Easy-To-Follow Nutrient Ratios: A One Minute Lesson

What you are about to discover is a sure-fire, effortless way to easily determine an appropriate nutrient ratio for your own personal goals.But before I get too far ahead of myself, make sure you understand how to estimate your caloric and protein needs. I’m going to 3,000 as the overall calorie requirements for any examples.

While there are several methods to determine your nutrient ratios, this will explain two popular methods referred to as the ISSA 1-2-3 Nutritional Rule-of-Thumb (International Sports Sciences Association). Once you know how many calories a day you need, you can determine the correct ratio.

Let’s examine the ISSA intake guideline of approximately 1 part fat, 2 parts protein and 3 parts carbohydrates. This is generally accepted as a safe way to burn fat for those who are weight training and exercising.

If you were to follow this rule, you would guarantee you you’d be following a diet that was low in fat, moderate in protein and high in carbohydrates.

This probably comes as no surprise but this rule-of-thumb makes it amazingly easy to prioritize your thinking when it comes to purchasing food, preparing meals or even eating out! You won’t be like a rat trapped in a maze anymore.

What I am about to share are two methods for determining your nutrient ratios based on the 1-2-3 rule.

Method 1

If you were any good at math, you can see that the 1-2-3 rule adds up to 6 parts. 1 part fat, 2 parts protein and 3 parts carbohydrates add up to 6 total parts. That is about the number of times per day you should be eating. Small but frequent meals that you might have read about elsewhere.

First, dividing up the number 3,000 in our example by 6 will give you 500 calories per part.

Second, knowing that one part equals 500 calories we can figure out the number of calories for each part based on the 1-2-3 rule-of-thumb.

Fat: 1 part x 500 = 500 calories allotted to fat
Protein: 2 parts x 500 = 1000 calories allotted to protein
Carbs: 3 parts x 500 = 1500 calories allotted to carbs

Note: If you don’t know how many calories are in fat, protein and carbs, let me show you really quick so we can continue on with figuring the proper ratios. You’ll use this later to keep it handy.

Fat = 9 calories per gram
Protein = 4 calories per gram
Carbohydrates = 4 calories per gram

Finally you should begin to notice that if you take the calories allotted to each part and divide that number by the numbers above you get:

Fat Calories: 500/9 = 55g of fat
Protein Calories: 1000/4 = 250 grams of protein
Carbohydrate Calories: 1500/4 = 375 grams of carbs

Figuring out the ratios at this point is just as easy as dividing the nutrient totals by the overall calorie totals.

For example, 500 fat calories / 3000 overall calories = 16% fat. Carrying on you’ll see this is broken down into:

Fat: 17% (rounded up)
Protein: 33%
Carbs: 50%

How’s that for determining your own custom ratio? Now you know how to figure out how many grams of what nutrient you need per day using this simple rule.

Using a diet tracking program, that task should be as easy as cutting a fresh apple pie! But we aren’t finished yet…

Method 2

But what if you don’t want to just follow the simple 1-2-3 rule to lose weight? What if you really want to build muscle and you know you will need more protein?

That’s where you simply modify the above rules to ensure protein is the #1 factor in your calculations. If you’re thinking you have to reverse the formula, you are right but it’s easy if you know how.

Example: Male, 200 lbs, 15% body fat, competitive athlete; using 1.14 grams of protein per lb of body weight for this example.


1.14 x 200 lbs = 228 grams of protein a day. If you recall, we know that protein has 4 calories per gram right?
228 grams x 4 calories per gram = 912 calories from protein
Based on the daily calorie needs we used above, 912 protein calories / 3000 overall calories = 30%
30% of the overall calories we need a day are from protein.


While the RDA might recommend 30% or less of your calories from fat, keep in mind the 1-2-3 rule which states that 1 part is fat.

1 part in this guideline is roughly 16.6% (but we’ll just round that up for now).
All this means is you want to get 17% of your total daily calories from fat.
17% x 3000 total daily calories = 510 calories from fat…

Are you with me still?

Let’s figure out how many grams that is simply by recalling that a gram of fat is 9 calories.

So 510 fat calories / 9 calories per gram = 56 fat grams per day!

Note: This may be a reduction for some people considering that it’s quite possible you were getting 50% of your total calories from fats. If this is the case, you might just have to adjust the ratios at this point so it’s not too drastic of a change. Slow and steady changes win the race.

Let’s keep going.


3000 daily calories – 510 fat calories – 912 protein calories = 1578 carb calories.
Again, if you recall there’s 4 calories in a gram of carbohydrates.
1578 carb calories / 4 calories per gram = 395 grams of carbs per day.

If you ever wanted to know the specific ratios, it’s just as simply as taking the nutrient calories divided by the number of overall calories.

In this example, 1578 carb calories / 3000 daily calories = 52%. So 52% of your overall daily calories come from carbs. You can do the same formula for the rest to see the exact nutrient percentages as shown in Method 1 above.

Hopefully you are still reading and if you are then just remember no matter if you use Method 1 or Method 2 of the 1-2-3 rule-of-thumb that is 1 part fat, 2 parts protein and 3 parts carbohydrates, it’s valid for most people who are trying to melt fat while exercising. The rule can be changed to allow for muscle gain or fat loss.

Make determining an appropriate nutrient ratio effortless and make your nutritional thinking easy when purchasing food, preparing meals or eating out with the breakthru methods in the Beginner’s Guide to Fitness & Bodybuilding.

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Marc David is a bodybuilder, writer, and author of the the e-book “The Beginner’s Guide to Fitness and Bodybuilding” (BGFB): What Every Beginner Should Know but Probably Doesn’t. Marc has written over 20 articles and has been featured in several health and fitness websites. Marc’s opinionated and informative articles on bodybuilding, weight loss and training are featured regularly on: www.freedomfly.net