This article will take you 12 minutes to read. Feel free to leave your questions in the comment section, they will be answered!
If you’re spending time on this website, you know that we try hard to give you good information about natural bodybuilding and that whenever you have a doubt about dieting and nutrition, you can read this over and over again.
We are going to cover the principles of adding-weight/losing weight in the first part, as well as bulking and cutting in the second part. If you ever wondered whether you should do cardio to lose weight, you will have an answer in the third part.
This ultimate natural bodybuilding guide to dieting and nutrition will explain you how you can master a good diet to reach your body goals. It doesn’t need to be complicated – and you’ll have a working understanding of nutrition by the end of this article!
Table of Contents
1- How do you lose or gain weight?
These are simple maths!
Here’s the single most important lesson you need to learn:
Weight changes in response to calorie balance. Eat more than you use? Gain either muscle or fat. Eat less than you use? Lose either muscle or fat.
It’s why people track calories when they’re on a diet or performing intense exercise: calories tell you how much energy you’re taking in. That energy is used to fuel the body and repair it after intense activity or exercise.
The balance matters because your calories in includes food, while your calories out includes your resting metabolic rate, your activity levels through the day, and then any structured exercise or sport you do on top of those.
Sometimes calories can seem scary – but it’s not all about cutting back. It’s about eating the right amount for you: calories are only good and bad depending on your goals and your own needs!
The idea is that you should eat the number of calories you need to make your body do the things you want (i.e. your goals). It’s the relative calorie intake that matters – so don’t treat calories like the problem.

Often, people will tell you they’re doing high reps with light weights to cut down and to ‘burn more calories’ and ‘shred down’ or doing cardio to lose weight. But they don’t lose weight – because their balance is incorrect.
Activity levels alone won’t usually help people lose weight. Diet does most of the work and being aware of calorie intake is a really useful tool to put you in charge of your diet. It doesn’t have to be restrictive – it should be empowering!
It’s easier to reduce your intake by 200 calories than it is to burn 200 calories!
Focus on YOUR Maintenance Needs
Every day your body needs to consume a certain number of calories for its weight and activity level. If you go past that amount, it then isn’t necessary for function, so you start storing fat.
On the other hand, if you are not reaching that maintenance level, you are telling your body that you are not consuming enough energy. Therefore, your body will start burning stored fat and even muscle mass to produce the energy needed.
This is how the body’s weight change happens and it’s important to notice that it all starts with maintenance levels. The amount you use on a daily basis is called your TDEE (total daily energy expenditure) and you can use calculators to get a general estimate.
However, these are estimates and you’ll only know if you’re working with the right number based on what happens to your body when you change your diet. You’ll know if you’re using the right amount based on what happens to your physique and on the scales.

Weight-loss in a simplistic example
Let’s illustrate this example so it makes a little more sense.
John is an 80kg male, working a 9-5 with a lot of walking. He needs 2800 calories to maintain his bodyweight based on his everyday activity levels. John is too busy with work to eat properly, and only eats 2500 calories a day. His body is in a calorie deficit of 300 calories a day.
As John isn’t consuming that much energy anymore, his body will start taking it from the fat he is holding and his muscles. John’s bodyweight drops towards a point where his TDEE is what he’s eating. Simply put, your body will meet whatever intake you’re using to fuel it.
Your body will find a balance as you lose weight, or (on the other hand) gain weight. This drives changes to the fat and muscle of people on diets, either for muscle gain (balancing upwards by eating more) or fat loss (as mentioned above).
Summarizing gaining and losing weight
o Calorie surplus (eating more than TDEE) = gaining weight
o Calorie deficit (eating less than TDEE) = losing weight
If your goal simply is to lose weight whether it is fat or muscle, you can go that route.
One of the priorities for gaining or losing weight is what you’re gaining or losing. You want to gain muscle and lose fat, but not the other way around. When you gain weight, you want it to be lean, while losing weight should be about preserving muscle mass.
Muscle isn’t just for bodybuilders: it supports joints, maintains metabolic health, and keeps your body prepared for anything. This is why we can get more complicated about what you’re eating and how you’re training – they influence what you gain and what you lose.
If we talk about gym and bulking, we are talking about having a calorie surplus and when we refer to cutting, we are going the calorie deficit route. Now that we have talked about how losing weight and adding weight works, we can go deeper into macronutrients and why they’re important. These are the nutrients that decide what the calorie content of foods are – and what they do in your body…
Macronutrients: Why They Matter
Let’s start with the very basic principles of nutrition for bodybuilding.
You can get a simple overview with 3 major points:
- Calories
- Macronutrients
- Micronutrients
With a good understanding of these basics, you can use your diet for just about any body goal, weight loss, muscle gain, or sport performance goal you want. Nutrition isn’t complicated, to start with – and these points will help you take control of your body.

