Insulin etiketine sahip kayıtlar gösteriliyor. Tüm kayıtları göster
Insulin etiketine sahip kayıtlar gösteriliyor. Tüm kayıtları göster

11 Aralık 2015 Cuma

In starvation or ketosis, protein should have NO EFFECT on blood glucose level, not RAISE it.

From Blood Sugar is Stable:-

In a healthy person, BG (blood glucose) is held at a fairly constant value with slowly-varying glucose inputs (except after high-GL meals, which produce rapidly-varying glucose inputs) by a NFB (negative feed-back) loop. See Blood Glucose, Insulin & Diabetes.

When protein is eaten, this produces a glucagon response from pancreatic alpha cells, which tries to raise blood glucose level by stimulating the liver to convert liver glycogen plus water to glucose. Protein also produces an insulin response from pancreatic beta cells, which tries to lower blood glucose level by a) increasing glucose uptake from the blood and b) inhibiting HPG (hepatic glucose production). The net result is no change in BG level.

In extended fasting or on VLC (very low carbohydrate)/ketogenic diets, there's no liver glycogen left after ~1 day.
The glucagon response has no effect on HGP.

The insulin response still has an effect, until physiological IR* develops.
∴ Blood glucose tries to decrease, but the HPAA keeps it steady by raising cortisol level.

RE How eating sugar & starch can lower your insulin needs: Blood glucose level on a VLC/ketogenic diet can be RAISED, due to the BG NFB HPAA (hypothalamic pituitary adrenal axis) loop not having a precise set point with the cortisol/adrenaline response (hyperglycaemia is not fatal, whereas hypoglycaemia can be fatal, as the brain always needs some glucose to function (~50%E from glucose)).

So, how come people on LCHF (low carbohydrate, high fat) diets can have normal or slightly low BG levels?

1. Luck. The BG NFB HPAA loop isn't very precise.

2. Excessive intake of Booze. Ethanol inhibits HGP (dunno about RGP (renal glucose production)).

3. Insufficient intake of Protein. This deprives the liver & kidneys of glucogenic amino acids (Alanine & Glutamine are the 2 main ones), forcing BG down and making the HPAA run open-loop and raise cortisol level. There's another source of Alanine & Glutamine available - Lean Body Mass. Uh-oh!


Consuming more protein on extended fasting or a VLC/ketogenic diet can result in higher BG level for three reasons.

1. It allows the HPAA to run closed-loop, as it's supposed to.

2. The lack of a 1st phase insulin response in people with IR/IGT/Met Syn/T2DM* results in a temporary BG level spike with the intake of rapidly-absorbed proteins e.g. whey. There's an unopposed glucagon response, until the 2nd phase insulin response begins.

See http://care.diabetesjournals.org/content/early/2015/11/29/dc15-0750.abstract

*Long-term drastic carbohydrate restriction kills the 1st phase insulin response! See http://carbsanity.blogspot.co.uk/2013/10/insulin-secretion-in-progression-of.html

P.S. This only applies to people who have sufficient liver glycogen, due to them eating some (50 to 100g/day, say) carbohydrate.

3. Hepatic Insulin Resistance results in the insulin response inadequately suppressing Hepatic Glucose Production. As 50g of protein (an 8oz steak, say) yields ~25g of glucose from glucogenic amino acids, there's an increase in the amount of glucose entering circulation, which raises BG level.

See http://bja.oxfordjournals.org/content/85/1/69.long

4 Aralık 2015 Cuma

Low-carbohydrate High-fat diets: Green flags and Red flags.

Fun with flags. But first, a poem!

Atkins Antidote


Eating low carbohydrate what threat that poses

Do my friends think I’m suffering from halitosis?

I’ve got these sticks for measuring ketoacidosis

I’m taking supplements but I don’t know what the dose is

I’m trying hard to keep in a state of ketosis

I’m not sure what the right amount of weight to lose is

I’m sure I’ve put on a pound just through osmosis

Is eating this way risking osteoporosis

Are my kidneys wrestling with metabolic acidosis

My store of liver glycogen I don’t know how low is

Who knows what the glycemic load of oats is

Does anyone know if I can eat samosas?



