How To Get All Your Nutrition From Food

Macronutrient Ratios

When attempting to avoid multivitamin use and instead get all your nutrition from food, it is necessary to keep a number of things in mind. The first item is to figure out how many calories to eat in a day. Now that we've figured out that I need 2100 - 2500 calories in a day, we can begin the next step, which is to figure out how those calories should be distributed among the macronutrients.

Macronutrients are basically: protein, carbs, and fat. Now there are a lot of different ideas out there as to how to adjust these macronutrient ratios for better health and for weight loss. One of the curious things I have noticed, is that these often do not overlap. That is to say, the ratios being recommended for weight loss are often different than those which seem to be the best for overall health. But I will leave that discussion for another day.

Here I must admit that I have a certain bias, and that bias is toward balance. It's sort of a principle that I live by which says: Unless presented with strong evidence to the contrary, assume that the ideal ratios between conflicting things are those which represent an overall balance. So, we're going to go with the balanced diet approach here.

So what exactly is a balanced diet? I think it might surprise many people. But according to the most basic definition, a balanced diet would be equally distributed between protein, carbs, and fat. However, because I believe there is strong evidence to believe that that a relative excess of carbohydrate is most healthful for the body, we will go with 30% protein, 40% carbs, and 30% fat.

Now here is another sticky point, but I will help you through it. We need to think a little more about this word "balance" because, remember, we are attempting to use three different units in our discussion: calories, cups, and grams. Cups represent volume, while grams represent weight. But when we are talking about a "balanced diet" we are calories as the unit of comparison. Therefore, what may appear to be "balanced" according to weight or volume may not be balanced according to calories, due to differences in caloric density.

The second thing to discuss here is protein. Protein is different from the other two macronutrients because, generally speaking, the body cannot manufacture protein. It can manufacture fats and carbs, mostly through metabolic pathways that convert one into the other. However, interconversion of fats and carbs requires enzymes (which are made from protein) and micronutrients in order to function properly.

Therefore, it is reasonable to assume that, if the body were receiving insufficient levels of either protein or micronutrients, the interconversion of fats and carbs would be impaired, likely resulting in manifestations of deteriorating health. However, to the best of my knowledge, this is just a theory.

Now- we also have to chat for a minute about exercise. Since exercise is, by definition, an increase in bodily activity, it increases the nutritional requirements. In particular: protein. Which is why we need to make another adjustment to our calculation of macronutrient ratios.

Luckily, these numbers are also known to science. We know that the minimal amount of protein necessary to compensate for normal metabolic losses of nitrogen is about 3/4 of a gram of protein per kilogram body weight. For a "lightly active" person like me, that number is increased to about 1 gram of protein per kilogram body weight. For the "moderately active" about 1-1/4 grams per kg, and for the "heavily active" 1-1/2 grams per kg. Gym rats, marathon runners, etc. are in the 2+ grams range, and may wish to consult a professional.

Alright, so now I need to convert my weight in pounds to kilograms by dividing by 2.2, and that reveals that I need a bare minimum of 70 grams protein perday. Throwing in a "fudge factor" I will select the range of 60 – 80 grams of protein per day

Next I need to interpret what 60 to 80 grams means in the context of my macronutrient ratios. Now one gram of protein is good for 4 calories of energy, so that means my body requires between 240 and 320 calories of protein per day. Interpolating that into my macronutrient parameters reveals that adequate protein intake could float somewhere between 10% and 15%. In knowing that protein is often incompletely digested, and that excess fat is not healthful, I am going to take 5% away from both the protein and fat aspects of the ratio, and give it over to the carbs.

This brings my ratio to: 20% protein, 55% carbs, 25% fat. Which equates to about 100 – 125 grams of protein per day. It is important to note here that the amount of protein in a "balanced diet" is considerably more than the minimum amounts necessary to sustain the body, which may be important information for those who wish to minimize the consumption of protein from animal sources.

But wait- what about the fat? While it perhaps might seem like getting a quarter of our total calories from fat is a lot, it really isn't. In fact, the range for what is generally considered a "low fat" diet is 20 – 30% of total calories from fat. We are coming in right at the middle of that range. So how much fat is that in terms of weight? Keeping in mind that one gram of fat is worth 9 calories of energy, that describes a range of 60 to 70 grams of fat per day.

Finally, keeping in mind that one gram of carbs yield roughly 4 calories of energy, we can determine that the range comes in at about 275 – 350 grams of carbs per day.

Alright, we finally have all the pieces for our basic parameters:

Macronutrient Ratios

Checking back really quick with the Acceptable Macronutrient Distribution Ranges developed by the Institute of Medicine, I can verify that the ratio I came up with as "ideal" fits squarely into the ranges which are provided.

Next Up: Micronutrient Needs.

Last Reviewed: 16-02-07