be the most effective way to put on muscle.

What Your Current State Should Be Before Starting a 1-Week Dirty Bulk

Before starting a 1-week dirty bulk, you should ensure that: 

1. You Are Relatively Lean

If you are going into a 1-week dirty bulk, chances are it is because you have a hard time putting on weight. 

Dirty bulking is popular amongst those who consider themselves to be “hard gainers” (people who have a hard time putting on weight) since a significant calorie surplus usually leads to weight gain.

However, if you are someone who already has a significant amount of body fat, doing a dirty bulk is probably not going to benefit you, since it is likely that you will put on even more body fat, which you will then have to work to get off through a calorie deficit.

For this reason, a 1-week dirty bulk is typically only going to be beneficial for someone who does not have high body fat (25% or more for men, or 30% or more for women), or a difficult time putting on weight.

2. You Have a Healthy Relationship With Food

Doing a dirty bulk for 1 week can be a great way to have a mental break from your diet. This is particularly true if you usually follow a strict diet that does not allow for any high-calorie or processed foods.

However, if you find that you struggle with controlling yourself around foods that you don’t normally allow yourself, or you find that you are prone to binge eating type behaviors, then a 1-week dirty bulk is not for you.

Instead, I recommend a more structured bulking phase, where you consume a balanced amount of both whole foods that are rich in nutrients, and high-calorie processed foods that you enjoy.

3. You Are in Good Health

If you are someone who has struggled with health conditions such as high cholesterol levels, or elevated blood sugar, then doing a dirty bulk, even for 1 week could make these issues worse. 

For this reason, it is a good idea to make sure you are in good health before a dirty bulking phase. 

A great step to take prior to starting your 1-week dirty bulk is to visit your doctor and run some blood tests for health markers such as your cholesterol levels, blood pressure, and nutrient levels.

You could even plan to recheck these markers after your dirty bulk to note any changes.

How To Dirty Bulk For A Week: 4 Steps

How to dirty bulk for a week 4 steps

If you are going to embark on a 1-week dirty bulk, here is a list of steps that you can follow to ensure you are doing it properly: 

Step #1: Determine a minimum number of calories that you want to hit daily

To be successful in any bulking phase, you must ensure that you are in a calorie surplus. More specific to a dirty bulk, the goal is to eat as many calories as possible, no matter what the food source is.

Therefore, your first step would be to determine your maintenance calories and then calculate the minimum number of calories you will aim to hit a day to be in a calorie surplus

While a calorie surplus can be as little as 250 calories to see weight gain, you will want to be eating much more than this during your 1-week dirty bulk.

My recommendation during your 1-week dirty bulk is to aim for a minimum of 500 calories above your maintenance intake, since a 500 calorie surplus for 7 days is the minimum number of calories needed to gain 1 pound. 

However during a dirty bulk, it is not unheard of to consume a few thousand calories above your normal maintenance intake. 

Therefore, while it is important to pay attention to the minimum amount of calories you consume, there is no upper limit to how many calories you consume during a dirty bulk.

To determine your maintenance calories, you can use an online calculator to determine your Total Daily Energy Expenditure, such as this one here.

For example, a 175-pound male athlete with a maintenance calorie intake of 2500 calories per day would need to ensure his calorie intake is at the very least 500 calories above this (i.e. eating 3000+ calories per day).

Note: While a dirty bulk is meant to be less calculated with more freedom, I would loosely track your calories for the first day or two, just to make sure that you are well above your maintenance calories.  

Step #2:  Calculate your protein intake

If you aim to put on as much muscle mass as possible during your dirty bulk, then it will be worthwhile paying attention to your protein intake. 

While you don’t need to be tracking your macronutrients meticulously, it’s good to have a rough idea of how much protein you are eating.

During a bulking phase, I recommend getting roughly 30-35% of your total calories from protein-rich foods. 

For example, if you’re eating roughly 5000 calories per day during a dirty bulk, this would equal about 375-437 grams of protein per day.

Note: Keep in mind that during a dirty bulk it is not required that you pay attention to protein intake, however eating an adequate amount of protein paired with resistance training will help to increase the amount of muscle mass you put on during your bulking phase.

Step #3:  Have a rough idea of what foods you will eat during the week

Knowing what foods are best to eat during a dirty bulk will help to increase the likelihood of your success. While no foods are technically off limits, there are going to be foods that are more optimal compared with others during your 1-week dirty bulk.

For example, when you are dirty bulking, some foods that you might want to avoid are sugar-free foods, along with low-calorie or diet food items. 

While you can still eat whole foods while you are dirty bulking, it is best not to fill up on foods that are low in calories and high in fiber, since this will make it more difficult to hit your calorie surplus.

If you have been craving particular foods or meals that are high in calories and not normally part of your diet, your 1-week dirty bulk is a great time to indulge in these. 

Some examples of foods that you might include in your dirty bulk are:

  • Pizza
  • Creamy pasta dishes
  • Baked goods such as cookies, cupcakes, muffins
  • Cheeses
  • Fast food
  • Nuts and nut butter
  • High-calorie fruits and vegetables (such as dates, and avocado)
  • Eggs
  • High-calorie animal protein (bacon, fattier cuts of red meat and poultry)
  • Mass gain powders

Step #4:  Take photos and weight every day to note changes in physique

During your 1-week dirty bulk, it would be beneficial to take photos of your physique at the same time every day for you to log any physical changes. 

