Also see:
Sucrose substitution in prevention and reversal of the fall in metabolic rate accompanying hypocaloric diets
Sugar and body weight regulation.
rethink how you exercise: An interview with Rob Turner – Part 1
rethink how you exercise: An interview with Rob Turner – Part 2
Low carb + intensive training = fall in testosterone levels
The Dangers of Fat Metabolism and PUFA: Why You Don’t Want to be a Fat Burner
Stress — A Shifting of Resources
Ray Peat, PhD on Low Blood Sugar & Stress Reaction
Blood Sugar – Resistance to Allergy and Shock
Low Blood Sugar Basics
Temperature and Pulse Basics & Monthly Log
Ray Peat, PhD on Thyroid, Temperature, Pulse, and TSH
Body Temperature, Metabolism, and Obesity
Thyroid, Temperature, Pulse
Sugar (Sucrose) Restrains the Stress Response
Belly Fat, Cortisol, and Stress
PUFA Decrease Cellular Energy Production
PUFA Promote Stress Response; Saturated Fats Suppress Stress Response
Saturated and Monousaturated Fatty Acids Selectively Retained by Fat Cells
Free Fatty Acids Suppress Cellular Respiration
The Randle Cycle
Low-carbohydrate diets and all-cause mortality: a systematic review and meta-analysis of observational studies
“…remember that prolonged dieting (Atkins, low-fat, low-calorie, or a combination) tends to shut down thyroid function. This is usually not a problem with the thyroid gland (therefore blood tests are likely to be normal) but with the liver, which fails to convert T4 into the more active thyroid principle, T3. The diagnosis is made on clinical ground with the presence of fatigue, sluggishness, dry skin, coarse or falling hair, an elevation in cholesterol, or a low body temperature. I ask my patients to take four temperature readings daily before the three meals and near bedtime. If the average of all these temperatures, taken for at least three days, is below 97.8 degrees F (36.5 C), that is usually low enough to point to this form of thyroid problem; lower readings than that are even more convincing. It may be appropriate for those of you who fit these criteria to be prescribed thyroid by your doctor, and if so, a natural form of the hormone, which contains T3, is far superior to the most popular form of prescription thyroid, synthetic T4.” -Dr. Robert Atkins
“Stress and starvation lead to a relative reliance on the fats stored in the tissues, and the mobilization of these as circulating free fatty acids contributes to a slowing of metabolism and a shift away from the use of glucose for energy. This is adaptive in the short term, since relatively little glucose is stored in the tissues (as glycogen), and the proteins making up the body would be rapidly consumed for energy, if it were not for the reduced energy demands resulting from the effects of the free fatty acids.” -Ray Peat, PhD
“I don’t have an eating plan, other than to be perceptive and to learn about your physiology, so that you can adjust things to your needs. Any craving is a good starting point, because we have several biological mechanisms for correcting specific nutritional deficiencies. When something is interfering with your ability to use sugar, you crave it because if you don’t eat it you will waste protein to make it.” -Ray Peat, PhD
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“Low carb” is a nutritional buzz word and talks about avoiding sugar because “it’s the devil” are commonly echoed ad nauseam among both lay persons and health professionals. But does this approach having any sound backing to it when it comes to supporting health and metabolism?
Carbohydrate’s function
Stable and efficient cells have a constant supply of glucose, their preferred fuel source. We get glucose from dietary carbohydrate. Carbohydrates allows cells to produce carbon dioxide and ATP (adenosine triphosphate) via oxidative metabolism or cellular respiration. ATP is a currency of energy that is spent in order to make chemical reactions occur. Without ample energy, optimal function and structure of cells cannot be maintained. If the diet isn’t supplying adequate glucose, the body will convert its own tissues to glucose (gluconeogenesis) to supply this vital fuel if stored sugar in the form of glycogen isn’t available.
Why go low carb?
Most people’s motivation for low carbohydrate eating stems from the desire to lose stored fat. When dietary carbohydrate intake is restricted and blood sugar becomes low, the body becomes stressed and will turn to backup fuel sources to get cells energy using two primary processes. One such mechanism is called lipolysis in which the adrenal hormone adrenaline (and other lipolytic stress mediators) signals the liberation of fatty acids from stored fat to be used for energy. This means that you will indeed use stored fat for energy, resulting in fat loss.