Ian Turnbull


I do. The answer's "No!" :-D
From https://forum.nationstates.net/viewtopic.php?f=23&t=13567&start=8925


The Green flags...

1. For a person with Insulin Resistance, an ad-libitum low-carb diet results in more weight loss than an ad-libitum high-carb diet.

See How low-carbohydrate diets result in more weight loss than high-carbohydrate diets for people with Insulin Resistance or Type 2 Diabetes , for an explanation.

2. For a person with Type 1 Diabetes Mellitus (T1DM), a lowish-carb (~100g/day), highish fat diet results in minimal disturbances to blood glucose levels and minimal bolus insulin doses.

See Diabetes: which are the safest carbohydrates? , to see which foods should comprise the ~100g/day. N.B. As ~50% of dietary proteins can be converted into glucose by gluconeogenesis, ~100g/day of slow-digesting proteins such as meats, eggs & cheeses can contribute ~50g/day of glucose towards the ~100g/day total.

3. For a person with LADA or MODY, see 2.

4. For a person with Type 2 Diabetes Mellitus (T2DM), a LCLF 600kcal/day Protein Sparing Modified Fast can normalise BG in 1 week and reverse T2DM in 8 weeks (provided there are sufficient surviving pancreatic beta-cells).

See http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3168743/
"After 1 week of restricted energy intake, fasting plasma glucose normalised in the diabetic group (from 9.2 ± 0.4 to 5.9 ± 0.4 mmol/l; p = 0.003)."

"Maximal insulin response became supranormal at 8 weeks (1.37 ± 0.27 vs controls 1.15 ± 0.18 nmol min−1 m−2)."

After 8 weeks, transition to a diet based on whole, minimally-refined animal & vegetable produce.

See also http://www.fend-lectures.org/index.php?menu=view&id=94

As Insulin Resistance is multi-factorial, ALL of the potential causes need to be addressed. Once this has been done, IR should be reversed, allowing restrictions on dietary carbohydrate intake to be lifted. See also Can supplements & exercise cure Type 2 diabetes?

The Red flags...

The low-carb diet is a temporary patch to ameliorate IR/IGT/Met Syn/T2DM, a bit like replacing a failed circuit-breaker by sticking a nail in its place, to allow the house to function while you fix the problem by buying a new circuit-breaker. Although the house functions fine with a nail in place of a circuit-breaker, you wouldn't want to spend the rest of your life without a working circuit-breaker protecting the house.

So, why do low-carbers seem to want to spend the rest of their lives using a temporary patch to ameliorate their IR/IGT/Met Syn/T2DM?

Long-term use of very-low-carb, very-high-fat diets is not recommended.

1. Cortisol level can gradually increase, resulting in increasing fasting BG level. See How eating sugar & starch can lower your insulin needs.

2. If you do too much high-intensity exercise, you may momentarily black-out, fall and hurt yourself. See "Funny turns": What they aren't and what they might be.

3. Some people seem to gradually go bat-shit crazy. See Can very-low-carb diets impair your mental faculties? Read the comments in https://www.facebook.com/TheFatEmperor/posts/1633434020253792. Do the behaviours of Ivor Cummins & Gearóid Ó Laoi seem normal to you?

4. Insulin Resistance is bad, mmm-kay? See Lifestyle-induced metabolic inflexibility and accelerated ageing syndrome: insulin resistance, friend or foe?

5. Dyseverything elseaemia isn't addressed. See Type 2 diabetes: between a rock and a hard place , Type 2 diabetes: your good signalling's gonna go bad and When the only tool in the box is a hammer.

6. Dietary deficiencies may develop. See Rigid diets & taking loadsa supplements to compensate for them.

7. High-fat diets with no energy deficit result in high postprandial TG's. Postprandial lipaemia is atherogenic. See Ultra-high-fat (~80%) diets: The good, the bad and the ugly.

There may be more but I'm knackered, so I'm Publishing!

19 Aralık 2014 Cuma

Variations in weight change for a given Calorie change - An Engineer's Perspective.

