High Protein Diets and Early Weight Loss: It isn’t Good

Low Carb Diet Myth: by Terry Simpson MD – YourDoctorsOrders.com from Producergirl Productions on Vimeo.

Going on a low carb diet means a rapid weight loss.  This provides incentive to continue with a diet while eating foods that many love: steak, eggs, bacon, and cheese. But you’re not losing fat,  you’re losing glycogen and water, and that worries us doctors.


As appealing as high protein diets sound: eat as much of this as you want- protein alone is counterproductive as a basis of a diet plan

Glycogen is carbohydrate your body builds to store energy. Unlike fat, there is no downside to having glycogen, in fact, glycogen is essential to life.

In low carb diets the body’s glycogen is used up quickly, and it can’t build glycogen without  carbohydrates from your diet. For every pound of glycogen your body uses you also lose  two pounds of water – that’s the rapid weight loss.  

In the liver glycogen maintains your blood sugar level- and the sugar, glucose,  is used by your body as energy for every single cell. Maintaining a level of sugar is essential to  function. Without it your brain can’t think, and you go into a coma.  As glucose levels fall in the blood stream the liver serves as a reservoir of stored glucose and maintains the level of glucose by cleaving the glycogen molecules into glucose. In the average liver ten percent of the weight of the liver is in glycogen, in some people this number is higher. Unlike fat, glycogen is not detrimental to the liver. Fatty liver disease is the most common cause of liver failure, but people can have large stores of glycogen without consequence.

In muscles, glycogen is what provides the muscles energy to work- not just those powerful biceps, but your heart. If your heart runs out of glycogen you will have a heart attack. Muscles contraction causes energy expenditure and that comes from glycogen that is stored in the muscle. As the muscles contract glycogen is is cleaved into glucose molecules that make ATP which is the source of energy for muscle use. Athletes take advantage of this knowledge before competitions by working to “carb-load” or increase glycogen in muscles, particularly for marathons or endurance contests.  In prolonged exercise the glycogen storage may decrease by as much as 75%.  In stress, or the “fight or flight” response, epinephrine is released which enhances the bodies ability to utilize muscle glycogen – this allows us the energy to quickly flee.

The notion that when carbs are not available your body uses  fat  is wrong! Without glycogen your body cannot use  fat as energy!

In a non-fasting state, you can use glucose, in a fasting state glucose level is maintained by glycogen stores in the liver.

In order to replenish glycogen one needs a source of carbohydrates in your diet. Not candy bars, or processed foods but fruits and vegetables. 

Here is the biochemistry: Glucose is metabolized during glycolysis, a process resulting in the production of pyruvic acid. If an adequate amount of oxygen is present, pyruvic acid is used in the Kreb’s Cycle to generate a large amount of ATP. The first step in this process is to transfer pyruvic acid into the mitochondrion and remove a carbon dioxide. The process removes a couple of hydrogen atoms, and adds a Co-enzyme A, forming acetyl Co-A. The two carbon acetate moiety is then tacked on to an oxaloacetic acid to make citric acid, the first step in the Kreb’s or Citric Acid Cycle. When lipids are used, enzymes allow them to enter the cycle as acetyl Co-A, as well as in a process known as Beta-oxidation. In order to keep this sequence continuing, adequate amounts of oxaloacetic acid must be present. The source of oxaloacetic acid in this case is pyruvic acid. However, pyruvic acid is obtained from the metabolism of glucose. Without glucose, there will is not enough pyruvic acid and oxaloacetic acid levels are low. Ultimately lipids can not be used in the Kreb’s Cycle. The use of  lipids as a primary energy source creates an environment in which the body cannot utilize lipids as an energy source.

Since muscle cells cannot utilize lipids for energy, free fatty acids begin to accumulate in the intercellular fluid and move into the blood stream. Upon reaching the liver, free fatty acids are converted into ketone bodies. Some ketone bodies are excreted in the urine. This is ketosis, which many high protein diets say is the key to “fat burning.” Ketones can be used for fuel, but not effectively.  As ketone bodies accumulate in the blood (ketosis) and change the pH of the blood causing it to become more acidic, in extreme cases this can lead to acidosis.  This is the typical post-protein diet that  results are tiredness and nausea – or the feeling that you are drunk.

Depletion of glycogen stores means no reserve should people become ill. Glycogen depletion  can even lead to sudden cardiac death.