The other mechanism that works in conjunction with lipolysis is called gluconeogenesis. During this inefficient process, another adrenal hormone, cortisol, attempts to raise blood sugar and flight inflammation by converting the body’s own tissues (thymus, liver, muscle, skin, etc) to make glucose to fuel cells. This conversion occurs in the liver. A seemingly good sign, a loss of scale weight, can occur as a result of the loss of protein containing tissue, like muscle.
Long-term effects of a low carb lifestyle
Low carb dieting appears to be a good strategy to spur fat loss and lower scale weight in the short term. However, the plan’s short-term fat loss comes at the expense of suppressing the resting metabolism long term, destroying our own tissues, depleting glycogen, burdening the liver, and stressing every cell in the body. The effects of chronically high adrenaline and cortisol used to support both lipolysis and gluconeogenesis are widespread.
When fatty acids are liberated during lipolysis, these fats tend to be rich in polyunsaturated fatty acids (PUFA) which promote the stress response and suppress the action of the thyroid, the gland which regulates metabolism, at multiple sites. Exposure to PUFA leads to a metabolism that is not running on all cylinders. PUFA also drags water into cells creating a “puffy” appearance that we commonly see among Americans both young and old.
Gluconeogenesis, which breaks down the body’s protein containing tissues to create glucose in the liver, is spurned by the hormone cortisol. If the protein containing tissues used to faciliate this process are rich in the amino acids cysteine or tryptophan, these amino acids suppress thyroid function.
The tryptophan is likely to be made into serotonin, especially in an alarm state. Serotonin lowers metabolic efficiency, liberates free fatty acids, increases cortisol & other stress mediators, promoting a continued alarm state, edema, & inflammation. The body appears to intentionally slow the metabolic rate during chronic stress so it doesn’t quickly run out of tissues to use as fuel in this emergency state.
High cortisol also depresses immune function, decreases glucose oxidation, affects bone health, raises serotonin, contributes to belly fat, and thins the skin.
Being fight or flight hormones, both cortisol and adrenaline send oxygen and nutrients to the extremities to prepare for an emergency situation. When chronically high due to low carbohydrate intake and low blood sugar, these hormones shut down digestive processes as the gut doesn’t receive the nutrients and oxygen it needs to digest, assimilate, and eliminate foods resulting in micro and macronutrient deficiencies and digestive troubles (constipation, bloating, gas, loose stool, etc). The resulting low thyroid function also severely hinders digestive function, leading to malabsorption of food and intestinal bacterial overgrowth.
Emergency hormones no longer
Adrenaline and cortisol have morphed from adaptive, use as needed hormones into ones that are being used around the clock to provide cells with energy. The greater a role that these emergency hormones play in our daily function, the quicker the body is breaking down, the faster we age, and the more thyroid suppression we have over time.
When stress mediators like adrenaline and cortisol are low, the body’s ability to create protective, anti-aging hormones such as DHEA, T3, progesterone, and pregnenolone is improved. Detoxification, digestion, and the immune system are more likely to function optimally as well. The temptation to lose fat quickly by limiting carbohydrate intake is a slippery slope in the long run due to the tissue wasting, accelerated aging, and metabolism suppression that occurs with a low carb strategy.
A different approach
The irony of the low carb approach is that the very thing such eaters are trying to avoid actually supports thyroid (metabolic) function and their long-term success. The right sugars (fruit juice, ripe fruits, milk sugars) lower adrenaline and cortisol, feed cells the glucose they need, are easy on the gut, spare our protein containing tissues, and support the production of the active thyroid hormone (T3).
Cells need a constant supply of glucose so your nutrition program should have blood sugar regulation as priority numero uno. Blood sugar and macronutrient balance is the name of the game as is choosing foods that we are designed to digest and that support the thyroid. Carbohydrate (push blood sugar up) and protein (pulls blood sugar down) work synergistically to maintain blood sugar while fats help slow the entrance of protein and carbohdyrate into the bloodstream. This is why fat, protein, and carbohydrate consumption should be balanced within each meal to provide long lasting, stable energy (glucose) to cells. There also needs to be an emphasis on the right sources of protein, fat, and carbohydrate as all sources are not created equal.
Some carbohydrates are very hard for us to digest (green vegetables) while others (grains, legumes, starchy veggies) will raise blood sugar so quickly that they will cause blood sugar regulation issues leading to the perpetuation of the affects of high cortisol and adrenaline. Undigested food matter from starches and green plants becomes food for bacteria in the intestines creating an environment not suitable for optimal intestinal health.
Glycine, an amino acid found in abundance in bone broth/gelatin, inhibits lipolysis. Saturated fats are protective to our physiology whereby an abundance of PUFA in the diet produce inflammation, low thyroid, lipid peroxides and free radicals, and degeneration on a wide scale.
