How to Bulk Properly: Build Muscle Fast Without Getting Fat

There is nothing in the world more frustrating than training hard in the gym, week after week, and not seeing any progress. If this sounds familiar, or you simply want to align your diet with your training, this guide is for you.

The term ‘bulking’ is a phrase in fitness that refers to eating in a calorie surplus with the goal of building muscle. But it’s not just about stuffing your face and hoping for the best. Smart bulking means gaining size without piling on unnecessary fat, and doing it in a way that actually supports your health, performance, and long-term goals.

There are two main reasons why people bulk:

Increase Muscle Mass: A calorie surplus fuels your body with the extra energy required to repair and build muscles after workouts.
Boost Strength and Performance: Bulking allows you to train harder and use progressive overload, leading to greater strength over time.

In this guide, we’ll break down what bulking is, how it works, how to do it properly, the most common mistakes to avoid, and how to build a plan that actually works for your body and lifestyle.

How Does Bulking Work? 🧠

At its core, bulking is about consuming more calories than your body burns in a day. This is called a calorie surplus, and it’s essential for muscle growth. When you pair that surplus with proper training, your body uses the extra fuel to repair and grow your muscles bigger and stronger than before.

Here’s the process in a nutshell:

Training breaks down muscle fibres: When you lift weights (and follow How to Train for Hypertrophy: The Smart Way to Build Muscle Fast), you create tiny tears in your muscle fibres. This is a good thing as it triggers the body to start building back bigger and stronger.
Your body uses fuel: Protein and calories from your diet provide the raw materials to recover from your training. Without enough of either of these things, muscle growth will be slow/non-existent.
Excess fuel is stored as fat: If your body doesn’t use all of the surplus calories for building muscle or meeting daily energy demands, the excess is stored as fat.

This brings us to the two schools of thought when it comes to bulking:

The clean bulk: Eating in a small, controlled surplus – just enough to build muscle, while minimising fat gain. Food choices are mostly whole, nutrient dense and unprocessed. This takes a lot of effort, planning, and discipline, but it is the healthiest way to bulk and is fairly easy to transition out of.
The dirty bulk: Eating in a large calorie surplus and not worrying too much about fat gain or food quality. Food choice is pretty much a free-for-all, as long as you hit your calories and protein. Burgers, pizzas and milkshakes are all on the menu and muscle gain will likely be faster, however you’ll also put on more fat and be generally unhealthier than on a clean bulk.

Most people bulking will lie on a spectrum between these two extremes. This guide will focus more towards clean bulking because the aim is to promote an overall healthy and optimised lifestyle.

The Key Principles of Bulking Effectively ➡️

As mentioned, a clean bulk is one of the most difficult things to pull off because there are many factors you need to balance. You need to eat enough, not too much, hit an optimal range of macro nutrients, hit healthy levels of micro nutrients, eat clean, whole foods while also aiming for high calories, and then you only have so much time in the day and so much money in the bank. It’s like everything has to be balanced on a tightrope. These key principles will simplify out your main priorities so you have clear aims and actionable steps to follow.

Calories: How big should your calorie surplus be?

To gain muscle, you need to eat above maintenance calories. Here’s how to set up your calorie intake:

Start With Maintenance Calories: Use a calorie calculator to determine how many calories you need you need to maintain your weight.
Create a Calorie Surplus:
- Aim for 10–20% more calories than your maintenance.
- Choose the higher end (20%) if you want faster muscle growth, accepting a little extra fat gain.
- Stick to the lower end (10%) if you want to minimise fat gain.
Example: A 25 y/o male weighing 75kg at 180cm would need around 2400 calories to maintain weight with a lightly active lifestyle. To bulk, he would consume an extra 10% (240) to 20% (480) of his maintenance calories. This would total at 2640-2880 calories.
Calories per pound: From a scientific standpoint, it should take 3500 calories to gain 1lbs of weight. You may not see this exact result on the scale due to multiple lifestyle factors, but it’s a good rule of thumb to remember when calculating your calories.

