Insulin and Diabetes: A Metabolic Typing Perspective

Human beings are dependent on food for their survival. Without food, we will inevitably die; and if we eat poor quality food, parts of us will die. Awareness of which foods are best for each individual has always been an issue among nutritionally oriented practitioners and the public alike. Every one of us has choices, but few of us have sophisticated knowledge of the foods that are best suited to our own individual metabolism. It is important to understand your own biochemical make-up in order to wisely select the foods which will lead to optimal health. Metabolic Typing provides just such an understanding, and although many decades of research have been devoted to it, we have just begun to scratch the surface.

I consider two of the most important factors for health and longevity to be insulin levels and blood pH. There are  several research scientists and practitioners in particular that I would like to acknowledge for contributing to our understanding of the role of insulin: Professor Gerald Reaven, M.D., Ronald Rosedale, M.D., Richard K. Bernstein, M.D., Barry Sears, Ph.D. and Robert C. Atkins, M.D., and I will be alluding to their work throughout this article. It is important to understand that   there are many hormones that raise blood sugar — such as glucagon, epinephrine (adrenaline), cortisol and human growth hormone — but only one that lowers blood sugar insulin. It has been conjectured that this is because less insulin was needed in the earlier days of human existence, partly because keeping blood sugar levels up was more of an evolutionary imperative than lowering them, and partly because our diet was more centered around animal foods (1). But, with the advent of agrarian foods (primarily cereal crops), we may have developed the need for more insulin to handle the increased carbohydrate load. This may or may not have coincided with the appearance of Type A blood, as D’Adamo has theorized (2).

Insulin is best known for its role as a blood sugar lowering hormone, but it has many other important functions, some of which have potentially negative as well as positive ramifications; these include the following, which are largely drawn from the work of Rosedale (1):

  • Regulates life span
  • Promotes muscle building  (anabolic)
  • Stores protein and nutrients, such as calcium, magnesium and vitamin C
  • Mediates calcium metabolism
  • Mediates IGF-1 (Insulin-like Growth Factor 1)
  • Controls conversion of T-4 to T-3 in the liver
  • Controls testosterone and progesterone secretion
  • Stimulates sympathetic nervous system activity
  • Encourages body fat deposition
  • Mediates blood lipids
  • Stimulates cell proliferation (mitosis)
  • Encourages blood clotting
  • Contributes to the retention of sodium and fluids

Insulin resistance — which primarily occurs in the liver, muscles and fat cells, and which can be exacerbated by caffeine consumption, as well as excess sugar and carbohydrates — leads to elevated levels of circulating insulin, contributing to the following:

  • Premature aging
  • High blood pressure
  • Elevated triglycerides
  • Atherosclerosis
  • Congestive heart failure
  • Inhibition of the release of glycogen (stored glucose) from the liver
  • Development of osteoporosis
  • Reduction of DHEA levels
  • Acceleration of glycation, leading to inflammation and tissue damage
  • Development of malignancies
  • Inhibition of the burning of body fat

Professor Reaven developed the theory of insulin resistance in 1988, though it was not accepted by the  medical community for years, and he later went on to  develop the theory of Syndrome X (also known as Metabolic Syndrome) (3). Prior to this, the conventional explanation of high blood sugar was insufficient production of insulin by the beta cells of the pancreas. Sears claims that as little as 25% of the population can thrive on carbohydrates (4); but it is my contention that  this number is probably closer to 40%. My own work is based around a protocol that tests carbohydrate tolerance, using a specially modified glucose tolerance test that  evaluates whether individuals are better suited to a diet higher in complex carbohydrates and lower in fat and protein (which I refer to as the Group I diet), or to a diet lower in complex carbohydrates and higher in fat and protein (the Group II diet).

The mini-glucose tolerance test is administered following a fast of a minimum of six hours. After taking a fasting blood glucose reading, the client is given a 12-ounce glass of water mixed with approximately 40 grams of pure glucose and 1 gram of potassium. Thirty minutes after the ingestion of the glucose challenge, a second blood glucose reading is taken, followed by third and fourth ones at additional 45- and 20-minute intervals. While our primary purpose in taking these readings is to determine the relative acidity or alkalinity of the blood (which is a key element in determining the individual’s Metabolic Type), they also have a great deal of significance in identifying dysglycemia, insulin resistance and other possible systemic imbalances.

