Clean Bulk vs. Dirty Bulk: Which Is Best for Building Muscle?

When your primary goal is to build muscle mass, the path to success is fairly straightforward: increase calorie intake so you consume more than you expend (i.e. eating more calories than you burn) and resistance training several times per week. Yet, the longstanding debate over the advantages and disadvantages of a "clean bulk" vs. "dirty bulk" approach adds another layer of complexity to the situation.

So, what is "clean bulking" exactly? How does it differ from its unkempt counterpart, "dirty bulking"? Sarcasm aside, this article will give you a better understanding of these methods and how to decide which side of the spectrum to lean on for maximizing muscle gain while avoiding excessive fat gain. (Hint: The "best" option probably lies somewhere in the middle.)

What Are "Dirty Bulking" and "Clean Bulking"?

At its core, a "bulking diet" is a nutritional strategy to achieve an energy/calorie surplus; an excess of energy is a requisite for muscle growth, a process termed "muscle hypertrophy" in scientific parlance. This attribute is common to both "clean" and "dirty" bulking diets. However, these diets significantly diverge when it comes to food selection.

"Clean bulking" is a dietary paradigm that emphasizes eating "clean foods" to promote muscle gain and limit fat gain. The goal is not only to consume more calories than your body burns but to acquire these surplus calories from nutritient-dense foods (e.g. lean meats, whole-grain carbohydrates, and fresh vegetables). The sentiment of "clean bulkers" is to increase muscle mass without concurrently adding an excess of body fat. Hence, those opting for clean bulking abide by strict dietary guidelines, usually underpinned by stringent meal planning and preparation.

In stark contrast, the philosophy of "dirty bulking" entails a more "carefree" methodology. liberal approach. It tolerates, even encourages, the consumption of food items that are high in calories yet lacking meaningful nutritional value - fast food, sugary snacks, and processed meals.

While clean bulkers might painstakingly count every calorie, dirty bulkers are primarily concerned with ensuring they consume a surplus of calories, under the simplified rationale that more calories typically correspond to more muscle growth. This practice appears easier, considering the relaxed dietary restrictions, but it runs the risk of accumulating unhealthy levels of body fat and can potentially harm overall health. 

We should note that "dirty bulk(ing)" and "clean bulk(ing)" are not scientific or technical terms; they are colloquialisms originating from bodybuilding subculture.

Clean Bulk vs. Dirty Bulk: How They Both Get it Wrong

The total number of calories and macronutrients you consume is ultimately what dictates energy balance and, therefore, weight loss or weight gain. However, that doesn't mean that all foods with equal macros and calories elicit the exact same physiological response. For example, eating 50 grams of pure table sugar (sucrose) won't have the same influence on muscle protein synthesis as 50 grams of pure protein.

People tend to get carried away with the dirty bulk approach and completely overlook the nutritional qualities of food (because foods nourish us with more than just calories). On the other hand, clean-bulking advocates may latch onto an obsessive control over food intake and only eating foods that are considered "healthy" or "clean."

But that's good though, right? You can't have too much of a "good" thing, can you?

Actually, yes—everything you consume has a "healthy" dose and an "unhealthy" (or toxic) dose, including food. Before you take this revelation and decide it's time to "dirty bulk" your way to the promised land, remember that eating mostly lean proteins, complex carbohydrates, quality fat sources, fibrous vegetables, and fresh fruits is a natural ramification of meeting proper macronutrient and micronutrient quotas for overall wellbeing and muscle growth.

But notice the adjectives "clean" and "healthy" aren't being used to describe those foods; rather, they are "nutrient-dense" foods (the opposite of "empty-calorie"). 

Now, does this mean your bulking meal plan should consist of nothing but chicken breast, rice, and broccoli? Of course not. There is a middle-ground here if you know how to control your portion sizes. You can certainly enjoy a piece of pie or a few Oreo cookies from time to time while achieving your muscle-gain goals (and limiting body-fat gain).

By the same token, you can gain excess body fat by overeating "clean foods."

Barring specific food allergies, health conditions, or an irrational fear of certain food additives (like corn syrup), there is no credible basis for the notion that you can’t eat "junk foods/processed foods" in moderation while improving your body composition and feeling your best health-wise.

Considerations on a Dirty Bulking Diet

As mentioned above, micronutrients (e.g. vitamins and minerals) are essential nutrients despite being devoid of energy (calories). While you can eat Pop-Tarts and drink soda purely to increase calorie intake, those foods/liquids are poor sources of vitamins and minerals.

Furthermore, not all carbs, proteins, and fats are created equal. For example, many processed vegetable oils abundant in packaged foods like chips, salad dressings, and dips — contain a large proportion of omega-6 fatty acids with pro-inflammatory effects in higher doses [1]. Consequently, getting most of your fat intake from these food sources skews the ratio of omega-3 to omega-6 essential fatty acids in the body, creating an unfavorable inflammatory response [2]. Eating plenty of "healthy fats" is crucial for everyone, no matter what diet they follow.

Similarly, not all protein sources have the same effect on muscle protein synthesis [3]. Where your protein comes from matters, especially if muscle gain is your priority.

The above examples illustrate the point that food is not just a source of calories and macros. Even when you follow a dirty bulking diet, food tracking is important to ensure you're getting a proper balance of micronutrients, as well as essential fatty acids ("healthy fats"), dietary fiber, and complete protein. Dirty bulking is not an excuse to consume as much "junk food" as possible.