Another techie post, inspired by Insulin Doesn't Regulate Fat Mass. Consider the inverting amplifier using an Op-Amp, below:-
From HERE

As the amplifier is inverting (i.e. a ↑ input on Vin results in a ↓ output on Vout), the feedback from Vout via R2 opposes Vin via R1 at the - terminal of the Op-Amp.

If R1 = R2 and Vin changes from 0V to 1V, the change in V- (the voltage on the - terminal of the Op-Amp) varies with A (the magnitude of the Op-Amp gain) as follows*:-

A_____________Change in V-(V)
_____________0
1,000,000_____~0.000001
1,000_________~0.001
100___________~0.01
10____________~0.08
8_____________0.1
5_____________~0.14
3_____________0.2
2_____________0.25
1_____________~0.33
0_____________0.5

As the body operates on biochemical principles, slopes of input/output transfer functions aren't steep at their steepest points. E.g.
From http://bja.oxfordjournals.org/content/85/1/69.long


Therefore, the gains in the various parts of the Leptin "adipostat" NFB loop are not very high. Therefore, there will be a significant variation in weight change vs Calorie change, and there will be significant variations in the variation due to loop gain variations from person to person.

Insulin Resistance makes the slopes of  the above input/output transfer functions shallower, reducing the gain in the system. This increases the variation in weight change vs Calorie change. For ways to reduce Insulin Resistance, see Insulin Resistance: Solutions to problems.

*In case anyone thinks that I've made the numbers up, here's the maths:-
Current in/out of the - terminal of the Op-Amp = 0.
∴ IR1 = IR2
I set R1 = R2 to keep the maths simple. By Ohm's Law, V = I * R.
∴ VR1 = VR2
With a 0V input:-
All currents & voltages = 0.

With a 1V input:-
VR1 = 1 - V-
VR2 = V- - Vout.  As Vout is negative, - Vout is positive.
- Vout = A * V-
∴ VR2 = V- + (A * V-)
∴ 1 - V- = V- + (A * V-)
Rearranging:-
1 = (2 * V-) + (A * V-)
Dividing both sides by V-:-
(1/V-) = 2 + A
∴ V- = 1/(2 + A)

6 Eylül 2014 Cumartesi

Another penny drops: Why severe hyperinsulinamia can occur with a small increase in exogenous carbohydrate intake.

This blog post is a result of Vim's comments in the previous blog post. A penny suddenly dropped!
From http://bja.oxfordjournals.org/content/85/1/69.full

Insulin has a Chalonic (inhibitory) action on blood glucose level (via the liver, muscle mass & fat mass), blood FFA level (via fat mass) and blood ketone body level (via the liver).

As mentioned in the comments, GHB has a stimulant effect - up to a certain level of blood GHB. Beyond that level, there's a powerful sedative effect. This is because at low levels of exogenous ketone body input, insulin secretion increases slightly to reduce hepatic ketogenesis.

At a certain level of exogenous ketone body input, hepatic ketogenesis falls to zero and cannot be reduced any further. Any slight increase beyond this point in exogenous ketone body input, results in a large increase in insulin secretion, as the pancreas increases Ketone body-Stimulated Insulin Secretion to maximum in a (failed) attempt to reduce blood ketone body level.

Exactly the same thing happens with exogenous carbohydrate or BHB input.

At a certain level of exogenous carbohydrate input, hepatic glucogenesis falls to zero and cannot be reduced any further. Any slight increase beyond this point in exogenous carbohydrate input, results in a large increase in insulin secretion, as the pancreas increases Glucose-Stimulated Insulin Secretion to maximum in a (failed) attempt to reduce blood glucose level.

31 Temmuz 2014 Perşembe

Nonequilibrium thermodynamics and energy efficiency in weight loss diets, by Richard D Feinman and Eugene J Fine.


