Thoughts on the Zone Diet

The Zone Diet seeks to create a fixed mix of macros by specifying fat, carbs and protein levels. The starting point is:

The numbers are in percentage of calories. On a “standard” 2000 calorie diet that would be:

  • Carbs = 2000 * 0.40 = 800 calories (200 grams)
  • Protein = 2000 * 0.30 = 600 calories (150 grams)
  • Fat = 2000 * 0.30 = 600 calories (67 grams)

Zone vs Standard American Diet (SAD)

According to the CDC (Trends in Intake of Energy and Macronutrients in Adults From 1999-2000 Through 2007-2008):

In 2007-2008 the average energy intake for men was 2,504 kilocalories (kcals) and for women it was 1,771 kcals.

The average carbohydrate intake was 47.9% of total kilocalories (% kcals) for men and 50.5% kcals for women; average protein intake was 15.9% kcals for men and 15.5% kcals for women; average total fat intake was 33.6% kcals for men and 33.5% kcals for women; and average saturated fat intake was 11.0% kcals for men and 11.1% kcals for women.

That means the Zone Diet is lower in carbohydrates, much higher in protein, and a lower fat than the Standard American Diet (SAD).

Macro SAD (Men) SAD (Women) ZONE Difference
Carb 47.9 50.5 40 Zone Lower
Protein 15.9 15.5 30 Zone Much Higher
Fat 33.6 33.5 30 Zone Lower

The main lever of the Zone then appears to be Protein. Doubling someone’s Protein should do some very good things for their health. Added to that is the advantage of the lower number of total calories on the zone.

But would the Zone be a good thing for a Type 2 Diabetic? Certainly it would help some who are diagnosed as pre-diabetic. Anything they do to reduce their carbohydrate consumption will help their pre-diabetes.

Zone vs Ketogenic Diet

The Ketogenic diet has various protein goals depending on you who follow. For a 200 lb male typical numbers would be (using a higher level of protein in this example):

Macro grams kCal/macro Calories % Cals
Carb 20 4 80 4%
Protein 160 4 640 32%
Fat 142 9 1280 64%

Where the two diets differ are their fat and carbohydrate macros.

Macro ZONE Ketogenic
Carb 40% 4%
Protein 30% 32%
Fat 30% 64%

Carbohydrate Effects on a Type 2 Diabetic

Carbohydrates raise blood sugar and therefore Insulin levels much more dramatically in a Diabetic than in a non-Diabetic person. That’s what makes a person an Diabetic. Before I went on the Ketogenic diet I was averaging only 100 grams of carbohydrates per day. I know this since my Insulin pump required me to enter any carbohydrates I ate. And, in spite of being on an average of 100 units of Insulin a day, my blood sugars were all over the place.

My highs were over 200 and my lows never got to 100. Around the start of August I went on the Ketogenic diet. For me, that was going from 100 grams (on the average) of carbohydrates a day to less than 20 grams. I was also not tracking the other macros (fat, protein). Here are my blood sugar numbers from the first three months of the Ketogenic diet.

That chart is the very definition of stable blood sugars. It took being at 20 grams or less of carbs a day to get stable. And before the Ketogenic diet I was nowhere near the Zone Diet carbohydrate levels. I can only imagine how messed up my blood sugar numbers would have been if I had been on the “balanced” zone diet.


Protein Requirements by Type of Workout

The conventional wisdom is that 20-25 g of Protein is optimal at a meal for Protein Muscle Synthesis has been challenged by a recent study. Turns out that most of the previous studies looked at exercise of isolated muscle groups rather than whole body resistance exercise.

The study (Physiol Rep. 2016 Aug; 4(15): e12893. The response of muscle protein synthesis following whole‐body resistance exercise is greater following 40 g than 20 g of ingested whey protein. Lindsay S. Macnaughton, Sophie L. Wardle, Oliver C. Witard, Chris McGlory, D. Lee Hamilton, Stewart Jeromson, Clare E. Lawrence, Gareth A. Wallis, and Kevin D. Tipton) took a look at how much Protein is optimal at a meal after larger muscle group exercise. The conclusion?

Our data indicate that ingestion of 40 g whey protein following whole‐body resistance exercise stimulates a greater MPS response than 20 g in young resistance‐trained men.