Macros: How much protein do you need to build muscle?

There are many ways to decide your macro split, and as long as you follow some ground rules, the rest is pretty easy. The amounts listed below are for a standard diet (not keto etc).

Protein

Aim for 0.8–1.2g per pound of body weight (1.75–2.65g per kg).
Good sources: Chicken, beef, fish, eggs, Greek yoghurt.
This is your main priority. Hit your protein goal every day.

Fats

Aim for 0.45–0.65g per pound of body weight (1–1.4g per kg).
Make sure you get your fats from good sources, not just saturated fats.
Good sources: Avocado, nuts, olive oil, fatty fish.

Carbohydrates

Use the remaining calories for carbs.
Remember: 1g of carbs = 4 calories.
This should work out at around 50-60% of total calories, which is good for fuelling workouts.
Remember, carbs are not the enemy and are a staple part of a successful bulk.
Good sources: Rice, oats, potatoes, fruits, pasta, whole grains.

Track Your Progress: How do you know if the bulk is on track?

Yes, you can always flex in the mirror every morning and convince yourself you’re looking bigger, but the most optimal way to track a bulk is to actually track it. This will allow you to adjust the bulk accordingly and ensure your results are consistent and surprise fat gain doesn’t creep up on you.

Aim to gain 0.5 – 1% of your bodyweight per month. If you do the maths in the above example, you’ll see that eating at a 10-20% surplus is pretty spot on to achieve this goal.
Weigh yourself a couple of times per week as a baseline goal. If you feel like you can weigh yourself more without it getting in the way of your life, you can, but the key is to focus on long term trends rather than day-to-day fluctuations. I’d recommend tracking your progress on excel and plotting your results over time with a trendline. This will require basic excel skills which are unfortunately outside the scope of this guide.
Adjust calories accordingly. The key is not to overreact, track consistently and make sensible decisions. If your weight has decreased for the third week on the bounce, it might be time to increase your calorie intake slightly. If your weight has skyrocketed and continues to do so 3-4 weeks into a bulk, you’re probably eating too much. Make sure you’re tracking accurately, sticking to plan, and accounting for any cardio activities before making small adjustments to your calorie goal.

FAQs 💡

Does it matter what you eat, or just that you hit your calories and macros?

This is really a personal choice as eating processed foods, clean foods, or a mixture of both will work from a muscle building perspective as long as your goals are hit. If you want to optimise for ease, taste and convenience, eat highly processed food. If you want to optimise for health, nutrition and skin, eat clean foods. Eating clean, whole foods with the odd tasty treat (ideally staying within calories and macros) will be a happy middle ground for most people.

When should I stop bulking?

You may have heard the term ‘every season is bulking season’, and while it’s great to see your lifts improve and to look huge in a t-shirt, you’re probably going to want to trim down at some point. Set a goal weight by a certain date and stick to it. What you do after that depends on your overall goals.

Full cut: a properly planned cut for a long period of time. The goal here is to get ‘shredded’ ie. Super lean.
‘Mini’ cut: a shorter cut aiming to lose some excess fat and ‘realise’ some gains before you bulk again.
Maintain: if you’re happy with how you look and don’t care too much for leanness (which is fine), stick to your maintenance calories.
Middle ground: as always, there is a middle ground. Decide what you want to look like and what you want your lifestyle to look like and stick to it.

Key Takeaways 🍗

Eat well, train hard. Bulking should be fun, but it’s even more fun when you finish a bulk and don’t look like a potato. Keep your goals in mind, stay consistent, and don’t neglect tracking. Do everything correctly and next summer could FINALLY be your summer.

Notes 📝

Notes

Does consuming more micronutrients significantly affect muscle growth?

What’s the difference between different types of fats – saturated, monounsaturated etc. Are any more important for bulking than others? Are saturated fats all bad?