From http://www.caloriegate.com/the-black-box/9-pictures-that-prove-beyond-a-reasonable-doubt-that-calories-dont-count

From Nonequilibrium thermodynamics and energy efficiency in weight loss diets:-

"Conclusion
Emphasis on kinetics and nonequilibrium thermodynamics provides a conceptual framework for understanding the effect of macronutrient composition on maintenance and change of body mass and possibly for analysis of adipocyte metabolism in general. The simple model presented is intended to be consistent with a general shift away from equilibrium thermodynamics and towards a more dynamic analysis of cellular processes."

Sounds plausible. There's only one thing wrong with Feinman et al's article - it's completely wrong!

Consider two rooms:-

Room "A" has an adjustable heater. The heater is adjusted until the room temperature is 20°C.

Room "B" has a radiator, controlled by a wall-stat set to 20°C. The radiator is on, and the room is at 20°C.

We have two rooms of the same size, at the same temperature.

If you plug in & turn on a 2kW fan heater in each room, what happens to the temperature in each room?

Room "A" gets warmer, because there is 2kW more heat power entering it.

Room "B" stays at 20°C, because the wall-stat reduces the heat power from the radiator by 2kW.

The human body stays at 37°C ±~2°C, because there's a Negative Feed-Back loop adjusting the heat power produced, via UCP's, futile cycles, thyroid hormones, shivering and heat conservation/wasting behaviours.

∴ Variable heat power generation due to variable Dietary Efficiency doesn't change Eout.


EDIT: By request, here's Figure 1 from the above study.

This suggests that fat mass & therefore weight can increase indefinitely - at maintenance energy intake, due to the effect of insulin on HSL. This, of course, is quite impossible!

From The Energy Balance Equation:-

Change in Body Stores = Ein (corr for digestion) - Eout (BMR/RMR + TEF + TEA + SPA/NEAT)
__BMR/RMR & TEA ∝ weight
weight → Eout
__If Ein = constant, Eout (Ein - Eout) → weight
weight → weight
∴ Figure 1 is wrong.

4 Temmuz 2014 Cuma

How low-carbohydrate diets are (incorrectly) explained to work.

Having explained how low-carbohydrate diets work, here are a few ways in which they don't work.
Uh, nope!

1. Hormonal clogs: This is a term used by Jonathan Bailor. I don't think he's referring to wooden shoes! The "clog", I'm guessing, is supposedly caused by that dastardly hormone insulin. Uh, nope!

See the following plots of RER vs exercise intensity after being on high-fat diet or low-fat diet.
RER = 0.7 ≡ 100%E from fat. RER ≥ 1.0 ≡ 100%E from carb.

The low-fat diet results in higher RER, so the body is burning a higher %E from carb and a lower %E from fat.

However, this doesn't make any difference to weight loss, as it's merely a substrate utilisation issue. In addition, when the body is burning a higher %E from carb, this depletes muscle glycogen stores faster, which lowers RER during the course of the exercise. So, it's not a problem.


2. Insulin: This is Gary Taubes' hypothesis. Insulin makes your body store carbohydrates as body fat. Uh, nope!

The only time that there's significant hepatic DNL is when there's chronic carbohydrate over-feeding. If you eat sensibly, there's no significant hepatic DNL.


3. A Calorie isn't a Calorie, where weight change is concerned: This is Richard D Feinman's hypothesis. "A calorie is a calorie" violates the second law of thermodynamics, therefore there's a metabolic advantage with low-carbohydrate diets. Uh, nope!

Where to start? Evelyn Kocur knows her Physics, so I'll start there. See The first law of thermodynamics (Part 1) and The first law of thermodynamics (Part 2).

From Second Law of Thermodynamics:-
"Living organisms are often mistakenly believed to defy the Second Law because they are able to increase their level of organization. To correct this misinterpretation, one must refer simply to the definition of systems and boundaries. A living organism is an open system, able to exchange both matter and energy with its environment."

People on ketogenic diets excrete very few kcals as ketone bodies. See STUDIES IN KETONE BODY EXCRETION. There is no significant Metabolic Advantage with low-carbohydrate diets.

How low-carbohydrate diets result in more weight loss than high-carbohydrate diets for people with Insulin Resistance or Type 2 Diabetes.

