Illustration of a skinny guy building muscle by dirty bulking.

What Is Dirty Bulking? Are the Results Worth It?

There are countless weapons lifters wield against the skeletal armies of atrophy. One such weapon is the “dirty bulk.” It disregards standard nutritional recommendations, using whatever means necessary to get into a calorie surplus. Usually, that means eating plenty of junk food.

We’ve dirty bulked in the past. We’ve had clients do it, too. Most were everyday people, but some were college, professional, and Olympic athletes. You’d be surprised at what they eat to get into calorie surpluses.

Dirty bulking can be good for building muscle. It won’t necessarily make you fat, either. Some dirty bulkers gain muscle more leanly than some clean bulkers. The Devil is in the details, and we’ll delve into all of those details.

A skinny barbarian bulking up and becoming muscular.

What is Dirty Bulking?

Dirty bulking is when you drive yourself into a calorie surplus by any means necessary, causing weight gain and facilitating muscle growth. Dirty bulkers often rely on junk food because it’s higher in calories and easier on the appetite. That makes it one of the easier ways for skinny guys to gain weight.

Dirty bulking is the opposite of clean bulking. They are the two poles on the “clean eating” spectrum. If the dirty bulker is the beefy powerlifter chowing down on three servings of eggs and bacon, the clean bulker is the ascetic bodybuilder sitting next to him, eating boiled eggs from Tupperware.

Dirty bulking tends to be fairly casual. You follow a generic beginner program, such as Starting Strength. Then you eat big, gain weight, build muscle, and grow gradually stronger. That can work quite well, especially considering how little rigour goes into it. It isn’t ideal, but it’s effective.

Is Dirty Bulking Good for Building Muscle?

Dirty bulking is good for building muscle. The two most important factors for building muscle are stimulating muscle growth with your workout program, then eating enough food to support that growth. Dirty bulking supplies more than enough calories, so if you combine it with a rigorous workout program, you can build a tremendous amount of muscle.

You might be able to build muscle slightly faster by eating a more nutritious diet. We’ll get into that in a moment. The main downside to dirty bulking, though, is that it isn’t very good for anything other than building muscle. You can have a better overall fitness transformation by eating a better diet.

A barbarian wallowing in self despair after bulking up. Illustrated by Shane Duquette.

The Allure of Unrestraint

The dirty bulk is a siren call to indulge your deepest appetites. It liberates you from the shackles of dietary restraint, allowing you to feast wild abandon, fuelling your body’s voracious hunger for growth. If your diet is already good, and if your appetites are reasonable, then it might suit your personality quite well. However, the people most drawn to dirty bulking are often the people least likely to benefit from it.

  • Dirty bulking allows skinny guys to consume more calories more quickly and easily. I was one of those skinny guys. I’ve always had a hard time getting into a calorie surplus. So I piled my plate high with fast food, junk food, grease, and sugar. And it’s true. I gained weight more quickly and easily than ever before.
  • Another supposed advantage of dirty bulking is that it can increase your rate of muscle growth. The logic is that getting into a larger calorie surplus will give your body more of the nutrients it needs to grow, thus speeding up muscle growth. There’s not wrong. Not quite. But you’d build muscle even faster if you ate a more nutritious diet. After all, that would give you even more nutrients.
  • A third purported benefit of dirty bulking is that it allows you to indulge in your favourite foods without feeling guilty. Dirty bulking may seem like a dream come true if you love pizza, burgers, and other high-calorie, high-fat foods. But dreams often become dreamer bulks.

Many skinny guys dive into dirty bulks, build muscle quickly and leanly, and rave about their results. That’s why dirty bulking is so popular. Some guys really do get great results.

The Dark Side of Indulgence

Dirty bulking can cause fat gain. Sometimes. It’s not quite that simple. If you’re naturally skinny, you’ve just started lifting weights, you live a healthy lifestyle overall, and you’re eating in a relatively small calorie surplus, then adding some junk food to your diet probably won’t cause much fat gain (or any other adverse effects).

There are deeper disadvantages to dirty bulking, though:

  • It’s easy to consume too many calories, gain weight too quickly, and gain a disproportional amount of fat. This doesn’t always happen, and some skinny guys are somewhat immune to this problem, but it’s a risk. It’s especially risky for people who naturally tend to overeat.
  • Junk food is often high in saturated fat, which can cause proportionally more visceral fat gain (study). Visceral fat is the unhealthy type of fat that accumulates around your organs. You don’t want to gain more of it.
  • Junk food is often high in sodium. Consuming some sodium is incredibly important. That’s why it tastes so good. However, overdoing it can raise blood pressure in some people (study, study). To make matters worse, your body regulates sodium levels with fluid. Drinking more fluid is hard when your stomach is packed full of food. (I hate being thirsty but not being able to fit any water in my stomach.)
  • A bad diet doesn’t support a robust digestive system. The best way to strengthen your gut microbiome is to eat more whole foods, probiotics, and fibre. Dirty bulkers often eat less of those foods.
  • Dirty bulking can feel bad. You’re more likely to feel tired, bloated, thirsty, and inflamed. That was my experience, anyway.
  • You can develop a bad relationship with food. The joy of indulgence often leads to regret. You might tell yourself it’s okay to eat an entire pizza because you’re dirty bulking, then stress about having overdone it. If you strive to eat a more balanced diet, you might feel better about the path you’re venturing down.
Illustration of a skinny man bulking up to build muscle, transforming into a giant. Illustrated by Shane Duquette.

The biggest downside to dirty bulking, though, is that you miss out on all the benefits of eating an abundant and nutritious diet. A good diet gives us all the nutrients we need to thrive. More protein, fibre, healthy fats, vitamins, minerals, probiotics, and phytonutrients. These nutrients are powerful.