This starts with the macronutrients – protein, fats, and carbohydrates. These are the macronutrients because your body needs lots of them. They are the main sources of energy and resources for your body to perform its self-repair functions and fuel key processes.
On the other hand, micronutrients are vitamins and minerals. They’re taken in smaller quantities, but are just as important for supporting those crucial processes in the body.
These are the two categories of nutrients you’ll need to remember today. When we are talking about cutting and bulking – changing weight and the relationship between nutrition and physique – they’re going to be really important.
This is the energy you get from macros:
o Carbs: 4 calories per 1 g
o Protein: 4 calories per 1 g
o Fat: 9 calories per 1 g
The Proteins

Proteins are very important = to help your body recover from stress and help muscle tissues to recover and grow after a workout. People with little experience in the gym will almost accuse you of being on steroids
for consuming whey protein! Everyone talks about proteins when it comes to the world of bodybuilding.
It’s important to remember that protein comes from food – and additional protein supplements might be popular, but they’re not essential. You need dietary protein and the usual sources are lean meats, seafood, and eggs.
Vegetarians and vegans will get their protein from beans and seeds, as well as foods rich in seitan or other deliberate protein-rich foods.
The Fats
Dietary fats are often neglected because they’re not as common in the diet. A lot of people also hear the name and worry but, no, dietary fats do not make you fat. They’re high in energy but they only make you fat if you over-eat and under-exercise which would set you at a high calorie surplus.

Fats are actually essential and a great source of energy. They absorb minerals and vitamins and are needed to build cell membranes, to keep your organs safe. Fats should be included at a lower rate than protein or carbs due to their higher calorie count. Because of this, they should also be eaten for quality – the best sources of fats are fish and seafood, cultured dairy (like yoghurt), and nuts/seeds.
Carbohydrates

Carbs are your short-term energy source, including both starch and sugar. They’re the main form of energy in our diets today and the main form of energy for building muscle. Carbs fuel your brain, muscles, and liver, primarily. Then, from there, they are transported out to organs to maintain energy levels and help them do their job – like the kidneys.
For anyone wanting to either bulk, cut, lose weight, or gain weight – it is essential to understand about macronutrients even if you have any of these goals in mind.
2- Bulking and Cutting: Weight Change Goals
For bodybuilding, weight gain and loss are a little more deliberate than for normal fitness. They’re usually broken up into two phases: bulking or massing and then cutting.
Bulking is when we aim at building more muscle mass and cutting is about preserving that mass while cutting down bodyfat. These are the two major factors for bodybuilders – bigger and leaner!
The bulking phase
Bulking is all about providing your body with all the fuel it needs to get bigger and stronger. When you train hard, you need to give your body and muscles plenty of calories and protein to recover and grow. All the while, you will need to maintain a structured routine, that helps you improve in the long run. The balance of training effort to nutrition is the basic “loop” that makes physical change work.

Theoretically, your goal is to grow muscles while adding as little fat as you can. Then it depends on which route you want to take, as sometimes people will need less of a “clean bulk” to feel full of energy, do great sessions, and get quicker results.
This keeps them more motivated seeing performances go up. However, others will be more patient and accept not growing as quickly, maintaining a smaller calorie surplus to avoid gaining too much fat. Ultimately, if your weight goes up too quickly, don’t fool yourself, it probably is fat.
The attitude you take determines what kind of bulk you’re looking for:
Heavy bulking: eat a lot (moderate to a large calorie surplus 500kcal), add maximum muscle mass, but get a bit chubbier (you can
always cut it down later)
Clean bulking: eat enough to gain weight slowly and avoid gaining too much fat –
you don’t need to cut as much and you’ll look better on the way (low calorie surplus, 100-150kcal)
It’s all down to personal preference and where you’re starting.
Clean bulking is very sustainable, and is great for consistently improving (slowly) in the gym!
It’s important to escape stagnation
The most important in my opinion is to escape stagnation. People sometimes stagnate for too long – they don’t pull the trigger on nutrition.
Just take the example of a lawnmower, some need a gentle pull to get started while others might require to pull the cord harder and repetitively to get started.
Some people see a difference with a small calorie surplus, others need more than that.
Increase your calorie intake slowly and if you can’t see any differences after a few weeks, you can go a bit harder on the calories.
Here are two articles which might are related to the importance of eating enough to build muscle:
o The hard-gainer guide
o 5 steps to get big fast and without steroids!
The cutting phase
Cutting is about keeping all these muscles you have been building during the bulking phase – but burning fat so you can show them off! You don’t want to mess up this phase if you want to see the results of your hard
work. The cut has a different approach than the bulk.
There’s no way around how you cut: it needs to be cleaner. You can’t rush the cut process because you’ll increase the amount of muscle mass being broken down for energy. Patience is key on a cut.
Reducing your calories as little as possible and adjusting upon what the scale says is the key to results. You can’t rush it, or you’ll have a worse end-result as your body eats up the muscle you spent so long building!