A low carbohydrate diet is the enemy of those looking for long-term weight management success and optimal health. The reduction in scale weight and stress-induced fat loss is what pulls people into the methodology, but I encourage those currently using or considering using the method to consider the big picture. The blow back from the approach can take months or years to unwind, especially if combined with illogical exercise methodologies.
FPS coaches a 12 week nutrition course based solely on the methodology of Ray Peat, PhD. Please click here for more information.
Resources
Gelatin, stress, longevity by Ray Peat, PhD
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Low Carb, Sucrose, and Metabolism:
Am J Med. 1986 Aug;81(2):280-4.
Sucrose substitution in prevention and reversal of the fall in metabolic rate accompanying hypocaloric diets.
Hendler RG, Walesky M, Sherwin RS.
Hypocaloric diets cause a fall in resting metabolic rate that interferes with weight loss. To evaluate the mechanisms underlying this phenomenon, resting metabolic rate was measured sequentially in six healthy obese women on a weight maintenance diet (more than 2,300 kilocalories), after 15 days of an 800 kilocalories carbohydrate-free diet, and after isocaloric sucrose replacement for an additional 15 days. The carbohydrate-free diet produced a 21 percent decline in resting metabolic rate (p less than 0.005) as well as a decrease in circulating triiodothyronine (41 percent, p less than 0.02) and insulin (38 percent, p less than 0.005) concentrations. Plasma norepinephrine levels also tended to decline (10 percent, 0.05 greater than p less than 0.1). However, when sucrose was substituted, resting metabolic rate rose toward baseline values even though total caloric intake was unchanged and weight loss continued. The sucrose-induced rise in resting metabolic rate was accompanied by a rise in serum triiodothyronine values, but not plasma insulin or norepinephrine concentrations. Throughout, changes in resting metabolic rate correlated with changes in serum triiodothyronine levels (r = 0.701, p less than 0.01). In four obese women, a hypocaloric sucrose diet was given at the outset for 15 days. The fall in both resting metabolic rate and triiodothyronine concentration was markedly reduced as compared with values during the carbohydrate-free diet. It is concluded that carbohydrate restriction plays an important role in mediating the fall in resting metabolic rate during hypocaloric feeding. This effect may, at least in part, be related to changes in circulating triiodothyronine levels. Incorporation of carbohydrate in diet regimens may, therefore, minimize the thermic adaptation to weight loss.
I have been eating this way for nearly 10 years. I have a friend who as done it for 12 years. It is a healthy and sustainable way of life and I don’t understand quite why you think otherwise. Glucogenesis is the liver’s way of manufacturing glucose, it doesn’t need an ounce of muscle or organ tissue from the body as long as protein is consumed in the diet. The body only needs enough glucose to equal a teaspoon of sugar. A good healthy low carb diet can easily handle this requirement. I do have regular checkups and I continue to be healthy.
Thanks for your comment, Mary.
A healthy body needs more than 4g (16 calories) or a teaspoon of sugar. The protein you consume shouldn’t be used to feed stress-related processes, but rather for the repair and growth of the skeleton as a whole and to fuel vital detoxification processes. The body will use protein largely from the thymus gland and skeletal muscle to make glucose in the liver; but this is an emergency, as needed system built into the body to be used during times of low blood sugar. There are more efficient and healthier means by which to provide glucose to cells.
Using protein from an immune-regulating gland and the musculature of the body doesn’t appear to be a health promoting practice. Why not just get the right sugars from the diet? It’s clear that the body needs glucose, or it wouldn’t go to such means to get sugar to cells. Balancing blood sugar should be at the center of any nutrition strategy because without that balance the body will be in a perpetual stress response in the effort to provide cells supplemental fuel that could’ve been had from the diet.
The absence of symptoms is not a state of health. The first sign of heart disease for some individuals is a heart attack and subsequent death. But ultimately, the ability to overcome stressors depends upon the body’s ability to create energy under the direction of the thyroid. The resulting stress promoting substances and hypoglycemia induced by low carb eating are anti-thyroid and thus do not provide the means by which the body can overcome stress.
I love the authoritative way you write this as if it had any basis in fact.
Don’t let your education get in the way of your learning.
Just saw Feinman’s comment now 🙂
🙂
Awesome article. The longer a person’s mind has been domesticated by schooling, the more narrow their ability to grasp anything about the body not funded by a pharmaceutical company.