Since the subjects of this study were young trained men who were healthy this may even be more true with older, untrained and diabetic individuals. See  (British Journal of Sports Medicine. A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength in healthy adults. Robert W Morton, Kevin T Murphy, Sean R McKellar, Brad J Schoenfeld, Menno Henselmans, Eric Helms, Alan A Aragon, Michaela C Devries, Laura Banfield, James W Krieger, Stuart M Phillips.)

Dietary protein supplementation significantly enhanced changes in muscle strength and size during prolonged resistance exercise training (RET) in healthy adults. Increasing age reduces and training experience increases the efficacy of protein supplementation during RET. With protein supplementation, protein intakes at amounts greater than ~1.6 g/kg/day do not further contribute RET-induced gains in FFM.


Healing Diabetic Neuropathy

In diabetic neuropathy, one of the most common forms of peripheral neuropathy, nerve damage occurs in an ascending pattern. The first nerve fibers to malfunction are the ones that travel the furthest from the brain and the spinal cord. Pain and numbness often are felt symmetrically in both feet followed by a gradual progression up both legs. Later, the fingers, hands, and arms may become affected. (Peripheral Neuropathy Fact Sheet).

Is this a permanent condition?

It is a progressive condition which gets worse. The only solution is to reverse the underlying diabetes. That’s where Low Carb comes in. Once the underlying condition gets reversed the body begins to repair/regrow the nerves. Nerves can regrow around 1 mm/day. The growth starts at the spine and goes to the extremities. So neuropathy in the feet or hands can be reversed in around three years or so.


Protein Timing – Bro-Science?

Protein timing is the question of how long after you workout should you eat protein. Until fairly recently, conventional wisdom was that there was a 30-60 minute window to eat protein after a workout to maximize protein muscle synthesis.

Here’s a good article on Protein timing (The New Rules of Protein Timing) which states that there’s newer science which indicates that the window is wider and also affected by what you ate earlier.

Here’s one of the studies (Human Kinetics Journals, Volume 19 Issue 2, April 2009. Effect of Protein-Supplement Timing on Strength, Power, and Body-Composition Changes in Resistance-Trained Men . Jay R. Hoffman, Nicholas A. Ratamess, Christopher P. Tranchina, Stefanie L. Rashti, Jie Kang, Avery D. Faigenbaum).

Results indicate that the time of protein-supplement ingestion in resistance-trained athletes during a 10-wk training program does not provide any added benefit to strength, power, or body-composition changes.

Here is another similar result from analysis of many studies (Journal of the International Society of Sports Nutrition 2013 10:53, The effect of protein timing on muscle strength and hypertrophy: a meta-analysis. Brad Jon SchoenfeldEmail author, Alan Albert Aragon and James W Krieger.):

These results refute the commonly held belief that the timing of protein intake in and around a training session is critical to muscular adaptations and indicate that consuming adequate protein in combination with resistance exercise is the key factor for maximizing muscle protein accretion.


Protein Sparing Modified Fast (PSMF)

There’s a lot of scientific data concerning Protein Sparing Modified Fasts (PSMF).

Here’s one article (Nitrogen Metabolism and Insulin Requirements in Obese Diabetic Adults on a Protein-Sparing Modified Fast), ).

When this fast was applied to seven obese adult-onset diabetics who were receiving 30–100 units of insulin per day, insulin could be discontinued after 0–19 days (mean, 6.5). In the three patients who had extensive nitrogen-balance studies, balance could be maintained chronically by 1.3 gm. protein per kilogram IBW, despite the gross caloric inadequacy of the diet. The PSMF was tolerated well in an outpatient setting after the initial insulin-withdrawal phase had occurred in the hospital. Significant improvements in blood pressure, lipid abnormalities, parameters of carbohydrate metabolism, and cardiorespiratory, symptoms were associated with weight loss and/or the PSMF. For diabetics with some endogenous insulin reserve, the PSMF offers significant advantages for weight reduction, including preservation of lean body mass (as reflected in nitrogen balance) and withdrawal of exogenous insulin.