See The Battle of the Diets: Is Anyone Winning (At Losing?) for trials where insulin resistant people get more weight loss on low-carbohydrate diets than on high-carbohydrate diets, and insulin sensitive people get more weight loss on high-carbohydrate diets than on low-carbohydrate diets.

If Gary Taubes' carbohydrate/insulin hypothesis of obesity was correct, everyone would get more weight loss on low-carbohydrate diets. This isn't the case, therefore Gary Taubes' hypothesis is not correct.

Although insulin is involved, it has nothing to do with "Hormonal clogs" or "Insulin fairies"!
The Aragon Insulin Fairy

The Energy Balance Equation


Change in Bodily Stores = Energy in - Energy out, where... 

Energy in = Energy entering mouth - Energy exiting anus, and... 

Energy out = BMR/RMR + TEF + TEA + SPA/NEAT

See The Energy Balance Equation to find out what the above terms mean.

People with Insulin Resistance (IR), Impaired Glucose Tolerance (IGT) & Type 2 Diabetes (T2DM) have excessive insulin secretion in response to meals (postprandial hyperinsulinaemia). See Hyperinsulinaemia and Insulin Resistance - An Engineer's Perspective.

People with Insulin Resistance (IR), Impaired Glucose Tolerance (IGT) & Type 2 Diabetes (T2DM) also have impaired/no 1st phase insulin response to a sudden rise in blood glucose level. This introduces a time-lag into the negative feed-back (NFB) loop that regulates blood glucose level. If the input rise-time is less than the time-lag in a NFB loop, the output of the NFB loop overshoots. This is standard NFB loop behaviour. Trust me, I'm a retired Electronic Engineer. I've observed this (too) many times!

1. On a high-refined-carbohydrate or high-GL diet, blood glucose level rises rapidly, with a rise-time that's less than the time-lag in the blood glucose regulation NFB loop. Insulin secretion from the pancreas overshoots in a positive direction. The resulting massive postprandial hyperinsulinaemia results in down-regulation of insulin receptors in the brain, which reduces insulin action in the brain. When the insulin level eventually falls to normal a few hours later, the brain interprets a normal insulin level as hypoinsulinaemia. Hypoinsulinaemia results in ravenous hunger, as insulin is a short-term satiety/satiation hormone in the brain (leptin is a long-term satiety/satiation hormone in the brain). Ravenous hunger results in over-eating. Energy in increases. Postprandial hyperinsulinaemia also results in postprandial sleepiness. Energy out decreases. Bodily stores increase. There are also accusations of sloth & gluttony!

2. On a low-carbohydrate or low-GL diet, there are small fluctuations in blood glucose & insulin levels. There is no ravenous hunger. There is much less/no over-eating. Energy in decreases. There is no massive postprandial hyperinsulinaemia. There is much less/no postprandial sleepiness. Energy out increases. Bodily stores decrease.

In addition, there is a loss of water weight due to a loss of liver & muscle glycogen. This can be ~2kg in one day (it varies from person to person). Kidneys can increase their output of urine for hormonal reasons. This can increase water weight loss to ~5kg. See Why counting Calories and weighing yourself regularly can be a waste of time.

There are also other hormones involved. For a Facebook discussion with James Krieger that led to the updating of this post, see https://www.facebook.com/james.krieger1/posts/10153228943648587

P.S. In Metabolic Ward studies, food intake is tightly controlled, so postprandial hunger doesn't result in over-eating. Energy expenditure is also controlled, so postprandial sleepiness doesn't significantly affect energy expenditure. This is why varying Fat:Carb ratios (with Protein held constant) makes no significant difference to weight in a Metabolic Ward. See Energy intake required to maintain body weight is not affected by wide variation in diet composition.

P.P.S. Inter-personal variations in postprandial hyperinsulinaemia, postprandial sleepiness & energy out explain the inter-personal variations in weight gain seen under hypercaloric conditions.

P.P.P.S. Insulin Resistance can be fixed in the long-term. See Insulin Resistance: Solutions to problems.

