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Why The Paleo Diet Doesn’t Focus on Macronutrients

One of the main criticisms of The Paleo Diet® is that there is no defined macronutrient profile.

It’s true that we don’t specify exact portions or percentages of carbs, protein, and fat in our diet. But there is a good reason for this! The Paleo Diet is all about mimicking the way our hunter-gatherer ancestors ate, as closely as possible. However, their diets came with a lot of variabilities. Depending on where they lived and what was available to them, their diets looked very different.

Though we have access to all kinds of foods today, we are individuals with different dietary needs and seasonal availability. So why try to stick to a set macronutrient profile that has previously never existed, when variability is a part of life?

Defending our position

A few years ago, we interviewed Dr. Caroline Apovian, former Director of the Nutrition and Weight Management Center at Boston Medical Center, to hear out her criticisms of The Paleo Diet.

In the interview, Dr. Apovian spoke about how we had not stipulated a set ratio of fats, carbohydrates, and protein. While most popular diets recommend macronutrient percentages, we explained that The Paleo Diet does not because the diets eaten by our ancestors were varied by region and time of year. It’s not possible to represent them all by one single diet or a defined set of macronutrients.

Instead, The Paleo Diet focuses on emulating the foods that were and were not eaten by our ancestral hunter-gatherer societies. A thorough examination of the research on hunter-gatherer societies shows that they universally ate a mix of plant and animal foods (in different ratios) and did not eat grains, legumes, dairy, and, of course, the highly processed foods we see today.

A closer look at hunter-gatherer societies

How do we know what hunter-gatherers really ate? Because the hunter-gatherer mode of life is essentially now extinct in its pure form, we must turn to studying traditional preagricultural diets by examining the ethnographic, fossil, or archaeologic records. Combining these studies with modern-day nutrient analysis of wild plant and animal foods can then approximate ancient diets.

Dr. Loren Cordain, the founder of The Paleo Diet movement, published a seminal paper in the American Journal of Clinical Nutrition that analyzed data on 229 hunter-getherer societies. [1] This publication used the updated and revised Murdock’s Ethnographic Atlas—a highly respected record of untouched hunter-gatherer societies. [2]

In the study, Dr. Cordain and his colleagues looked at gathered plant foods, hunted animal foods, and fished animal foods to determine the composition of hunter-gatherer diets. Generally, they found a high reliance on animal-based foods. As a result, while the diets varied, protein was elevated (19–35 percent of energy). Also, since wild plant food had relatively low carbohydrate (CHO) content, the CHO ratio of their diets was low (22–40 percent of energy).

A varying mix of plant and animal foods

All of the hunter-gatherer societies that were studied ate a mix of plant and animal foods. Most (58 percent) fell within a range of plant to animal subsistence ratios from 35:65 to 65:35.

The data showed that 73 percent of the worldwide hunter-gatherers derived 56–65 percent of their subsistence from animal foods (hunted and fished), whereas only 13.5 percent derived 56–65 percent of their subsistence from gathered plant foods. Fifty-six percent obtained greater than 66 percent of their subsistence from animal foods in contrast with only 4 percent of societies that obtained greater than 66 percent of their subsistence from gathered plant food.

No hunter-gatherer population was largely or entirely dependent (86–100 percent) on gathered plant foods, whereas 20 percent were largely or almost entirely dependent (86–100 percent) on fished and hunted animal foods.

In other words, their diets generally appeared to be more meat-centric than plant-based.

Why was this? It was a combination of factors, including availability. Since plant food is less available at extreme latitudes (far north or far south), hunter-gatherer societies in these locations naturally ate less of it.

While the ranges of plant to animal foods varied from one society to the next, one thing remained constant: year-round, none were entirely carnivorous, and certainly none were vegan.

How hunter-gatherers foraged for an optimal diet

Another reason that the diets tended to be higher in meat than plants is what anthropologists refer to as the “optimal foraging theory.”

This simply means that foods were hunted, gathered, and fished in a manner that maximized their caloric intake versus the energy they expended to obtain them. In other words, there’s no point collecting food that takes more energy to collect than it gives you from eating it.

This led to the following general order of food preference: large animals; medium-size animals; small animals, birds, and fish; roots and tubers; fruit; honey; nuts and seeds. [3] In a study of the gathered plant foods, fruit represented 41 percent of the total number of food items, seeds and nuts represented 26 percent, underground storage structures (tubers, roots, and bulbs) represented 24 percent, and the remaining 9 percent of the food items were leaves, dried fruit, flowers, gums, and miscellaneous.