For example, eating more dietary nitrates improves blood flow, giving us better muscle pumps. It’s similar to the benefits guys get from having a pre-workout “pump” supplement—but stronger, and the benefits last longer.

Eating a better diet will give you more energy, support your immune system, help you build muscle faster, deepen your sleep, improve your mood, help regulate your hormones, and make you look and feel younger.

Dirty Bulking Isn’t a Rebound Diet

If you’ve just finished cutting, it’s normal to have food cravings. But the last thing you want to do after going through the immense effort of losing weight is to overindulge, falling right back into your old, unhealthy habits.

My favourite way of escaping the bulk-cut cycle is with reverse bulking. You’d bulk up, keep living a healthy lifestyle, start listening to your appetite again, and let any extra fat fall away. When you’re pleasantly lean again, you can ease back into a calorie surplus. Through all of this, you can eat an abundant and nutritious diet.

Admittedly, our specialty is helping skinny and skinny-fat people bulk up. We aren’t the sort of people who tend to overindulge. This tends to be less of an issue for us.

How to Dirty Bulk

A dirty bulk begins with resistance training. Strength training is common, but we recommend hypertrophy trainingThe whole point of dirty bulking is to gain muscle and strength. Therefore, the first step is to stimulate muscle growth. Hypertrophy training is the best way to stimulate muscle growth.

A muscular man holding a barbell and a dumbbell in his home gym. Illustrated by Shane Duquette.

Then, you need to consume enough calories to gain weightWe’re bulking, after all. We need to eat more energy than we use. We can then use that extra energy to convert dietary protein into muscle tissue.

Try to be active. Try to spend some time on your feet. Go on a 20–40 minute walk every day. If that becomes too easy, try doing cardio 2–4 times per week. This will get your blood flowing, delivering nutrients to your growing muscles. It will also help to ward off visceral fat.

Finally, get enough sleep. Getting enough good sleep can speed up your rate of muscle growth by around 30% while simultaneously reducing the amount of fat you gain. Give yourself at least 7 hours, and maybe as much as 9. If you have trouble falling into a restful slumber, try relaxing or reading by dim light for an hour before bed.

The Best Dirty Bulking Diet

Dirty bulking means eating junk food. I get that. But it’s better to start with a foundation of nutritious whole foods. A stronger foundation will do a better job of supporting any junk food you stack on top of it.

Here are the foods you should build your bulking diet around:

  • Lean meat (chicken, turkey, lean ground beef): meat is an excellent source of protein, which is essential for muscle growth and repair. It’s also rich in micronutrients.
  • Fish (salmon, tuna, tilapia): Fish is another great source of protein, and fatty fish is rich in the omega-3 fatty acids EPA and DHA, which most of us could use more of.
  • Eggs: Egg whites are a complete protein source. Egg yolks are rich in healthy fats and micronutrients.
  • Dairy products (Greek yogurt, kefir, and cheese): Dairy is a great source of protein and calcium, which are important for bone health. They’re also good sources of probiotics, which are good for your digestion.
  • Whole grains and legumes (such as brown rice, corn, quinoa, oats, beans, lentils, and soy): These are fantastic sources of complex carbohydrates, providing sustained energy for workouts, filling our muscles with glycogen, and giving us the energy we need to build muscle. They’re also rich in soluble fibre and many micronutrients.
  • Fruits and vegetables (such as berries, bananas, mangoes, spinach, and broccoli): These provide a wide range of micronutrients, such as vitamins, minerals, and antioxidants. They’re fantastic sources of insoluble fibre, which is great for digestion. They’re also rich in nitrates, which are good for improving muscle pumps and muscle growth.
  • Nuts and seeds (almonds, walnuts, chia seeds): These are nutritious sources of dietary fat, protein, and fibre.
  • Extra-virgin olive and avocado oil: Extra virgin olive oil is great for drizzling on salads and veggies. Avocado oil is great for cooking with.
  • Coffee and tea: These are natural sources of caffeine and rich sources of phytonutrients. Just watch out not to consume them within a few hours of your bedtime, lest they interfere with your sleep.
Before and after photo of someone bulking aggressively, showing that it rivals dirty bulking results.


Dirty bulking is a double-edged sword. When wielded with purpose and tempered by discipline, it can help you build muscle quickly and easily. Yet, when used with reckless abandon, it can weigh you down with fat. It’s a risky endeavour. I’ve done it, but I don’t recommend it and wouldn’t do it again. There are better ways to bulk up.

If you want to build muscle quickly, a better approach is to bulk aggressively. Follow a good hypertrophy training program, eat a nutritious diet, gain weight as fast as you like, build a ton of muscle, and gain even more strength.

Photo showing the Bony to Beastly Bulking Program for Skinny and Skinny-Fat Guys

Alright, that’s it for now. If you want to know the ins and outs of bulking up, we have a free newsletterIf you want a full muscle-building program, including a 5-month workout routine, a bulking diet guide, a gain-easy recipe book, and online coaching, check out our Bony to Beastly Bulking Program. Or, if you want a customizable intermediate bulking program, check out our Outlift Program.

Shane Duquette is the founder of Outlift, Bony to Beastly, and Bony to Bombshell, each with millions of readers. He's a Certified Conditioning Coach (CCC), has gained seventy pounds, and has over a decade of experience helping more than ten thousand naturally thin people build muscle. He also has a degree in fine arts, but those are inversely correlated with muscle growth.

Marco Walker-Ng is the founder and strength coach of Outlift, Bony to Beastly, and Bony to Bombshell. He's a certified trainer (PTS) and nutrition coach (PN) with a Bachelor's degree in Health Sciences (BHSc) from the University of Ottawa. He has over 15 years of experience helping people gain muscle and strength, with clients including college, professional, and Olympic athletes.

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