An ideal blood sugar curve might look as follows:

Fasting     +30 mins.    +45 min.   +20 mins.
80                    130                   110                 100

A hypoglycemic curve might look something like this:
65                    170                    80                    55

We are all aware that hypoglycemia is frequently a precursor to Type II diabetes. Hypoglycemics are typically put on our Group II protocol (higher in protein and fat, low in complex carbohydrates). This imbalance can be completely reversed in a matter of weeks, assuming good compliance with the suggested diet and supplement regimen.

The following is a severely diabetic reading:
140                   275                   285                 300

You will note that the fasting glucose reading of 140 is 14 points above 126, the currently accepted threshold for Type II diabetes. Note also the continued escalation of numbers as the test progresses. This is indicative not only of insulin resistance, but possibly also of compromised pancreatic function (beta cell activity). This type of continuously escalating blood sugar readings suggests that the individual might need more than our normal diabetic diet and supplement protocol. Sometimes dietary changes alone will be sufficient to normalize such elevated readings but, if not, pharmaceutical intervention may be required

A diabetic with a more favorable prognosis might appear as follows:
140                   275                   245                 190

The fact that the sugars decrease progressively is a favorable sign, indicating that insulin metabolism is still operating, albeit at a reduced level.

The following blood sugar curve may or may not indicate full-blown diabetes, but certainly it suggests a seriously dysglycemic condition that will almost inevitably evolve into diabetes.
80                    205                   200                   190

The normal fasting glucose in the above example means the patient has good beta cell activity, and is producing adequate insulin. However, lack of insulin metabolism occurs when confronted with a glucose challenge. This has to be addressed by minimizing or avoiding carbohydrate foods that produce a similar effect in the body, such as potatoes, grains, sweet fruits and fruit juices. Sugar and all refined carbohydrates should be completely avoided.

Sometimes, however, we see what appear to be pre-diabetic readings, such as the following, in individuals who have removed refined sugar, sweet fruits, potatoes and other starches from their diet:
80                    190                   140                   110

What we realized over time is that this is an extreme glycemic response that sometimes occurs in a body that has acclimatized itself away from sugar. This is a relatively benign situation that can usually be addressed successfully with lipoic acid (300 mg per day, in divided doses).

It is difficult to distinguish between a lack of beta cell activity and insulin resistance. The only definitive way is to assay blood insulin levels. From a practical standpoint, however, both conditions are addressed the same way.

In my work, as well as the work of several colleagues in the field of Metabolic Typing, I have observed that approximately 70% of diabetics are the Group II Metabolic Types (Fast Oxidizers or Parasympathetics). They require a modified version of the usual Group II diet, which we refer to as the Diabetic Protocol (centered around protein foods, good quality fats, and non-starchy carbohydrates). Often, we even will recommend this same diet to the 30% of Group I diabetics, at least until their blood sugars stabilize, even though this is a very different kind of diet than we would normally recommend to the Group I types.

Syndrome X or pre-diabetic individuals may require either a Group I or Group II diet, depending on their metabolic dominance. We notice the Group I Syndrome X clients    tend to develop cardiovascular problems without also developing diabetes, whereas the Group II Syndrome X individuals tend to develop diabetes itself (which may then further progress into secondary cardiovascular disease). In both scenarios, excessive consumption of sugar, refined grain products and trans-fatty acids (from partially hydrogenated and overheated oils) are often the culprits, frequently in combination with a sedentary lifestyle.

Diabetes is essentially a disease of insulin dysregulation. Either there is too little insulin being secreted from the beta cells of the pancreas (as found in Type I diabetes and, occasionally, in advanced Type II diabetes) or the insulin receptors have lost their sensitivity, leading to a build-up of both insulin and glucose in the bloodstream. In an attempt to compensate for this insulin resistance, the  pancreas secretes even more insulin into the bloodstream to try to force the issue by swamping the insulin receptors (this is the same principle behind the use of insulin injections for Type II diabetics). While this strategy may help somewhat to reduce glucose levels in the bloodstream, it also leads to an overload of insulin, which, in the long term, only exacerbates insulin resistance.

Insulin sensitivity (effective utilization of insulin) and insulin resistance (ineffective utilization of insulin) represent a dynamic polarity we all have to deal with throughout our  lives. Our very health and longevity depend to a great deal on how well our body deals with insulin. Insulin  sensitivity is what we should all strive for, but insulin resistance is increasingly becoming the norm. Rosedale mentions that women who consume large amounts of refined carbohydrates and sugar during pregnancy will often induce insulin resistance in their newborns (1). Could this be a major factor in the increasingly early onset of Type II diabetes, which, until recently, rarely manifested until the middle years?