That high protein diets eschew the use of junk foods as an energy source and preach against that is the best part of these diets (Zone, Atkins, Southbeach, Paleo). The bad part is the false science that high protein diets lead to weight loss, and the more often people go onto these diets the less weight they see lost – the reason, they have gained more fat mass, and the loss of glycogen stores contribute to less and less weight loss each time they attempt these diets.

People who persist in high protein diets for long periods of time have incorporated vegetables into their diet as a source of carbohydrates. They remain fit and strong because they have avoided the junk food of modern life. But those who fail to incorporate enough fruits, vegetables, or starches will have quick weight loss, but not permanent weight loss.

If you go on any diet, be sure to include plenty of fruits,  vegetables and starches.

Contrary to what low carber’s preach, there is nothing wrong with fruits, vegetables, or starches.

Starch from plants is a great source of carbohydrates for the human body

Dr. Terry Simpson About Dr. Terry Simpson
Dr. Terry Simpson received his undergraduate and graduate degrees from the University of Chicago where he spent several years in the Kovler Viral Oncology laboratories doing genetic engineering. He found he liked people more than petri dishes, and went to medical school. Dr. Simpson, a weight loss surgeon is an advocate of culinary medicine. The first surgeon to become certified in Culinary Medicine, he believes teaching people to improve their health through their food and in their kitchen. On the other side of the world, he has been a leading advocate of changing health care to make it more "relationship based," and his efforts awarded his team the Malcolm Baldrige award for healthcare in 2011 for the NUKA system of care in Alaska and in 2013 Dr Simpson won the National Indian Health Board Area Impact Award. A frequent contributor to media outlets discussing health related topics and advances in medicine, he is also a proud dad, husband, author, cook, and surgeon “in that order.” For media inquiries, please visit www.terrysimpson.com.

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Latest Comments

  1. Leisureguy says:

    I have kept careful track of my food intake on the LCHF diet I’m following, and it is certainly NOT a high-protein diet. The recommended daily intake of protein is to get 10%-35% of calories from protein. Here is my average percentage of calories from protein over the past 3 weeks: 31%, 25%, 29%. That falls well within the recommended range. I do not see that this would be considered a “high-protein” diet, which seems to be more the body-builder’s diet that includes protein shakes, protein powders, and protein supplements. My own intake is exactly in line with recommendations.

    My carb intake is lower: based on 4 calories/gram of net carbs (carb grams – fiber grams), I get 5%, 4%, and 6% for those same three weeks. So it’s certainly a low-carb diet, but if I understand your article, the problems you describe come from a high-protein diet, and this diet does not qualify. It has a recommended level of protein.

  2. Dr. Terry Simpson says:

    Sounds terribly complex and unneeded. For diets we have some simple rules: You should have as many fruits, vegetables, and starches as you want. If you want protein- use mainly fish, but nor more than 3 grams cooked at a time. That way you won’t get into any trouble. If it has a package and a label, it probably isn’t something you want to eat.

  3. Terry Simpson says:

    Diets seem to be unnecessarily complex. Immediate blood sugar spikes are not harmful it is the long-term spikes we care about. Far from a simple starch, potatoes are rather complex. It isn’t the high protein that is the issue- it is the low carbohydrates that cause the glycogen issues.

  4. Terry Simpson MD says:

    Sadly he misses the one component – and devil in details. The conversion depends on pathways that have been speculated but no enzymes in humans to catalyze those pathways. Lovely thing about science- you can speculate, but you have to prove it. Alas, that pathway has never been proven.

    Still – interesting speculation. Remember we need a net increase in glucose in order to thrive- and the question is how to increase glucose not to have a net even. So the idea that fatty acids do not go into making glucose was first looked at years ago- and mammals do not have that shunt in their pathway that is typically found in other creatures.

    Clearly, however, there is a method to provide energy from fats – but it does require glucose. Not nearly as much as in the modern diet. The question is of more interest in Alaska Natives (my people) who have higher levels of fat in their diet and a deficiency of CPT-1 (what is now called the arctic variant). The question is, do all individuals have that – or is it in some: that is, do people of the North have it but it is only present in them (like the Arctic variant) or is it universal. Another example – lactose, not all people have the ability to convert and use that sugar.

    Rather the point of the article was to make people aware of glycogen and its role, and to make people aware that early weight loss is glycogen related, not from fat loss. Few people have total carbohydrate free diets- but there are always those who hate vegetables enough that if they go on such diets will cause themselves harm. Sudden cardiac death from individuals newly on “low carb” diets is concerning.

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