I’ve recently been asked to explain the difference between a Low Carb High Protein (LCHP) diet and the new P:E Diet, and that is the purpose of this article. While both these diets prioritize protein, the recommended macros are very different. This article outlines these two approaches and highlights the similarities and difference between the macro recommendations of these two diets.

Defining Terms

In order to describe how these two diets are similar and different, it is necessary to define some terms — specifically

(1) “low carb“, “keto” and “moderate carb”

(2) “low fat”

(3) “high protein”

Defining Carbohydrate Intake

Feinman et al [1] define very low carbohydrate (”keto”) diet, low carbohydrate diet and moderate carbohydrate diet as follows:

1. very low carbohydrate (keto) diet: 20—50g carbohydrate /day, < 10% total energy intake

2. low carbohydrate diet: < 130g carbohydrate / day, < 26% of total energy intake

3. moderate carbohydrate diet: 130—225g carbohydrate / day, 26—45% of total energy intake

Since these same cut offs for carbohydrate are used by diabetes associations around the world — including the American Diabetes Association, European Association for the Study of Diabetes (EASD), Diabetes Australia, and Diabetes Canada, I use these established definitions, as well.

Defining “Low Fat”

A low fat diet is defined by the USDA as ”not more than 30% of calories from fat” [2].

Defining “High Protein”

Lower and Higher protein diets were defined in a very recent systematic review and meta-analysis[3] with some overlap;

- Lower Protein Diets provide 10-23% of calories from protein
- Higher Protein Diets provide 20-45% of calories from protein

The P:E Diet

P:E Diet -the book

I’ve read the P:E Diet book and find that it provides excellent guidance for healthy individuals who are seeking to build muscle, and lose excess fat. For those seeking to accomplish those goals, the P:E diet is excellent as it encourages people to eat the best quality protein for the least amount of energy (as fat + net carbs).

That said, as I have covered in previous articles and will elaborate on below, I am concerned that the total amount of protein generated in the P:E Macro Generator associated with the P:E Diet (located at the bottom of www.p2eq.com) can get close to the maximum rate at which the kidney can get rid of nitrogen waste from protein in the urine.

I also have concerns that the P:E Macro Generator associated with the diet provides a carbohydrate intake of >100 g of carbohydrate per day to up to >160 g carbohydrate per day which is fine for healthy individuals, but may be inappropriate for someone who is metabolically unhealthy, especially having difficulty with higher than normal blood sugar levels. There is a clear disclaimer at the beginning of the book that it is not intended for those with health conditions, but none on the P:E Macro Generator.

Recommended Macros for the P:E Diet

The P:E Diet Macro Calculator associated with the P:E Diet is located at the bottom of www.p2eq.com recommends 40% protein and 30% fat and 30% carbohydrate for males or females of different heights. Recommended weight generated by the Macro Calculator is set to Ideal Body Weight (i.e. a BMI of 22) which is halfway through the normal weight category.

Below are some examples of macros from the P:E Macro Generator for different heights for both genders;

Carbohydrate recommendation for a man who is 5’7″ tall are at the low end of the moderate carbohydrate range — providing 131 g of carbs / 30% of total energy intake — where moderate carbohydrate is defined as 130—225g carbohydrate / day, 26—45% of total energy intake.

Fat recommendation of 30% calories as fat is low fat, i.e. ”not more than 30% of calories from fat”.

Protein recommendation of 40% calories as protein is a High Protein Diet i.e. provides 20-45% of calories from protein.

Macros for a man who is 5’10” tall are in the moderate carbohydrate range — providing 144 g of carbs / 30% of total energy intake — where moderate carbohydrate is defined as 130—225g carbohydrate / day, 26—45% of total energy intake.

Fat recommendation of 30% calories as fat is low fat, i.e. ”not more than 30% of calories from fat”.

Protein recommendation of 40% calories as protein is a High Protein Diet i.e. provides 20-45% of calories from protein.

Macros for a woman who is 5’6″ tall are in the low carbohydrate range — providing 117 g of carbs / 30% of total energy intake — where low carbohydrate is defined as < 130 g carbohydrate / day, < 26% of total energy intake.

Fat recommendation of 30% calories as fat is low fat, i.e. ”not more than 30% of calories from fat”.

Protein recommendation of 40% calories as protein is a High Protein Diet i.e. provides 20-45% of calories from protein.

Macros for a man who is 6’2″ tall are in the middle of the moderate carbohydrate range — providing 162 g of carbs / 30% of total energy intake — where moderate carbohydrate is defined as 130—225g carbohydrate / day, 26—45% of total energy intake.