I am curious where Mary Titus gets the understanding that the body needs only a teaspoon of sugar? Mary have you taken your temperature and pulse? I have never met anyone who has been on a True high protein-low carb diet for any significant amount of time, that is warm, eats adequate calories and has good digestion…
Thank you so much for this article – I wish I had found it sooner! After sticking to a low-carb diet for over a year now, under the understanding that it could help with some serious health problems, I’ve taken a step back and realised that paleo sucks! I am constantly cold, I still struggle with my weight despite working-out 5-6 times per week and eating less and less, my health problems are actually slightly worse than they were, and I’m desperate to get my health back! If I go back to eating proper, wholegrain carbs now, can I reverse the damage I’ve already done? I’d really appreciate some guidance on how to fix this.
Your symptoms are typical of what occurs with carbohydrate restriction.
I would start with slowly introducing ripe, sweet-tasting fruits back into your diet followed by milk if you’ve been influence by the “Paleo” crowd and were avoiding dairy. There are several other factors to consider, but I would need more context to offer personalized advice. Thanks for reading and be patient yet consistent with correcting your health issues.
The following blogs should help supplement the information that’s in this article:
Low Blood Sugar Basics
http://www.functionalps.com/blog/2012/11/16/low-blood-sugar-basics/
Stress — A Shifting of Resources
http://www.functionalps.com/blog/2014/05/25/stress-a-shifting-of-resources/
Ray Peat, PhD on Low Blood Sugar & Stress Reaction
http://www.functionalps.com/blog/2012/11/26/ray-peat-phd-on-low-blood-sugar-stress-reaction/
Temperature and Pulse Basics & Monthly Log
http://www.functionalps.com/blog/2012/11/19/temperature-and-pulse-basics-monthly-log/
I should also mention that I eat grass fed meat and whole fat dairy and that I try to eat only organic fruits and vegetables as much as possible.
I am trying to understand this better. If you are going to loose bodily fat (regardless of the diet choice) you will have to release fatty acids and oxidize it. Therefore your system will have to cope with the stored PUFA’s regardless of how you came to release it, not so?
Can you refer me to any research supporting the reasoning that cortisol may upregulate serotonin to the point of the adverse effects explained? I can’t seem to find any.
Interesting though, carbohydrate intake allow for tryptophan (pre-cursor to serotonin) to cross the the blood brain barrier for uptake … and I quote:
‘Protein-rich foods, such as meat or chicken, contain high levels of tryptophans. Tryptophan appears in dairy foods, nuts, and fowl. Ironically, however, levels of both tryptophan and serotonin drop after eating a meal packed with protein. Why? According to nutritionist Elizabeth Somer, when you eat a high-protein meal, you “flood the blood with both tryptophan and its competing amino acids,” all fighting for entry into the brain. That means only a small amount of tryptophan gets through — and serotonin levels don’t rise.
But eat a carbohydrate-rich meal, and your body triggers a release of insulin. This, Somer says, causes any amino acids in the blood to be absorbed into the body — but not the brain. Except for, you guessed it — tryptophan! It remains in the bloodstream at high levels following a carbohydrate meal, which means it can freely enter the brain and cause serotonin levels to rise, she says.’
———–Thanks for your comment.
I am trying to understand this better. If you are going to loose bodily fat (regardless of the diet choice) you will have to release fatty acids and oxidize it. Therefore your system will have to cope with the stored PUFA’s regardless of how you came to release it, not so?
———–The difference lies in how the lipolytic activity happens – during rest and organism stability with low energy demand or during organism instability and high energy demand (i.e. stress). Low carbohydrate diets promote the second option.
Can you refer me to any research supporting the reasoning that cortisol may upregulate serotonin to the point of the adverse effects explained? I can’t seem to find any.
————Connect the dots using these blogs.
Serotonin, Fatigue, Training, and Performance
http://www.functionalps.com/blog/2012/02/15/tryptophan-fatigue-training-and-performance/
Carbohydrate Lowers Serotonin from Exercise
http://www.functionalps.com/blog/2012/02/15/carbohydrate-lowers-free-tryptophan/
Sugar (Sucrose) Restrains the Stress Response
http://www.functionalps.com/blog/2011/02/04/sugar-sucrose-restrains-the-stress-hormone-system/
Interesting though, carbohydrate intake allow for tryptophan (pre-cursor to serotonin) to cross the the blood brain barrier for uptake … and I quote:
‘Protein-rich foods, such as meat or chicken, contain high levels of tryptophans. Tryptophan appears in dairy foods, nuts, and fowl. Ironically, however, levels of both tryptophan and serotonin drop after eating a meal packed with protein. Why? According to nutritionist Elizabeth Somer, when you eat a high-protein meal, you “flood the blood with both tryptophan and its competing amino acids,” all fighting for entry into the brain. That means only a small amount of tryptophan gets through — and serotonin levels don’t rise.
