GI and BMI; Do They Mean Anything?

GI (Glycemic Index) and BMI (Body Mass Index) are Questioned Here!

Let me start with BMI since it is simpler. BMI is the ratio of your weight relative to a variety of measures of your height, age, and sex. It is supposed to reflect your health in terms of how “fit and thin” you are relative to your height given your height, weight, sex and age. But does it have any meaning?

Let me show you why it has no meaning and should not ever be used to calculate fitness and/or health.

Example: take 2 men. Both 6 feet tall and both 35 years old. One sits at the computer all day and is fat (fat weighs less than muscle) and so his BMI is 30. The other man also same age and height and is a workout fanatic. He lifts weights, boxes, etc. His BMI is 36 (this by the way was Arnold Schwarzenegger’s BMI when he won top awards for his body).  If we look at the BMI, the guy sitting by his computer all day eating, wearing size 20 clothes is fitter (as per BMI!) than the guy working out all day.

This is not only clueless but also crazy.

Consider also ethnic differences

Place a small framed Asian person next to a large framed Northern European of the same height, age, and sex and tell me if you believe they should have the same weight and thus BMI. No they do not. If they did, one would be either very unhealthy and skinny or the other very unhealthy and fat. BMI is a lovely idea but because it looks at mass of the body, meaning density of the body, the denser something is, the heavier it is. The BMI equation seems to forget this little law of physics. Thus BMI is pretty much out the window in terms of evaluating your health.

How do you evaluate your health? Take a look at the size of clothing you are wearing relative to your height and age and look at how much energy you have. This should tell you all. Do not attempt to be wearing a size 0f clothing if you are meant to be a size 12 in terms of your ethnicity! There is a reason why Northern Europeans are bigger, why people in Africa are also bigger and why people in Asia are smaller! This is not a “fault” but is a necessary adaptation to their environment. The fact that you may find them live in places with BMI standards for the region they reside does not mean their BMI is wrong!!

Now let’s look at GI

According to Wikipedia, the following is how it is defined:

Glycemic load accounts for how much carbohydrate is in the food and how much each gram of carbohydrate in the food raises blood glucose levels. Glycemic load is based on the glycemic index (GI), and is defined as the grams of available carbohydrate in the food times the food’s GI.

Glycemic Index or GI is a calculation based on the amount of insulin released in the blood as a result of eating food high in carbohydrate, which is a measure of glycemic load. This assumes that releasing insulin is a bad thing and so eating sugar substitutes or sand is better for us since the GI of those is zero. I think you already see the irony is but let me explain a point that is missed very seriously in terms of carbohydrates.

Assume you are eating a very high GI food, say rice. Its GI will be very high since it is pure carbs. Yet the rise in insulin has little significance. Why? Because insulin’s job is to convert the rice into fat and in the process it gets used up. There will be no insulin left in the blood looking for carbs to convert to fat since it just did it all. Thus eating high carbs diet (as Asians do for example who eat their traditional food) do not cause diabetes 2–their Westernized lifestyle as a result of eating sugar changed all that! Prior to Western food’s arrival to the Asian countries, diabetes 2 was of no concern to Asians.

Thus high GI foods are not the problem. Let’s look at low GI foods: sugar substitutes. Sugar substitutes are either low GI (Stevia for example) or no GI (aspartame). Assume you take a spoonful of sugar substitutes (SS). What happens? Insulin does not release. If insulin does not release, the SS has no sucrose or glucose and so it will not be placed into storage as fat for later consumption as glucose by the brain or muscles. Brain and muscles live on glucose for energy. So when they reach out to the hormone called leptin to fetch some glucose for energy, there is none.

Not having any energy for the brain signals famine. Famine signals you to eat more. So you are always binging on foods and drinks all without carbs that could be converted to fat but all with SS, which provides no glucose as energy. Thus the more you eat, the more your brain senses famine and the more it slows your metabolism. The slower your metabolism, the fatter your will become and the less active you will also become since during famine the brain stops you from running for fun 4 miles! Your brain is the command center and it will place you on the couch watching TV or napping all day. This is what is happening to our kids!

So given that low GI foods actually make you fat, what happens if you eat high GI foods? Grab a medium size apple for instance.  The GI is 52, carbohydrate is 13% and GL is 78. Thus according to this you are better off eating a spoon full of aspartame than that apple. But part of that apple is insoluble fiber, the skin, and though it is not sugar, will not become sugar, and will not spike your insulin, it is counted into the GI! Insoluble fiber should reduce the GI calculated of that apple because much of it is heading down to your gut undigested to feed the good bacteria in your gut. The calculation of the GI does not account for the insoluble fiber, which is a very important element in reducing GI in our carbs filled food!