Balancing protein with fat and carbs

While you don’t need to calculate exact macronutrient ratios in order to eat Paleo, it is important to make sure that you don’t eat too much protein. This can happen when small, very lean animals, such as rabbits, are exclusively consumed.

Humans do not tolerate diets well where more than 35–40 percent of their energy comes from protein. The liver has a finite ability to remove the nitrogen in protein in order to break it down. When protein is eaten in excess, it can sometimes lead to hyperaminoacidemia (an excess of amino acids in the blood) and hyperammonemia (an excess of ammonia in the blood), which can cause brain injury and even death.

Known as “rabbit starvation” or protein poisoning, this malnourished state did become a problem for early explorers. To prevent it, they had to either increase their carbohydrate consumption through plants or increase their fat consumption through fattier animals.

However, because of the food preference of our hunter-gatherer ancestors, dictated by the optimal foraging theory, this was never a problem.

Estimating the hunter-gatherer protein-carbohydrate-fat ratios

Factoring in the need to avoid rabbit starvation and the foods that were generally available to hunter-gatherer societies based on their latitude, hunter-gatherer societies would have eaten macronutrient ratios in the following ranges:

  • 19–35% protein
  • 22–40% carbohydrates
  • 28–58% fat

However, when Dr. Cordain and his colleagues looked at societies that didn’t live at extreme latitudes, the ratios had less variability and looked more like this:

  • 20–31% protein
  • 31% carbohydrates
  • 38–49% fat

In comparison, the typical Western diet is about 15 percent protein, 50 percent carbohydrates, and 34 percent fat, with the remainder coming from alcohol. [4] This doesn’t fit within the range of any hunter-gatherer diet, as the protein is too low, the carbohydrates are too high, and the fat is on the low side. More importantly, even though the macros don’t fit, the bigger issue is that the typical Western diet comprises foods that were never eaten by our hunter-gatherer ancestors, and therefore played no role in the evolutionary development of human physiology.

The bottom line: finding a plant-animal ratio that works for you

Ultimately, the data from Cordain’s seminal study clearly indicate that there was no single diet that represented all hunter-gatherer societies. Consequently, there is no evolutionary or scientific basis to dictate a particular macronutrient breakdown for any diet.

So, what does this all mean for implementing The Paleo Diet in the modern world? Well, given there is clear evidence that hunter-gatherers have consumed a wide variety of plant-animal subsistence ratios, while maintaining healthy lives, it makes sense for people to simply focus on consuming the foods that made up the diets of these societies and our ancestors rather than trying to consume a specific macronutrient percentage.

Also, given the different plant-animal subsistence ratios seen in these hunter-gatherer societies, there could potentially be a genetic component where, based upon someone’s origins, different plant-animal subsistence ratios will provide better results in terms of overall health.

The goal for anyone adopting The Paleo Diet is to find a plant-animal subsistence ratio that works best for you. The data supports having flexibility with respect to how much of your diet comes from plants and how much comes from animals. So long as you are consuming a nutrient-dense diet consisting mainly of animals, vegetables, fruits, and some nuts and seeds, the macronutrient breakdown can be variable for some and specific for others.

The take-home message is that there is no set macronutrient breakdown that is better for the population as a whole. It’s all about what works best for your body and lifestyle.


[1] Cordain L, Miller JB, Eaton SB, Mann N, Holt SH, Speth JD. Plant-animal subsistence ratios and macronutrient energy estimations in worldwide hunter-gatherer diets. Am J Clin Nutr 2000;71(3):682-92.

2. Murdock GP. Ethnographic atlas: a summary. Ethnology 1967;6(2):109–236.

3. Cordain, L. The Paleo Answer: 7 Days to Lose Weight, Feel Great, Stay Young. New Jersey, John Wiley & Sons, Inc.; 2012. 

4. McDowell MA, Briefel RR, Alaimo K, Bischof AM, Caughman CR, Carroll MD, Loria CM, Johnson CL. Energy and macronutrient intakes of persons ages 2 months and over in the United States: Third National Health and Nutrition Examination Survey, Phase 1, 1988-91. Adv Data. 1994 Oct 24;(255):1-24. PMID: 10141689.

Mark J. Smith, Ph.D.

One of the original members of the Paleo movement, Mark J. Smith, Ph.D., has spent nearly 30 years advocating for the benefits of Paleo nutrition.

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