But eat a carbohydrate-rich meal, and your body triggers a release of insulin. This, Somer says, causes any amino acids in the blood to be absorbed into the body — but not the brain. Except for, you guessed it — tryptophan! It remains in the bloodstream at high levels following a carbohydrate meal, which means it can freely enter the brain and cause serotonin levels to rise, she says.’
—————This blog provides evidence to the contrary.
Carbohydrate Lowers Serotonin from Exercise
http://www.functionalps.com/blog/2012/02/15/carbohydrate-lowers-free-tryptophan/
What reference(s) accompanies this quote and how does it integrate into anything meaningful?
I wish I could comment on comments, this is very late considering Becs comment was made in may, (I agree with everything this article says) but nothing about paleo says to restrict your carb intake, with a paleo diet your main source of macronutrients is suppose to be from carbs!
Love your articles and hatchling for the clarifications on Peat’s work.
The difference lies in how the lipolytic activity happens – during rest and organism stability with low energy demand or during organism instability and high energy demand (i.e. stress). Low carbohydrate diets promote the second option.
Can you explain why PUFAS released during rest and organism stability are handled better. Do they not still exert the ills that you talk about. This would be very helpful to understand.
Yes, your understanding is my understanding about lipolysis in rest v. distress. Muscle, a metabolically active tissue, at rest and during sleep consumes stored fat. The higher the metabolic rate, the more quickly the stored fat is consumed. I suspect there still are negative ramifications on cells from exposure to the PUFA, but without the hormonal, inflammatory, and energy-suppressing effects that occurs under duress.
“Since fat has a very low rate of metabolism, people who lose muscle by fasting are going to have increasing difficulty in losing weight, since they will have less active tissue to consume fat. Building up muscle and lymph tissue for optimal health – even if it initially causes a slight weight gain – will make reducing easier by increasing mass of metabolically active tissue.”
“Many dietitians claim that exercise doesn’t increase the need for protein, but the Russians have found that a combination of exercise and increased protein intake can increase the muscle mass. In a woman, this process can not only improve grace and body proportions, but it also increases the body’s ability to burn up fat.”
“In the resting state, muscles consume mainly fats, so maintaining relatively large muscles is important for preventing the accumulation of fats.”
Ray Peat, PhD: Quotes Relating to Exercise
http://www.functionalps.com/blog/2012/02/01/ray-peat-phd-quotes-relating-to-exercise/
This resting fat loss differs greatly from adrenaline-induced lipolysis that floods that bloodstream with FFA affecting systemic function, raising inflammation via prostaglandin synthesis, and activating aromatase and raising estrogen. So quick fat loss is not advantageous especially as a person ages and PUFA is bound to accumulate. Peat provides a lengthy timeline of four years or more to correct the ratio of saturated fat to pufa in the tissues provided smart choices are made and cautions about raising stress or the metabolism too quickly because those can activate the stress response and slow progress.
“When we don’t eat for many hours, our glycogen stores decrease, and adrenaline secretion is increased, liberating more glucose as long as glycogen is available, but also liberating fatty acids from the fatty tissues. When the diet has chronically contained more polyunsaturated fats than can be oxidized immediately or detoxified by the liver, the fat stores will contain a disproportionate amount of them, since fat cells preferentially oxidize saturated fats for their own energy, and the greater water solubility of the PUFA causes them to be preferentially released into the bloodstream during stress.
In good health, especially in children, the stress hormones are produced only in the amount needed, because of negative feedback from the free saturated fatty acids, which inhibit the production of adrenalin and adrenal steroids, and eating protein and carbohydrate will quickly end the stress. But when the fat stores contain mainly PUFA, the free fatty acids in the serum will be mostly linoleic acid and arachidonic acid, and smaller amounts of other unsaturated fatty acids. These PUFA stimulate the stress hormones, ACTH, cortisol, adrenaline, glucagon, and prolactin, which increase lipolysis, producing more fatty acids in a vicious circle. In the relative absence of PUFA, the stress reaction is self limiting, but under the influence of PUFA, the stress response becomes self-amplifying.”
Fats, functions & malfunctions
http://raypeat.com/articles/articles/fats-functions-malfunctions.shtml