We are entering into a new era where various versions of the Paleolithic diet are coming into vogue (1) (5), and vegetarianism — once the standard bearer of the  alternative health movement — is going out of vogue. This swing of the pendulum is as potentially erroneous as the opposite swing, half right and half wrong. We know from our work with Metabolic Typing that some individuals do indeed thrive on a Paleolithic type diet (perhaps 60%), but others continue to require a lower protein, more vegetarian-friendly regimen. Happily, this can be easily determined by our Metabolic Typing procedures. For individuals of all Metabolic Types, the major culprits in our diets today are sugar, refined grains, partially hydrogenated and other damaged oils, and the consumption of meat from animals laden with antibiotics and bovine growth hormone, that have been fed soy, corn and grains rather than their natural diet of grass. Free range cattle have a much more favorable ratio of fatty acids than grain-fed cattle, with a higher percentage of essential fatty acids and conjugated linoleic acid (CLA), and a lower saturated fat content (this is not to imply that saturated fat is bad, as it is not; it is simply that a deficit of essential fatty acids can indeed contribute to various degenerative diseases).

The common denominators for optimal health are insulin control and a balanced blood pH. It is my feeling that  when the blood pH is optimal, the individual will no longer have insulin resistance or hyperinsulinemia. There are two primary ways to maintain insulin sensitivity: proper diet (either Group I or Group II foods, depending on the individual’s Metabolic Type); and exercise (which reactivates sluggish insulin receptors). Too much glucose, along with insulin, in the bloodstream can be dangerous for many reasons. Linus Pauling knew that white blood cells need vitamin C to stimulate phagocyte activity to counteract bacteria and viruses. He noted that high blood glucose greatly reduces such activity; in fact, a fasting  blood glucose reading of over 120 mg/dl reduces phagocyte activity by as much as 75% (1). From this alone, it should be obvious why diabetics have so many health problems!

We all owe a debt of gratitude to the researchers and clinicians who have drawn our attention to this critical area of blood sugar control, and I have personally learned much from them. However, I take issue with their varying recommendations for macronutrient ratios. There is no single ideal diet or macronutrient ratio that is right for everyone, and to state otherwise is simply erroneous.

Let me give you an overview of their recommendations:

Rosedale: 20% carbohydrates, 25-30% proteins, and 60-65% fats
Sears:        40% carbohydrates, 30% proteins, and 30% fats
Reaven:   45% carbohydrates, 15% proteins, and 40% fats

Atkins offers a sliding scale, depending on an individual’s weight loss needs (6), while Bernstein alone resists the temptation to present his own macronutrient ratio (7). However tempting it may be to devise a theoretical, universal macro-nutrient ratio, there simply is no such thing, and our work with Metabolic Typing — which emphasizes a relativistic approach to macronutrients — continues to underscore this much overlooked point. Knowing what foods and supplements are best suited to one’s Metabolic Type, thereby promoting optimal blood pH and proper glucose and insulin balance, will go a long towards preventing disease and promoting optimal health and longevity.

Dr. Harold J. Kristal was a pioneer in the emerging field of Metabolic Typing. He is the author of The Nutrition Solution: A Guide to Your Metabolic Type  (North Atlantic Books, December 2002).


  1. Rosedale, Ronald, M.D. Insulin and its Metabolic Effects. Address to Designs for Health Institute Boulder Fest, August 1999
  2. D’Adamo, Peter, Ph.D. Eat Right for Your Type. Putnam, 1997
  3. Reaven, Gerald M., M.D. Syndrome X: Overcoming the Silent Killer that can Give You a Heart Attack. Simon and Schuster, 2000
  4. Sears, Barry, Ph.D. Enter the Zone. Harper Collins, 1995
  5. Cordain, Loren, Ph.D. The Paleo Diet. Wiley, 2002
  6. Atkins, Robert C., M.D. Dr Atkins’ New Diet Revolution. Avon Books, 1992
  7. Bernstein, Richard K., M.D. Dr. Bernstein’s Diabetes Solution. Little Brown, 1997

Note from Life Enthusiast:
When your body gets its required nutrients, it can clean, repair and maintain itself. Find your specific Metabolic Type to determine what foods contribute to your health. And which foods take away your well being. Learn how to construct meals to build health instead of disease.

Metabolic Typing is THE tool you need for optimal health. Feeding your unique body type is the single most important principle that affects your maximum performance in all aspects of life.

Author: Harold J. Kristal, D.D.S.