It is best to take these photos in the morning, wearing similar clothing in each photo to allow for easy comparison.

In addition to this, you can weigh yourself at the same time every day (preferably in the morning before eating or drinking anything) to make sure you are gaining weight. 

Results You Can Expect from Dirty Bulking for a Week

After a week of dirty bulking, as long as you have been in a consistent calorie surplus, you will almost certainly notice your weight increase. 

However, this weight increase could be from water retention, fat gain, muscle growth, or a combination of all three.

For example, if you have been eating at a minimum of a 500 calorie surplus, you could expect to gain around 1-5 pounds, depending on how much water your body retains. 

For example, in Rob Nerland’s dirty bulk experiment, he gained a total of 6.3 pounds in 12 days. According to his measurements where the most significant growth was seen in his stomach, it is likely that the majority of the weight he gained was from water retention.

Results from short-term dirty bulking experiment

Since every gram of carbohydrate in the body has 3-4 grams of water attached to it, an increase in carbs means an increase in water weight.

While the weight increases seen from water retention are only temporary, they will still contribute to the increased number that you see on the scale at the end of your 1-week dirty bulk.

Are There Any Downsides to a 1-Week Dirty Bulk?

While it is unlikely that you will do any serious damage with a dirty bulk only lasting for 1 week, there are a few downsides that you will likely notice.

Fat Gain

One of the most notable downsides of a dirty bulk is that it can encourage unwanted fat gain

For obvious reasons, eating an unlimited number of calories where no foods are off limits is likely to result in some fat gain in addition to any muscle mass gained.


In addition to this, a common side effect of following a dirty bulking diet is feelings of sluggishness and lethargy, brought on by eating foods that are high in ingredients such as sodium, refined sugars, and other additives that might disturb digestion.

Foods that are typically included in a dirty bulk commonly have a high amount of fat, which can also contribute to problems with digestion.

Negative Health Outcomes

Lastly, following a dirty bulk, even for a short period, can have negative effects on your health

Eating processed foods that are high in processed sugar, saturated and trans fats has been shown to increase your risk of certain health conditions like diabetes, cancer, and high blood pressure. 

Not only this, but if you are eating food that lacks essential vitamins and minerals found in whole foods, you could end up noticing a decrease in your immune health.

With that said, it is unlikely that dirty bulking for 1-week will do any damage that can’t be reversed by simply going back to eating nutritious whole foods. 

Should You Do A 1-Week Dirty Bulk:  My Recommendation

My recommendation is if your goal is to put on muscle, you are better off doing a more calculated clean bulk since muscle gains can likely be achieved as long as you are in an adequate calorie surplus.

Following a more calculated bulk consisting of less processed foods will not only help to mitigate the risk of putting on excess body fat, but it will also likely ensure better energy levels and digestion since you will be eating more nutritious foods that will not make you feel heavy or sluggish.

However, if you are someone who has a difficult time gaining weight and you have tried doing a clean bulk in the past, then experimenting with a 1-week dirty bulk might be right for you. 

With that said, due to the potential long-term health effects of a dirty bulk, I would not recommend exceeding more than a week or two of this type of diet at a time.

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

After a 1-week dirty bulk, the best thing to do would be to taper back down to your maintenance calories and return to your previous macronutrients.

 After a week of indulging in calorie-dense processed foods, it is best to return to eating a diet that consists mostly of whole foods that are dense in nutrients.

Other Bulking Resources


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Stinson, E. J., Piaggi, P., Ibrahim, M., Venti, C., Krakoff, J., & Votruba, S. B. (2018). High Fat and Sugar Consumption During Ad Libitum Intake Predicts Weight Gain. Obesity (Silver Spring, Md.), 26(4), 689–695. https://doi.org/10.1002/oby.22124

Chan ST, Johnson AW, Moore MH, Kapadia CR, Dudley HA. Early weight gain and glycogen-obligated water during nutritional rehabilitation. Human nutrition. Clinical Nutrition. 1982 ;36(3):223-232. PMID: 6811511.

Forouhi, N. G., Misra, A., Mohan, V., Taylor, R., & Yancy, W. (2018). Dietary and nutritional approaches for prevention and management of type 2 diabetes. BMJ (Clinical research ed.), 361, k2234. https://doi.org/10.1136/bmj.k2234

Fiolet, T., Srour, B., Sellem, L., Kesse-Guyot, E., Allès, B., Méjean, C., Deschasaux, M., Fassier, P., Latino-Martel, P., Beslay, M., Hercberg, S., Lavalette, C., Monteiro, C. A., Julia, C., & Touvier, M. (2018). Consumption of ultra-processed foods and cancer risk: results from NutriNet-Santé prospective cohort. BMJ (Clinical research ed.), 360, k322. https://doi.org/10.1136/bmj.k322

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.

Iraki J, Fitschen P, Espinar S, Helms E. Nutrition Recommendations for Bodybuilders in the Off-Season: A Narrative Review. Sports (Basel). 2019 Jun 26;7(7):154. doi: 10.3390/sports7070154. PMID: 31247944; PMCID: PMC6680710.

About The Author

Colby Roy

Colby Roy is a holistic health and nutrition coach. She is certified through Precision Nutrition and has a passion for all things nutrition and healing the body. More specifically, Colby likes to work with clients who want to optimize their gut health and energy levels.

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