Fat recommendation of 30% calories as fat is low fat, i.e. ”not more than 30% of calories from fat”.

Protein recommendation of 40% calories as protein is a High Protein Diet i.e. provides 20-45% of calories from protein.

Summary of P:E Macros

For the most part, carbohydrates in the P:E Diet are in the moderate carbohydrate range, although are on occasion they are in the high end of the low carbohydrate range, or at the low end of the moderate carbohydrate range [1].

The P:E Diet is a Low Fat Diet as it provides ”not more than 30% of calories from fat” [2].

The P:E Diet is a High Protein Diet providing 40% of calories from protein which is in the 20-45% of calories from protein range [3].

Recommended Macros for Low Carb High Protein Diet

As outlined in the previous article, the way I have taught a Low Carb High Protein (LCHP) diet the past 3 years is that protein is set at 25-30% protein (to a maximum of 2.5-3.0 g protein per kg ideal body weight), fat at 65-70% fat and carbohydrate at 10% carbs. This is at the high end of the protein range recommended by Phinney and Volek [7] of 20% to up to 30% of daily calories as protein — and fat is the same as they recommend, at 65-70% fat and 10% carbs.

A Low Carb High Protein diet is always low carb or very low carb; low carb when it contains <130g carbohydrate per day, < 26% of total energy intake, and very low carb (‘keto‘) when it contains 20—50g carbohydrate /day, < 10% total energy intake.

A Low Carb High Protein diet is a High Fat Diet as it provides 65-70% fat, which is ”more than 30% of calories from fat” [2]. Unlike the popularized Low Carb High Fat diet, most of the fat in a Low Carb High Protein Diet comes from the fat inherent in the protein eaten — such as the fat in high fat fish like salmon and tuna, fat in Greek yogurt or the fat that comes in ground beef. There is very little added fat, since a Low Carb High Protein Diet is often used for weight loss.

A Low Carb High Protein diet is a High Protein Diet providing 25-30% of calories from protein [3] to a maximum of 2.5-3.0 g protein per kg ideal body weight, and which is in the 20-45% of calories from protein range of a High Protein Diet [3].

Important Differences Between Low Carb High Protein and P:E Diet

From my perspective, there are two significant differences between a Low Carb High Protein diet and the P:E Diet.

The first significant difference is that the P:E Diet may be low carb — but for the most part is a moderate carbohydrate diet. For those who are metabolically healthy, a diet which provides a carbohydrate intake of >100 g of carbohydrate per day to up to >160 g carbohydrate per day as real, whole (cellular) food is fine. My concern is that for those who already have pre-diabetes or type 2 diabetes, a carbohydrate intake of >100 g carbohydrate per day up to >160 g per day is not the best way to improve blood sugar levels.

As outlined in the American Diabetes Association’s April 2019 Consensus Report a low carb diet has ”demonstrated the most evidence for improving glycemia (blood sugar) for individuals with diabetes”[4].

A Low Carb High Protein diet is, by definition, a low carb diet — so it has demonstrated the most evidence for improving blood sugar.

The second significant difference between a Low Carb High Protein Diet and the P:E Diet is that protein in the P:E Diet is set at 40% of daily calories — and as described in this earlier article, for some heights and weights, the P:E Macro Calculator generates protein at the high end of the maximum protein intake of 3.2 g protein per kg ideal body weight.

When protein is eaten, the body must get rid of the nitrogen by-product and the main way the body gets rid of this nitrogen is by turning it into ammonia, and then excreting it as urea in the urine. Since 84% of the nitrogen waste produced from protein intake is excreted as urea in the urine [5], the safe upper limit of protein intake is based on the maximum rate of urea production which is 3.2 g protein per kg body weight [6], described in more detail in this article.

Protein needs should always be calculated as grams of protein per kilogram of body weight of the person and not as a percentage of daily calories e.g. 40 % of daily energy as protein. This is to ensure adequacy and avoid the excess. An intake of 40% of daily calories as protein for one person may be below the safe upper limit of 3.2 g protein per kg body weight, but for another 40% of calories as protein put them right at the upper limit (more in this article).

By the P:E Diet Macro Generator setting protein intake at 40% of daily calories without limiting a maximum to below the safe upper limit of 3.2 g protein per kg body weight, the protein recommendations generated may sometimes be at the very upper limit.

The Low Carb High Protein Diet, the way I teach it sets protein at 25-30% of daily calories — with a maximum of 2.5 g protein per kg ideal body weight, which is below the safe maximum intake level.

