Overview, Guide, and Best Foods

While weight loss is generally a more common goal than weight gain, many gym-goers are interested in putting on weight to increase their muscle size and strength.

There are several ways to accomplish this, though some result in excessive fat gain, which certain athletes and fitness enthusiasts may find undesirable.

Conversely, clean bulking is said to be a sustainable, healthy strategy.

This article explains how to clean bulk, reviewing its effectiveness, downsides, and foods to eat and avoid.

In general, bulking is a sustained calorie surplus — in which you eat more calories than you burn — which leads to weight gain in the form of muscle or fat. This eating strategy is combined with high intensity resistance training to boost muscle and strength gains.

When following a clean bulk, also called a lean bulk, you tightly regulate your calorie surplus in an effort to prevent excessive fat gain.

The diet is mainly comprised of minimally processed whole foods. High calorie junk foods are limited to promote a leaner body composition.

Clean bulking is often utilized by athletes who desire to stay relatively lean in the off-season, such as mixed martial arts (MMA) fighters, boxers, gymnasts, strength athletes, and physique athletes.

That said, this approach isn’t for everyone, as its associated weight gain tends to occur slower than it does with other bulking methods.

How does it compare with dirty bulking?

In opposition to clean bulking’s measured, slow approach is the dirty bulk.

Under this strategy, no foods are off-limits. Rather, you’re meant to pack on as much weight as possible regardless of any associated fat gain.

While a dirty bulk may be extremely effective for gaining muscle and strength quickly, its side effects include excess fat gain, feelings of sluggishness, and high cholesterol and blood sugar levels.


Clean bulking promotes a controlled calorie surplus for building muscle while minimizing fat gain. Unlike with dirty bulking, you keep a tight leash on the types and amount of foods you eat.

The first step to starting a clean bulk is to establish your maintenance calories — the number of calories you need to maintain your weight. Several online calculators can help you estimate this number.

You then tack on a 10–20% calorie surplus. For example, an average-sized, 175-pound (79-kg) man would add approximately 250–500 calories, while an average-sized, 135-pound (61-kg) woman would add about 200–400 calories (1).

From there, ensure a daily protein intake of 0.7–1 gram per pound of body weight (1.6–2.2 grams per kg) to support muscle gain. The rest of your daily calories are made up of carbs and fats, depending on your preference (1).

It may be helpful to track your intake using one of several smartphone apps.

Weigh yourself regularly to track your progress, shooting for a weight gain of 0.25–0.5% of your body weight per week (1).

For the same 175-pound (79-kg) man and 135-pound (61-kg) woman, this equals 0.4–0.8 pounds (0.2–0.4 kg) and 0.3–0.6 pounds (0.14–0.28 kg) of weight gain per week, respectively.

If the number on the scale isn’t moving, slowly bump up your weekly calorie intake by 100–200 calories.


Clean bulking requires calculating your maintenance calories, adding a conservative calorie surplus, and tracking your progress with regular weigh-ins.

Unlike dirty bulking, clean bulking focuses mainly on whole, unprocessed foods — though it allows small amounts of high calorie, processed items.

While all foods can be enjoyed in moderation, certain foods may make it more difficult to maintain a controlled calorie surplus. It may be best to limit or avoid some of these items.

Foods to eat

  • Lean proteins: chicken, fish, turkey, beef, pork, Greek yogurt, cottage cheese, reduced fat cheese, protein powders, tofu and tempeh, and eggs and egg whites
  • Healthy fats: olive oil, avocado, nuts, nut butters, fatty fish, and seeds like chia, hemp, and flax seeds
  • Legumes: all beans, including chickpeas and kidney, navy, black, and great northern beans
  • High quality carbs: oats, quinoa, whole grain pasta, white and sweet potatoes, and white and brown rice
  • Fruit: apples, oranges, bananas, pineapple, grapefruit, and all types of berries
  • Non-starchy vegetables: peppers, asparagus, green beans, mushrooms, onions, tomatoes, zucchini, carrots, and celery
  • Cruciferous veggies: broccoli, cauliflower, Brussels sprouts, and cabbage
  • Dark leafy greens: spinach, Swiss chard, collard greens, and kale
  • Beverages: water, seltzer, diet soda, tea, coffee, and kombucha

Foods to limit or avoid

  • Highly processed foods: fried foods, canned soups and stews, sugary cereals, chips, fast food, and full fat ice cream, plus packaged pastries, cakes, and cookies, and processed meats like bacon, sausage, ham, salami, and pâté
  • Proteins: fatty cuts of beef or pork, as well as processed pork or beef sausage
  • Saturated fats: margarine, butter, and certain oils
  • Beverages: soft drinks, sweetened coffee, sweet tea, lemonade, and other sugary drinks


A clean bulk focuses on whole, unprocessed foods while generally curtailing processed foods high in fat, sugar, and calories.