Trying to keep it as healthy as possible will also play in your favour.
Cutting and bulking are similar in the way that the food you consume should be helpful in reaching your body goals. Consequently, the healthier you eat, the better you will do in the end – whether it is a bulk or cut.
It is harder though to eat cleaner on a bulk than on a cut, because healthy foods (like
dark green veg) tend to be low calorie. However, these are your best friend while
cutting:
They’re low in calories
They’re rich in vitamins and minerals
They’re very filling and help you beat hunger
Use plenty of fiber-rich foods like vegetables and wholegrains on a cut, keeping you
feeling full while controlling your calorie intake.
So how do you keep all your muscles whilst only losing fat?
You’re probably going to lose some muscle while you cut.
However, the better you manage your diet and exercise, the more you can keep. You may also look bigger as you lose fat due to the changes in your proportions and the increased definition that it brings to muscles.
Good cut diets are rich in protein to support muscles, which prevents them being burned up for energy. Equally, regular heavy lifting will remind your body that you need muscle mass and improve its muscle-sparing signalling.

How do you limit muscle loss on a cut?
Give your body the right amount of energy with the right food. We need to use the proteins, carbs, and fat in the best possible way. Your diet should focus on protein first and foremost, and then carbs around training time to provide energy.
You can prioritise wholefood-based micronutrients (think fruit, veg, nuts, and seeds) and use smart supplementation (like a multivitamin and cod liver oil) to give your body an extra boost to achieve your goals and keeping you sane as well!

On a cut, more protein is better. We want to aim for a minimum of 1.5grams of protein per kilo of bodyweight, but more is going to be better for cutting to make sure muscles are properly fuelled and supported.
How much carbs do you need?
Once you’ve got your protein in, you need to eat 15-20% of your calories from high-quality dietary fats. I personally eat between 0.5 and 1gr of fats per kilo of bodyweight – I recommend around 20%.
Let’s imagine you need to consumme 2500kcal everyday and you are a man weighing 80kg.
You’re going for 0.5 gr of fat per kilo of bodyweight and 1.5 gr of protein per kilo of bodyweight.
It will result in 1.5x 80=120 gr of protein and 0.5×80=40 gr of fats which equals to 840 calories in total (480+360).
You then need 1660 kcal of carbs to reach your target, 840kcal (fat+protein) + 1660kcal (carbs) =2500kcal.
Calculate your proteins and fats first – then what’s left is for carbs.
Whatever is left you should focus on carbohydrates. Carbs are the source of energy for muscles and make up the energy stored in muscles – glycogen. When we exercise, glycogen is burned up but it’s also one of the main sources for repairing muscle.
If your muscles are energy-negative for too long they start breaking down. Proteins and carbs are the magic combo for keeping muscles big and strong and healthy. Prioritise these two nutrients and make sure most meals contains some.
Carbs are the balance
It is very important to understand that when cutting, carbs are the balance.
The fats and proteins are almost static, just adjust them to your new bodyweight when you start losing weight. Then you use your carbs as the balance, they’re the main factor you’re using to reduce the calorie intake when needed or upping it.
Cutting the carbs and going on a ketogenic diet is not something we’d recommend.
Carbs fuel your muscles and your performance. Natural bodybuilding works best when we maintain regular carb levels as often as possible, but a cut will involve bringing carb levels down – but we shouldn’t use low-carb diets. But what about the other side of the energy equation – what about your “calories out” section?
Lets talk about cardio and using more calories…
3- Should you do cardio when cutting?
Debunking the myth

We often hear people say that they need to start doing sports or running to lose fat. But once you know losing weight only comes down to a calorie deficit, it’s obvious that you don’t need cardio.
A lot of people who do cardio on a cut or to lose weight do not really know why they are doing it. They associate cardio with losing weight, but miss out on the diet and lifting aspect of changing their physique.
Cardio obviously uses up calories – but so does almost everything else. We can get the same calorie balance without it, and other exercise – like strength training – helps us lose weight while building or maintaining muscle.
So what’s cardio for?
When should you do cardio?
Case 1: Doing cardio at the end of your cut
You can usually easily lose weight only by modifying your diet and sustain a calorie deficit.
In extreme cases, like at the end of your cut and already calorie restricted – you might want to do some cardio to dig even deeper and push the calorie deficit without having to reduce the amount of food you’re eating and end up in starvation.
It’s better, in this situation, to be more active rather than continuing to cut calories. It’s also something that you’ll find helps you maintain consistent weight loss over time, since your calorie-demands stay relatively high.
Case 2: Doing cardio if it makes you feel good
If you want to cut down, but still eat a lot of calories, then you can implement some cardio to burn those extra calories you have enjoyed.
Just like lifting, running is a rewarding form of exercise (e.g.). It’s good to get better at things and a lot of natural bodybuilders use cardio to work on other things like fitness and cardio-respiratory health.
While cardio is optional, it can be a really nice experience to get into your routine – even 1-2 times a week. We don’t need cardio to change our physique, but it does offer enormous health benefits especially when combined with regular strength training.
You can also find a lot of joy in the progression, or in taking up a more athletic type of training for your cardio. Natural bodybuilding is great but feelings of strength and fitness don’t always overlap. Cardio is a chance to feel better as well as looking better!
Equally, if you’ve already put time into cardio and don’t want to stop in your journey to build muscle, a cut is the perfect time to shift your focus towards that and get the best of both worlds!
We hope you have learned a lot from this ultimate guide summarising the basics of nutrition and dieting in bodybuilding.
If you have any questions, please feel free to leave a comment!
Thank you, take care of yourself.