Clean Bulking: Why Strict Diets Can Hinder Muscle Growth

When you view foods as being either "healthy" or "unhealthy," it's not uncommon to develop highly-restrictive eating behaviors that are paradoxically unhealthy in the grand scheme of things. Sure enough, rigid dieting strategies are a major risk factor for developing an eating disorder [4].

Not to mention, when you deprive yourself of food you genuinely enjoy for so long, even while in a caloric surplus, you end up giving into temptation and binging on "junk food" (which results in a vicious cycle of losing weight and gaining it back). In fact, there are quite a few compelling studies that show that "flexible dieting" is superior to "clean eating" since people who are less restrictive about their food choices don't feel the urge to binge or "cheat" on their diet (which can surely lead to excessive fat gain while bulking) [5, 6].

Moreover, food is oftentimes a social relief. Humans have a strong emotional/psychological connection with food, so you should eat foods you like while making sure to reach your macronutrient and micronutrient needs; two things that are not mutually exclusive.  

Therefore, a healthy and sensible bulking diet isn't necessarily "dirty" or "clean," because it's a matter of finding a balance.

Cheat Meals: How (Not) to Gain Weight

Many people scoff at the notion that having just one cheat day per week will lead to fat gain, but it absolutely can. Consider the example of a 170-pound individual with an estimated daily energy expenditure of 2,250 calories; this person sticks to a clean-bulking diet, eating 2,800 calories per day from Monday to Saturday, and then has a cheat day on Sunday with 7,000 calories.

Will they gain exclusively muscle mass or fat? Let's do the math and see:

• 6 days x 550 daily calorie surplus = +3,300 calories (~1 lb worth of calories)

• 1 cheat day x 4,750 calorie surplus = +4,750 calories (~1.25 lb worth of calories)

• 3,300 + 4,750 calorie surplus = 8,050 calories above weekly energy expenditure = upwards of 2-3 lbs of weight gain in a single week, which will undoubtedly be a good amount of fat gain at such a rate

So, yes, overindulging—even once a week—will surely contribute to excess fat gain. While it's normal/expected to gain some fat on a bulking diet, whether a clean or dirty bulk, the priority is improving body composition by gaining muscle mass and controlling fat gain.

There's good news, though: You can eat some "junk" foods while limiting fat gain and promoting lean muscle growth. The key is moderation and portion control, both of which are ironically the antithesis of cheat meals and cheat days. Once you acknowledge that there are no "off-limits" or "unhealthy" foods, you soon realize that you don't need to be so restrictive about what you eat, and you don't need to pick between dirty bulking and clean bulking diets.

Bringing Excellence Back to Bulking

Here's an example of a traditional "clean bulking" diet (without food portions listed, since they're relative to the individual):

• Meal 1—Egg whites and cooked oats

• Meal 2—Grilled chicken breast, rice, and broccoli 

• Meal 3—Same as meal 2

• Meal 4—Mass Gainer Shake

• Meal 5—Same as meal 2

• Meal 6—Casein Protein Shake

The first things that come to mind after looking at that diet should be monotony and restriction. It really shouldn't need much elaboration as to why "clean bulking" meal plans lead most people to crave cheat meals, especially if they're struggling to maintain a caloric surplus on nutrient-dense foods alone.

Since building muscle mass requires calorie intake to be greater than energy expended, it can be beneficial to occasionally indulge in calorie-dense foods, like pizza, burgers, pastries, etc. (This is mainly true for "hardgainers" during a clean bulk, though they may fare even better by dirty bulking.)

Hence, it's no surprise that people feel the desire to have a gratuitous cheat day or cheat meal every week when their bulking diet is exceedingly restrictive.

So, how do we fix this issue? Let's reconstruct the above clean bulking diet by incorporating some "dirty bulking" elements that make it not only more enjoyable but also healthier overall:

• Breakfast—Egg omelet and a bowl of oatmeal mixed with sliced strawberries and Greek yogurt

• Lunch—Roasted turkey breast on top of whole-wheat spaghetti with tomato sauce and mushrooms

• Post-Workout—Protein smoothie made with grass-fed whey protein, banana slices, and almond butter

• Dinner—Tacos made with lean ground beef, a side of black beans and rice, and roasted Brussels sprouts

• Dessert—Small bowl of ice cream with Oreos crumbled on top and a protein bar on the side

Notice how much more variety the sample diet above has compared to the previous example of a clean bulk. Also, note the inclusion of a modest treat at the end of the day helps avoid the desire for cheat meals. Eating a small amount of processed foods on a bulking diet won't lead to unwanted fat gain; if anything, it'll help increase calorie intake and stimulate muscle growth.

Dirty Bulk vs. Clean Bulk for Lean Muscle Growth: Key Takeaways

The best diet is one you can stick to while reaching your personal goals. The dichotomy of "clean and dirty bulking" lends itself to unhealthy eating behaviors on both ends due to their rigidity. It's far more sustainable to combine elements from both ends of the spectrum so you can stay in a caloric surplus without compromising your body composition and longevity.

However, for individuals with exceptionally fast metabolisms (i.e. hardgainers), clean bulking can be counterintuitive and may require periodic cheat meals to consume enough calories for muscle growth. As such, a dirty bulking diet may be the more prudent approach for these people to achieve a caloric surplus. Regardless, eating wholesome, nutrient-dense foods should still be a priority.

Conversely, those who tend to gain body fat more easily in a caloric surplus should probably avoid outright dirty bulking. Fortunately, there are plenty of ways to make a clean bulking diet satisfying; a little creativity in the kitchen goes a long way, and odds are you won't feel like you're "missing out" on anything by avoiding junk/processed foods.