Type 2 Diabetes can be fixed in the long-term. See Reversing type 2 diabetes, the lecture explaining T2D progression, and how to treat it.

Aim to fix the problem in the long-term. If a long-term fix isn't possible (due to excessive destruction of pancreatic beta cells), use a low-carbohydrate diet as an adjunct to medication.

26 Haziran 2013 Çarşamba

Resistance is useless!

...said the Vogon guard. If that means nothing to you, watch this...


You probably know all about Insulin Resistance (IR) if you've read my blog for some time, as I may have mentioned it once or twice ;-) There's also Leptin Resistance (LR) in the brain, which reduces the amount of appetite suppression that leptin is supposed to produce. Robb Wolf's just written about Adrenaline Resistance (AR?) and chronically-high serum cortisol seems to induce Cortisol Resistance (CR?) in the hippocampus, resulting in poor short-term memory.

When the level of "X" in the blood is low most of the time, "X" receptors in the body up-regulate, so when the level of "X" in the blood goes high, it has an effect. When the level of "X" in the blood is high all of the time, "X" receptors in the body down-regulate, so when the level of "X" in the blood goes higher, it has a reduced effect.

The above suggests that regularly "grazing" on food is not a good idea, as this results in a fairly constant slightly elevated serum insulin level. Eating a meal, not eating for a few hours then eating another meal results in high serum insulin while the meal is being absorbed and low serum insulin for the rest of the time.

8 Haziran 2013 Cumartesi

Gizmag: Injectable nanoparticles maintain normal blood-sugar levels for up to 10 days.

Fascinating technology featured in Gizmag & posted by someone HERE.
The nano-network that releases insulin in response to changes in blood sugar
"The injectable nano-network is made up of a mixture that contains nanoparticles with a solid core or insulin, modified dextran (which is commonly used to reduce blood viscosity), and glucose oxidase enzymes. When exposed to high levels of glucose, the enzymes convert glucose into gluconic acid, which breaks down the modified dextran to release the insulin. The gluconic acid and dextran, which are biocompatible, dissolve in the body, while the insulin brings the glucose levels under control.

The nanoparticles are given a positively or negatively charged biocompatible coating so that when they are mixed together, they are attracted to each other to form a “nano-network.” The positively charged coatings are made of chitosan, a material found in shrimp shells that has also found applications in self-healing car paint, while the negatively charged coatings are made of alginate, a material normally found in seaweed."

Wow! Cool bananas!

5 Haziran 2013 Çarşamba

When the only tool in the box is a hammer...

Everything that needs fixing looks like a nail.
What are the action and reaction forces when a hammer hits a nail?
People with diabetes mellitus are issued with blood glucose meters - and nothing else.

For people with type 1 diabetes, that's fine. They lack insulin, so they have to inject insulin in the right amounts & types to keep their blood glucose levels within reasonable limits. Applying Bernstein's Law of small numbers by reducing glycaemic load to a minimum keeps blood glucose levels within reasonable limits (between 3 & 7mmol/L) most of the time. See also The problem with Diabetes.

For people with type 2 diabetes and a fat belly (~85% of type 2 diabetics), that's not fine. Their disease is a disease of chronic excess fuel intake relative to fuel oxidation, causing dyseverythingaemia (hyperglycaemia, hypercholesterolaemia, hypoHDL-cholesterolaemia, hyperNEFAaemia, hypertriglyceridaemia, hyperuricaemia, etc). People who have type 2 diabetes don't have only postprandial hyperglycaemia - they also have postprandial hypertriglyceridaemia. See Postprandial lipoprotein clearance in type 2 diabetes: fenofibrate effects.

However, because the only tool in their box is a blood glucose meter, their disease looks like a disease of hyperglycaemia only. Applying Bernstein's Law of small numbers by reducing carbohydrate intake to a minimum keeps blood glucose levels within reasonable limits, but makes everything else worse if energy from carbohydrates is replaced by energy from fats.

Only if energy from carbohydrates is reduced AND energy from fats isn't increased to compensate (i.e. eat a LCLF PSMF or Modified PSMF), does carbohydrate restriction help people with type 2 diabetes.