Now consider tomato juice! It has no fiber, only fruit (tomato is a fruit) without skin and seeds juiced into tomato juice. Its GI is 27. Thus in your mind, having a glass of tomato juice is better than the apple because its GI is lower than eating an apple. But since GI does not account for the fructose that is going to be taken out of that apple and ends up in the gut as bacteria food and not our food, the amount of insulin released by the apple may actually be less than for the tomato juice. That is because in the juice of the tomato all carbs activate insulin whereas in the apple only the part not attached to the fiber will! It is not measured how much of that apple remains as carbs to spike your insulin relative to tomato juice–that is the number we should watch!

The problem with GI is that it assumes that all sugars activate insulin equally, which is not true. Fructose does not activate insulin at all. Fructose ends up in the liver and becomes ethanol. Ethanol will never ever be sugar; it is alcohol. So in eating a tablespoon of sugar, only about half of that will activate insulin and thus its true GI level is less than what is provided; it is assumed that sugar is sugar and thus activates insulin the same way. Only sucrose and glucose content of carbs (starch as well) will activate insulin; fructose does not. Sugar substitutes, on the other hand, may have plenty of carbs in them that have no sweetness but can spike your insulin. Artificial sweeteners do spike you insulin and affect your metabolism for the worse. Why? Here is a direct quote from the above linked article:

…it should be noted that artificial sweeteners don’t necessarily help limit calorie intake. A previous study by scientists in the US suggested that consuming artificial sweeteners could make people put on weight because experiments on laboratory rats showed that those eating food sweetened with artificial sweeteners ate more calories than their counterparts whose food was sweetened with normal sugar.


Forget about counting your GI and BMI. Instead, eat healthy foods, low in sugar but high enough in carbs so that the body can make glucose for the brain and muscles to use and to get the insulin working right and be able to get out of your blood! Eat foods without sugar and without artificial sweeteners.

Sugar craving means your brain craves energy. The brain is very capable of making energy from fat and so there is no need to eat sugar or sugar substitutes. If you eat it, it is because you want it and not because you need it! An alternate source of energy is hydration. Hydrating with electrolyte like substances (water with salt and flavoring without sugar) as described in the book Fighting the Migraine Epidemic can replace your sugar cravings and perk you up full of energy while losing fat since your brain and muscles are using fat that they convert as their glucose for energy!

And that is how it is and how it should be!

Comments are welcome!


About Angela A Stanton, Ph.D.

Angela A Stanton, PhD, is a Neuroeconomist focusing on chronic pain--migraine in particular--physiology, electrolyte homeostasis, nutrition, and genetics. She lives in Southern California. Her current research is focused on migraine cause, prevention, and treatment without the use of medicine. As a forever migraineur from childhood, her discovery was helped by experimenting on herself. She found the cause of migraine to be at the ionic level, associated with disruption of the electrolyte homeostasis, resulting from genetic variations of all voltage dependent channels, gates, and pumps (chanelopathy) that modulate electrolyte mineral density and voltage in the brain. In addition, insulin and glucose transporters, and several other variants, such as MTHFR variants of B vitamin methylation process and many others are different in the case of a migraineur from the general population. Migraineurs are glucose sensitive (carbohydrate intolerant) and should avoid eating carbs as much as possible. She is working on her hypothesis that migraine is a metabolic disease. As a result of the success of the first edition of her book and her helping over 5000 migraineurs successfully prevent their migraines world wide, all ages and both genders, and all types of migraines, she published the 2nd (extended) edition of her migraine book "Fighting The Migraine Epidemic: Complete Guide: How To Treat & Prevent Migraines Without Medications". The 2nd edition is the “holy grail” of migraine cause, development, and prevention, incorporating all there is to know. It includes a long section for medical and research professionals. The book is full of academic citations (over 800) to authenticate the statements she makes to make it easy to follow up by those interested and to spark further research interest. It is a "Complete Guide", published on September 29, 2017. Dr. Stanton received her BSc at UCLA in Mathematics, MBA at UCR, MS in Management Science and Engineering at Stanford University, PhD in Economics with dissertation in neuroscience (culminating in Neuroeconomics) at Claremont Graduate University, fMRI certification at Harvard University Medical School at the Martinos Center for Neuroimaging for experimenting with neurotransmitters on human volunteers, certification in LCHF/ketogenic diet from NN (Nutrition Network), certification in physiology (UPEN via Coursea), Nutrition (Harvard Shool of Public Health) and functional medicine studies. Dr. Stanton is an avid sports fan, currently power weight lifting and kickboxing. For relaxation (yeah.. about a half minute each day), she paints and photographs and loves to spend time with her family of husband of 45 years, 2 sons and their wives, and 2 granddaughters. Follow her on Twitter at: @MigraineBook, LinkedIn at and facebook at
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4 Responses to GI and BMI; Do They Mean Anything?

  1. Roald Michel says:

    Yes….of course……no doubt about it…..but…….er…….ugh…..sure, there’s no other way.

    Liked by 1 person

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