Different Diets for Different Purposes

The P:E Diet is geared towards healthy people seeking to build muscle and lose fat, and as indicated on page 85;

“all bodybuilders are really combining low carb AND low fat AND high protein to the very highest level of success.“

That is what the P:E Diet Macro Calculator located at the bottom of www.p2eq.com is set to do!

It generates macros that are 40% protein, 30% fat and 30% carbohydrate.

A diet that is 30% carbohydrate IS “low carb” when compared with the 45-65% carbohydrate range of the US or Canadian dietary guidelines AND low fat (“”not more than 30% of calories from fat” AND high protein (40% of daily calories as protein) and this is by design.

A Low Carb High Protein Diet, the way I teach it (and as conceptualized by Phinney and Volek in their book) is primarily a therapeutic diet aimed at improving metabolic health including high blood sugar, insulin resistance and for weight loss.

The P:E Diet book is not directed at those who have medical conditions such as pre-diabetes or type 2 diabetes, or for those who have higher than normal blood sugar.

These are very different diets, for very different purposes.

Final Thoughts…

I think the P:E Diet as outlined in the book provides excellent guidance for healthy individuals seeking to build muscle and lose excess fat and P:E ratio as a concept is excellent — encouraging people to eat the best quality protein for the least amount of energy (as fat + net carbs).

I also find that the tool for looking up the P:E ratio of individual foods (at the same link as the Macro Generator, except at the top of the page) is very helpful and saves people from having to do the math to determine Protein / (Fat + Net Carbs).

That said, I am concerned that total amount of protein in the P:E Macro Generator is not limited to a maximum of 3.0 g protein / kg ideal body weight — to ensure it does not exceed the 3.2 g protein / kg ideal body weight (the rate at which the kidney can get rid of nitrogen in the urine). This could easily be done, given that the weight it generates is already set at Ideal Body Weight.

For those who are metabolically healthy, the P:E Macro Generator which provides a carbohydrate intake of >100 g of carbohydrate per day to up to >160 g carbohydrate per day as real, whole (cellular) food is fine, but my concern is that this level of carbohydrate intake may be inappropriate for someone who is already metabolically unhealthy — especially for someone with prediabetes or type 2 diabetes or challenges with higher than normal blood sugar. This could easily be solved by providing a clear disclaimer such as the one that appears in the book.

More Info?

I design low carb Meal Plans from a variety of perspectives, including a Low Carb High Protein and can help individuals decide between different approaches based on their health, goals and nutritional needs.

For those who are metabolically healthy, I also design Meal Plans from a P:E perspective, however I do limit maximum protein intake to a maximum of 2.5 g protein per kg of ideal body weight.

If you would like more information, please send me a note using the Contact Me form on the tab above.

To your good health!

Joy

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References

Feinman RD, Pogozelski WK, Astrup A, Bernstein RK, Fine EJ, Westman EC, et al. Dietary Carbohydrate Restriction as the First Approach in Diabetes Management: critical review and evidence base. Nutrition. 2015;31(1):1—13
Institute of Medicine (US) Committee on Examination of Front-of-Package Nutrition Rating Systems and Symbols; Wartella EA, Lichtenstein AH, Boon CS, editors. Front-of-Package Nutrition Rating Systems and Symbols: Phase I Report. Washington (DC): National Academies Press (US); 2010. Appendix B, FDA Regulatory Requirements for Nutrient Content Claims. Available from: https://www.ncbi.nlm.nih.gov/books/NBK209851/
Vogtschmidt YD, Raben A, Faber I et al, Is Protein the Forgotten Ingredient: Effects of higher compared to lower protein diets on cardiometabolic risk factors: a systematic review and meta-analysis of randomised controlled trials, Atherosclerosis, May 25, 2021, DOI:https://doi.org/10.1016/j.atherosclerosis.2021.05.011
A Consensus Report, Diabetes Care, Ahead of Print, published online April 18, 2019, https://doi.org/10.2337/dci19-0014
TomeÌ D, Bos C, Dietary Protein and Nitrogen Utilization, The Journal of Nutrition, Volume 130, Issue 7, July 2000, Pages 1868S—1873S, https://doi.org/10.1093/jn/130.7.1868S
Rudman D, DiFulco TJ, Galambos JT, Smith RB 3rd, Salam AA, Warren WD. Maximal rates of excretion and synthesis of urea in normal and cirrhotic subjects. J Clin Invest. 1973;52(9):2241-2249. doi:10.1172/JCI107410
Volek JS, Phinney SD, The Art and Science of Low Carbohydrate Living: An Expert Guide, Beyond Obesity, 2011
Naiman T, Shewfelt W, The P:E Diet – Leverage Your Biology to Achieve Optimal Health, June 10, 2020, 330 pages

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