‘Dirty’ Bulking – Don’t Do It!

I am sure most of us are familiar with this term. A dirty bulk consists of eating the majority of your calories from “dirty” sources such as; burgers, pizzas, chips and fast food. Many people swear by its principles and have seen great gains; others have been ruined by it. In this article my goal is to educate you on why you should avoid a dirty bulk at all costs.

Bodybuilders of the past (there are some that still diet this way) would regularly transition between an off-season mass building periods to a super strict pre-contest fat loss diet plan. During the off-season period the primary goal is to pack on as much mass as possible with little to no concern over fat gain. During this period the only thing that matters is that the number on the weight scale continually climbs – if it stalls eat more! This is usually achieved by eating ridiculous amounts of food coming from predominantly “dirty” calories (fast food and junk food) hence the name dirty bulking. With this kind of bulking it is common to see weight gain of over 30kg in one offseason and muscle gain of a measly 2-5kg. Once reaching a target weight, its time to turn things around and strip off all that fat and go into your cutting phase and show off what you have under that belly.

Now instead of “off season” and “contest season” for bodybuilders, us regular folk have “winter” and “summer”. Winter is usually the time a dirty bulk occurs (Don’t lie we have all done it!) then before summer hits we start our cutting phase. Now with dirty bulking, as much as I hate to admit it, can be fairly effective with certain people in gaining mass quickly. More specifically, male teenagers can usually handle a dirty bulk quite well. This is due to increased insulin sensitivity (if they are not overweight) and a hormonal environment that is primed for growth. The problem arises however when this cycle is repeated over and over again. This constant weight fluctuation can ruin your health and cause long term damaging effects to your body. Bulking in this fashion should ideally be avoided at all costs.

Just don’t do it! – Why should we avoid dirty bulking?

The first and foremost reason is that you get fat! Adipose tissue (body fat) just like muscles cells grow in two ways; hyperplasia (increase in number of cells) and hypertrophy (increase in cell size). Your body can only utilize a certain amount of calories. Anything over this amount in excess quantities will be stored as fat. Continual overconsumption of calories will lead to continual fat storage. Once the existing fat storage units are full your body produces more fat cells to store fat. These newly produced fat cells are here to stay (unless surgically removed). So in short the more fat cells you have the easier it is to store fat and the harder it is to lose fat. Just like training your muscles to get bigger, by indiscriminately smashing calories you’re directly training your fat cells to get bigger. Who the hell does that?!

Allowing yourself to excessively get fat also has the possibility of increasing the amount of aromatase enzymes your body produces. We all know that testosterone plays a huge role in building muscle. Aromatase enzymes convert testosterone into the female hormone oestrogen…need I say more?

Lean mean Insulin machine!

In my personal opinion, the one key benefit to a clean bulk is a higher chance of continued insulin sensitivity. Ever wonder why lean people seem to have the most impressive gains? Leaner people can utilize the nutrients from their diet better.

Insulin is the mother of all anabolic hormones. Its job is to instruct the cells to open up and shuttle vital nutrients such as amino acids in for protein synthesis. Being continually insulin sensitive increases the effectiveness of nutrient delivery to the muscles. A clean diet emphasizing complex carbohydrates has the ability to maintain stable blood sugar and insulin levels. A dirty bulk on the other hand, consisting of processed carbohydrates such as pizza dough and burger buns can cause regular insulin spikes due to the large increase in blood sugar levels. These continued spikes would easily de-sensitise your cells ability to respond to insulin, thus decreasing the effectiveness of nutrient delivery to your muscles and reducing the chances of protein synthesis occurring. Perhaps the issue is more that dirty food tends to push you over your caloric limit more easily than clean bulking?

Insulin may be the most anabolic hormone in your body but it also acts as a lipolytic (fat storing) hormone. It does this by shuttling fatty acids and glucose into fat cells. An individual who is insulin resistant will be over-producing insulin, which in turn reduces lipolysis (fat burning) by increasing lipogenesis (fat storing).

Caloric density vs Caloric quality

To gain muscle you need to be consuming more calories than you use. This is where a dirty bulk trumps a clean bulk. It is extremely easy to eat in a caloric surplus by eating junk food (very high in calories). With three quick meals a day of burgers and pizzas you can easily surpass your daily caloric and macronutrient needs. This is also why it is so easy to gain fat on a dirty bulk; you are continually surpassing the upper caloric limits that your body can utilize. Eating enough calories through a clean diet requires planning, meticulous preparation and the will to eat, which can be time consuming and annoying.

Not all calories are created equal. The quality of calories from a dirty bulk (or lack there of) can hinder your muscular gains. Good quality calories are dense in micronutrients. Clean eating emphasizes consumption of good quality calories through non-processed foods, such as lean meats, healthy fats, complex carbs and a range of vegetables. These food groups will ensure adequate micronutrient uptake, which is needed for hypertrophy. A diet based on processed fast foods lacks many vital nutrients such as zinc. Zinc plays a role in hundreds of enzyme processes within the body, the most important being; aiding in building DNA, protein, insulin and testosterone production. A lack in zinc can affect any one of these processes, which can hinder your hypertrophy goals. A simple take home message is just to eat more good quality food!

I command you to GROW!

Muscle growth does not happen linearly and cannot be forced by over consuming calories (as much as everyone wishes this was the case!). This is where dirty bulking is practically useless. A dirty bulking diet will not produce more muscle growth over a clean diet emphasizing the consumption of equal amounts of macronutrients and calories

Less to lose more to gain

Clean eating for hypertrophy maximizes muscular gains by ensuring effective nutrient uptake into the muscles and decreases fat gain through stable insulin levels and a controlled caloric surplus. This means; come cutting time the process is so much easier, simply causing you got less fat to lose.

Kicking the habit

In my personal opinion, there is also the psychological aspect of switching from “dirty” foods to “clean” foods. When you’ve been accustomed to binging on burgers, pizzas and chips at every meal, it is so much harder to curb your cravings when you return to lean cuts of meat and fresh vegetables. These cravings can easily sabotage your cutting phase and bring you back to square one. By sticking to a clean diet with an occasional cheat meal here and there it allows you to control these urges more effectively and keep you on the right track.


A dirty bulk may produce quick short-term results by filling out that t-shirt and bending the scales, but it may be counterproductive in the long run when it comes to building quality muscle and obtaining a good physique. A dirty bulk will make your physique look big in a shirt but fat without one, a clean bulk, however, may take a tad longer but your physique will look good, period.

Building muscle cannot be forced; it takes time, patience and consistency. Why bother with a diet that makes the scales shoot up in a few weeks, but has the possibility to cause short and long term problems, when you can build good quality muscle eating foods that benefit your mind body and soul.
Article by Alex Hunter, UP Causeway Bay