In order to build muscle from a daily intake of 100 grams of protein you would need to weigh between 58.82kg (129.4lbs) and 83.33kg (183.33lbs). According to various sports science nutritionists, and as published by the American College of Sports Medicine (ACSM), a person should eat between 1.2 and 1.7g of protein per kilogram of body weight if they wish to increase lean muscle mass.
How Much Protein Do You Need to Build Muscle?
Protein is the most vital macronutrient when it comes to building muscle.
It’s full of amino acids and helps to repair muscle tissue that is typically damaged or broken down from our workouts.
However, it’s difficult to pinpoint exactly how much protein you need to build muscle.
Basically, you will find advice and calculations that vary dramatically depending on the source of the information.
Most government health agencies state that you should consume between 50-60g of protein a day.
However, a set amount of protein for every single person is pretty much useless.
This doesn’t take into consideration that people are different.
Not every person will be the same height or weight, and have the same activity levels, metabolic rates, etc.
Then there is the age-old bodybuilding adage which claims that you should consume 1 gram of protein per 1 pound of bodyweight.
So, this in effect is 2.2 grams of protein per kilogram of body weight.
With that being said, there are those who will state that too much protein can actually hinder muscle growth and cause weight gain.
For me, the perfect ratio of protein lies somewhere in the 1.2-1.7g per kilogram of body weight.
Once again, this will vary from person to person, mainly depending on how often you train and your metabolic rate.
As an example, most elite athletes will limit their protein intake to around 2 grams per kilogram of body weight.
So, unless you are an elite athlete, a slightly lower protein intake will suffice.
What Happens if You Don’t Get Enough Protein?
We’re aware that protein helps muscle tissue to repair and provides essential amino acids.
Amino Acids help with the synthesis of body proteins, hormones, and neurotransmitters.
So, they play a critical role in helping the body function.
However, if you’re not getting enough protein in your diet this can lead to various issues.
If you’re specifically training to build lean muscle mass, a lack of protein will work against you.
Firstly, you’re likely to feel weak and fatigued.
Plus, over time you can expect to lose muscle mass.
This of course will lead to less strength and will also slow your metabolism right down.
This is actually why protein is extremely important for weight loss.
Not only does protein help you feel fuller, thus reducing your appetite, it can also stimulate your metabolism.
So, if you’re not getting enough protein, you’ll not only lose muscle and strength, you’re also likely to see an increase in body fat.
If you get into the realms of severe protein deficiency then you could be looking at fatty liver, anemia, skin degeneration, etc.
Basically, not only is protein great for increasing lean muscle mass, it’s essential in maintaining your overall health.
What Happens if You Eat Too Much Protein?
It doesn’t matter what the macronutrient is, whether it’s protein, carbs, or fats – if you eat too much then the excess quantities will typically be stored as fat.
When it comes to building muscle, many people tend to have the view that more protein is better.
However, let’s not forget that too much of a good thing can also be bad.
So, by eating too much protein on a regular basis you will generally put on weight.
Additionally, the excess of amino acids cannot be stored or used by the body, and so they are excreted from the body.
This is often why when you have had a surplus amount of protein in one sitting you really need to poop.
Now imagine having too much protein with every single meal, and every single day.
Basically, you’ll be causing issues with the digestive system.
This also explains when you do have too much protein you typically feel heavy and bloated.
It’s also important to realise that too much protein can also cause certain health issues.
An excess of protein, whether in one sitting or evenly spread out over the day, can place a great deal of stress on the kidneys.
This can lead to immediate dehydration, but let’s not forget you’ll be feeling bloated, while also wanting to drink as many fluids as possible.
Not a good mix.
Plus, the continual stress and strain on the kidneys from too much protein can lead to more serious, long-term, health issues.
The vast majority of research into protein consumption indicates that consuming more than 2g of protein per kg of body weight over a long period can cause health issues.
Can You Eat Too Much Protein?
Is 40% Protein Too Much?
I’ve mainly spoken of protein consumption in terms of your body weight.
And while this is one of the easiest ways to gauge how much protein you should consume, there are other considerations.
Another way to look at it would be your overall macronutrient split.
A widely accepted macro split in terms of living a healthy lifestyle will typically be 45-65% carbs, 20-35% fats, and 10-35% protein.
So, your macro split in relation to your daily calorie intake should fall somewhere in between these guidelines.
However, your macro split can also differ slightly based on your goals.
If you’re trying to lose weight you will most commonly cut your carbs slightly, while increasing your intake of protein and healthy fats.
If your aim is to build lean muscle then your protein consumption could be the highest percentage of macros, while your carbs and fats intake will be fairly similar to each other.
For example, 40% protein, 30% carbs, 30% fats.
40% protein is fine if you’re looking to build lean muscle, but this shouldn’t be a long-term solution.
For many people consuming 40% of their daily calories from protein will mean that they are well in excess of 2g of protein per kg of body weight.
A 40% Protein Example
Let’s take a 70kg male who works out regularly, and requires approximately 2,500 calories a day to maintain his weight.
However, he wishes to bulk up, and therefore needs to consume 3,000 calories a day.
This would mean that he would need to eat 1,200 calories in protein to hit the 40% mark.
This equates to 300g in protein (protein and carbs have 4 calories per gram, whereas fat has 9 calories per gram).
So, in effect, he would need to consume just over 4g of protein per kg of body weight in order to satisfy a 40% protein split.
Now, while this may help him to bulk up in the short-term, much of the additional weight gain is likely to be fat as opposed to muscle.
Plus, he’s also likely to feel heavy, bloated, potentially dehydrated, and he’ll be pooping with extreme regularity.
If he continues in the same vein for a prolonged period he could be looking at potential health problems.
So, while I see nothing wrong with consuming 40% of your macros from protein, just be wary of how much protein you’re actually eating in relation to your body weight.
100 grams of protein is enough to build muscle, but this will depend on your weight. According to various expert guidelines you would need to weigh between 58.82-83.33kg in order to add lean muscle from 100 grams of protein. This would place you in the “sweet spot” of 1.2-1.7g of protein per kilogram of body weight.
Hi, I’m Partha, the founder of My Bodyweight Exercises. I’m someone who’s been passionate about exercise and nutrition for more years than I care to remember. I’ve studied, researched, and honed my skills for a number of decades now. So, I’ve created this website to hopefully share my knowledge with you. Whether your goal is to lose weight, burn fat, get fitter, or build muscle and strength, I’ve got you covered.