Another paper (Multidisciplinary treatment of obesity with a protein-sparing modified fast: results in 668 outpatients. A Palgi, J L Read, I Greenberg, M A Hoefer, B R Bistrian, and G L Blackburn – Full Text) showed excellent results. Here’s the abstract:

Six hundred sixty-eight obese outpatients, 71 per cent (+/- 34) in excess of ideal weight, were enrolled in a multidisciplinary weight control program. The major components of the program included nutrition, education, behavior modification, and exercise. Rapid weight loss was accomplished using a very low calorie (less than 800 kcal) ketogenic diet. Patients adhered to the protein sparing modified fast (PSMF) for 17 +/- 12 weeks and averaged 9 +/- 17 weeks in a refeeding/maintenance program. Mean weight loss was 47 +/- 29 lb (21 +/- 13 kg) at the point of minimum weight and 41 +/- 29 lb (19 +/- 13 kg) at the end of the maintenance period. Systolic and diastolic blood pressure and serum triglycerides fell significantly in men and women. Success in weight loss was greatest in the heaviest patients, those who adhered the longest to the PSMF, and those who stayed the longest in the maintenance program.


Protein-Sparing Modified Weight Loss Studies

There’s a lot of scientific data concerning Protein Sparing Modified Fasts (PSMF). In this post will collect together studies which looked at Protein Sparing Modified Fasts. I expect to add studies to this page over time.


Genetic Muscular Potential

Here’s a calculator for Genetic Muscular Potential (YOUR Drug-Free Muscle and Strength Potential: Part 2). This is useful to know what your current condition is as well as what is possible with the most training possible.

The units are not American (lbs, inches) but are Metric (kg, cm).

I put in my numbers:

  • Height: 5′ 10.5″ = 197 cm
  • Wrist Circumference: 15.24 cm
  • Ankle Circumference: 21.6 cm

Genetic Muscular Potential Results

  • Maximum Lean Body Mass: 79 kg = 174 lbs
  • Bodyweight at Maximum Muscular Potential: 89.8 kg = 198 lbs

The Calculator goes on to tell you how far from goal you are presently. The results came back as:

  • Current body fat percentage: 19.7% (seems too low)
  • Current Lean Body Mass: 66.3 kg = 146 lbs
  • Fat mass I should lose: 5.5 kb = 12 lbs
  • Lean mass I could gain: 12.7 kg = 28 lbs

Those 28 lbs of potential lean mass would be over many years of weightlifting.


How Much Glycogen Stores in Low Carb?

It’s often claimed that Glycogen stores are reduced in Low Carb diets. I wondered by just how much and there’s a paper out there which has specific numbers in it (Scandinavian Journal of Clinical and Laboratory Investigation Volume 32, 1973 – Issue 4. Pages 325-330. Liver Glycogen in Man –- the Effect of Total Starvation or a Carbohydrate-Poor Diet Followed by Carbohydrate Refeeding. Depts. of Gastroenterology and Clinical Chemistry, L. Hson Nilsson & E. Hultman, S:t Eriks Sjukhus, Stockholm, Sweden & E. Hultman).

Liver glycogen content was determined in specimens obtained by repeated percutaneous biopsies during starvation and under various dietary conditions in 19 human subjects. During rest and following an overnight fast, there was a decrease in liver glycogen content by a mean of 0.30 mmol glucosyl units per kg wet liver tissue per min during a further 4 hours’ starvation. Prolonged starvation or carbohydrate-poor normocaloric diet decreased the liver glycogen from a mean of 232 to 24–55 mmol glucosyl units per kg within 24 hours. During an additional period of up to 9 days on the carbohydrate-poor diet the liver glycogen remained at a low level. Refeeding with a carbohydrate-rich diet gave a rapid increase of the liver glycogen to supernormal values, 424–624 mmol glucosyl units per kg wet liver tissue.

Wow! That’s a pretty dramatic drop in liver glycogen in just 24 hours.

Glycogen Refill

Maybe even more amazing is the very fast refill to 2x-3x the “normal” levels. That goes a long way to explaining weight gain when leaving the Low Carb diet.

As a reference on the liver (Clinical Methods: The History, Physical, and Laboratory Examinations. 3rd edition.Chapter 94 Evaluation of the Size, Shape, and Consistency of the Liver. Douglas C. Wolf.)

The liver weighs 1200 to 1400 g in the adult woman and 1400 to 1500 g in the adult man.

According to this article:

Liver glycogen provides about 400 calories or 100 grams of glycogen

If there’s 3-4 grams of water with every gram of glycogen that’s a total of 400-500 grams that are lost with reduction in glycogen. That’s less than 1 lb but a significant portion of a typical liver size (around 1/3 of the size).