Metabolism A or B – Which are You? Part 1

Why can some people plough their way through platefuls of food and never gain a gram while others claim they merely have to look at food and they put on weight? The answer, it appears, depends on whether you have Metabolism A or B.

Some people seem to be lucky, in that they can eat what they like and they don’t put on a gram. Others put on a kilogram after eating a piece of cake. The latter used to be blamed for eating too much or being lazy, but now it is usually recognised as being due to differing metabolic rates.


What is metabolism, and are there different kinds of metabolism? Metabolism is a term used to describe the sum total of all the processes going on in the body to maintain life, such as heartbeat, brain function, detoxification, breathing, digestion, etc. One’s metabolic rate will be faster after physical exercise and during pregnancy, and it will be slower if the thyroid gland is under-functioning.

Diane Kress, in her book The Diabetes Miracle, has coined the terms Metabolism A and B (Met A and Met B). Metabolism A is the textbook metabolism, which is presumed to be present in most people. It operates in a hormonal equilibrium, where food is taken in, digested, absorbed and assimilated into the cells in a normal manner. The cells produce energy and growth, the body functions optimally and everything is in balance. If the person eats too much, he/she puts on weight; if he/she cuts the calorie intake, the weight drops.

People with Metabolism B, on the other hand, experience progressive weight gain around the middle, increasing blood pressure, blood glucose, LDL cholesterol (low density lipoprotein), triglycerides, depression, anxiety and fatigue. Met B is also known as metabolic syndrome or Syndrome X. The main difference between Met A and B is in the way the body processes sugars and starches (carbohydrates). Studies have shown that Met B people are born with a genetic propensity, which Met A people do not have.


Although one may be unfortunate to be born with the gene favouring Met B development, it is environmental triggers which cause the condition to manifest. This is the science of epigenetics, whereby the environment determines whether an inherited genetic disposition will be manifested or not. Some of these environmental triggers include stress, overeating (especially sugars and starches), lack of physical exercise, illness, surgery, toxins and certain medicines.

From starchy bun to diabetes

If a Met A person eats a starchy bun, the blood sugar will rise. The pancreas is stimulated to release the correct amount of insulin. The insulin enters the bloodstream in search of muscle and fat cells with insulin receptors. The insulin locks with the receptor like a matching ‘lock and key’ to open the cell, which takes in the sugar. If the person has exercised, the muscle cells will be empty, and will be refilled with sugar. If the person has not exercised the majority of insulin will connect to the fat cells, which will increase in size. When the process is complete, the sugar remaining in the bloodstream is always in the normal range.

However, if a Met B person eats the same starchy bun, the body processes it slightly differently. As the blood sugar rises, the pancreas over-reacts by releasing a little extra insulin (due to the genetic variation). If the person has exercised, the muscle cells will be refilled first. If not, the majority of the insulin will connect to fat cells. The extra insulin attaches to, and opens, extra fat cells, which now also require filling. This leaves the sugar level in the bloodstream a little lower than normal. This low blood sugar level is detected by the brain, which puts out the signal ‘blood sugar too low, eat more starch’. The person may feel hungry or tired, and even irritable, shaky or nauseous, and reaches for another ‘comfort food’. The blood sugar rises and the person feels better, but the vicious cycle repeats itself. This roller-coaster of highs and lows of mood associated with the highs and lows of blood sugar levels, can easily lead to an addiction to comfort foods (which are nearly always starchy or sugary in nature).

Unfortunately, every time this happens, the fat cells grow larger and the insulin receptors also grow larger, while becoming misshapen. When the ‘lock’ no longer fits the ‘key’, the receptors cannot respond to the insulin, and the condition called ‘insulin resistance’ develops.


Insulin resistance means that the body, in its attempt to keep blood sugar levels stable, has to increase the number and size of fat cells, particularly around the waist. This phase of increasing fat deposits with normal blood sugar levels, is often ‘silent’ for many years, and undetected by routine blood testing. It can be recognised by the apple shape the body becomes, which is known to be associated with significantly increased risk of heart disease. If this fat-gain stage is not recognised and controlled, Met B progresses to pre-diabetes, where the over-fed and over-sized fat cells become more resistant to insulin and the blood sugar levels start to increase. If the pre-diabetic state is not recognised and treated, full-blown type 2 diabetes will develop. This is an irreversible condition in which the pancreas is no longer able to produce enough insulin, insulin resistance worsens and sugar levels rise to dangerous levels.


If one skips a meal, or fasts, or even while one is sleeping, the blood sugar level drops. The brain is very intolerant of a low blood sugar level, as it needs a constant supply for all its neuro-processes. The brain then signals the liver to release sugar from its stores of glycogen. This will happen after 5 hours in all individuals (Met A and B) if no food is ingested. An amount of between 40 and 60 mg of sugar is released into the blood stream, which will trigger release of insulin from the pancreas, which will follow the metabolic pathways of Met A or Met B as described above. This is important to appreciate, as it explains why a person with Met B, can continue to gain weight while asleep or skipping meals!


  • Fatigue
  • Mild depression
  • Carb cravings and binges
  • Brain fog
  • Inability to focus and concentrate
  • Midline fat (apple shape)
  • Easy weight gain and difficult weight loss
  • Restless sleep
  • Decreased libido
  • Blurry vision


Blood tests include testing fasting blood glucose; fasting total cholesterol; TSH; fasting HbA1C and vitamin D3.

Often blood tests which are slightly out of range are ignored as being insignificant. Be alerted especially to glucose and HbA1C, which may be lower than expected, as these are early warning signs of Met B.

Fortunately, if Met B is recognised early, treatment and reversal of this condition is easily possible without needing to resort to medications.


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Metabolism A or B – Which are You? Part 1

Dr David Nye
About The Author
- MB CHB (UCT), MFHOM (UK), DIP HOM (CEDH). He practises integrative medicine together with his wife, Dr Sandi Nye, in Pinelands Cape Town. As a registered medical doctor, homeopath and acupuncturist, he has a special interest in chronic illness, especially when conventional medicine fails to help. He uses a variety of modalities, tests and treatments in his quest to find the best solutions for each patient.