Clean bulking may provide several advantages over dirty bulking.

May limit excess fat gain

Since clean bulking provides a much more calorie-controlled approach than other bulking methods, it tends to prevent excess fat gain.

It’s well established that when setting out to gain muscle, you should maintain a calorie surplus (2, 3).

Data suggests that a conservative surplus of 350–500 calories per day is usually effective to promote muscle gains while minimizing fat storage. This numbe
r coincides with the recommended calorie surplus for a clean bulk, which tends to be on the conservative side (3).

Conversely, dirty bulking uses a higher surplus — normally exceeding 500 calories per day — to target weight and muscle gain regardless of excess fat gain.

May prevent negative health effects

The careful, tapered approach of clean bulking may lower your risk of negative effects associated with excessive calorie intake.

Keeping a significant calorie surplus puts you at risk of higher levels of cholesterol and blood sugar, which may increase your risk of chronic disease (4, 5, 6).

Yet, clean bulking uses a tightly regulated calorie surplus and emphasizes whole, unprocessed foods.

Keep in mind that the effects of maintaining a calorie surplus are highly individual. Thus, it’s important to consider any underlying health issues before starting a bulk.

Excellent nutrition content

Since a clean bulk is comprised predominantly of whole foods, its nutrient content tends to be superior to that of a dirty bulk. Specifically, it’s higher in vitamins, minerals, phytonutrients, and fiber.

Phytonutrients are plant compounds associated with anti-inflammatory effects (7).

High fiber diets are linked to good digestive health and a reduced risk of various ailments, including type 2 diabetes, heart disease, and cancer (8, 9).

While the foods eaten on a dirty bulk aren’t necessarily void of quality nutrients, the more processed nature of the diet lowers the overall nutritional value.


The foods eaten on a clean bulk tend to be of higher nutritional value than those on a dirty bulk. What’s more, clean bulking may limit excess fat gain and lower your risk of negative health outcomes, compared with dirty bulking.

Clean bulking may provide several advantages over dirty bulking, but you should be aware of a handful of downsides.

Your progress may stall

Due to clean bulking’s tightly controlled calorie surplus, your progress may be slow and could even stagnate.

Building muscle is an energy-intensive process. When utilizing a conservative calorie surplus, such as in clean bulking, it’s easy to underestimate the number of calories needed to build muscle (10).

If you consume too few calories, you may cease to gain muscle.

To prevent a plateau, it’s best to start with a conservative surplus of 350–500 calories and track your progress by regularly weighing in. From there, you can slowly add calories until you reach your desired rate of weight gain (3).

May lack flexibility

Clean bulking promotes a fairly rigid eating pattern.

You’re meant to adhere to a limited number of foods to prevent excess fat gain and maintain good health. For instance, you’re largely discouraged from eating processed items high in fat or sugar, such as pizza, cakes, sausage, bacon, and regular soda.

These restrictions may be difficult to maintain long term, as well as during social occasions like parties.

Nonetheless, it’s up to you how closely you follow the clean bulking protocol.


Clean bulking can be fairly rigid in its permitted foods and calorie allowances, and you may run the risk of limited muscle gain by underestimating your calorie surplus. Keep these drawbacks in mind before starting.

While clean bulking is rather restrictive and dirty bulking may lead to excess fat gain, you can try to strike a balance between the two.

In general, bulking can be seen as a spectrum, with “clean” and strict on one side to “dirty” and lax on the other.

If you wish to find a happy medium, dedicate about 90% of your calorie intake to whole, unprocessed foods and the other 10% to discretionary calories from high fat or high sugar foods.

This approach may provide the best of both worlds, as it promotes lean muscle gain, limited fat gain, and more dietary flexibility.


If clean bulking’s limitations are a hindrance, you can give yourself more dietary flexibility while still eating mostly whole, unprocessed foods.

Clean bulking is an eating pattern that provides a controlled calorie surplus to build muscle and strength while preventing excess fat gains. This method is often utilized by athletes who can’t afford to gain too much fat when attempting to grow muscle.

Although clean bulking is healthier than dirty bulking in several ways, bear in mind that it’s less flexible and runs a higher risk of stalled muscle gain.

Remember to check with your healthcare provider before starting any diet, especially if you have any underlying health conditions.