Six common beliefs addressed, Part 12

1. Why does fasting cause blood glucose to rise? I thought it was suppose to make it low instead.

When you fast, insulin levels drop and this can cause a rise in blood glucose through different mechanisms. A few causes are listed below.

• When insulin levels drop, your body has access to its fat stores. Lipolysis is the breaking down of fat for fuel. This breaks down triglycerides. Triglycerides are made up of three units of fatty acids and one unit of glycerol. Glycerol is a component of fatty acids in fats. It is released when this stored fat is broken down (metabolized) for energy. It then enters into the bloodstream and transferred to the liver, where it can be converted to glucose. So, when you burn fat, you release glucose from it and it causes a rise in blood glucose.
• When insulin levels drop, counter regulatory hormones like cortisol go up. Cortisol upregulates the body's production of glucose and blocks the effects of insulin to stop its clearance. This causes a rise in blood glucose, which is more common in the morning, but can also occur with exercise. Most stress hormones cause this same effect using different pathways.
• With lower insulin levels, because of no exogenous glucose, glucagon ramps up gluconeogenesis and more glucose is released. This effect is more exaggerated in people with insulin resistance, but it is transient and will normalize with better insulin expression.

All of these processes are caused by the body going into a catabolic mode. It is no longer storing, but breaking things down, so it can use them. If the glucose is not entering from the outside (eaten), then it can only be coming from the inside. This is a good thing. You want this to happen, because excess glucose helps drive the disease. You want glucose to be released from storage and used for fuel. This will improve insulin sensitivity. You also want these glucose producing mechanisms to normalize so you can better regulate your blood glucose.

The disease is not a disease of high blood glucose, it's a disease of poor blood glucose regulation. Proper blood glucose regulation is when they body does not produce glucose when not needed and produces it when it does. It is not dependent on exogenous glucose and maintains a normal blood glucose set point. 

Keep an eye on this. It should improve in a few weeks. If it doesn't, shorten your fasts because you do not want to further deteriorate your blood glucose regulation due to these erratic ups and down. The trend should always be improvement. When there is none, you need to change what you are doing. 

2. Fasting only works because it restricts calories in the long run and will eventually slow down metabolism.

Intermittent fasting balances the body's fed (anabolic) and fasted (catabolic) states, through complex neuroendocrine feedback loops of which calories have very little input. Your body is not like a box that is emptied, with precisely the same amount of things it was filled with. It's much more complex, as things that go into it are sorted and distributed. Not all things are used and not all things are used in the same way. Instead of a box, the body is more like a mailroom, constantly analyzing, sorting and redistributing, depending on the items that are being shipped. This is because this feedback loop is affected by many other factors, not just the amount of calories. Food timing, frequency, macronutrient composition, etc. all give this complex system information for it to adapt accordingly. It can be efficient at what it does or it can not.

Metabolism will always go into energy conservation mode, when body fat is challenged. If metabolism did not adapt to available food, we would all be dead. Our metabolism is a complex adaptive system. Complex being the operative word, since not all forms of food restriction lead to the same outcome. How persistent and how extreme this adaption becomes, is dependent on the weight loss method used.

• The caloric restriction method. This signals to the body that there is food around, but not enough of it. This causes for metabolism to have to slow down, since it has no other choice. The macronutrient composition of these diets, enhances this effect through its interference with blood glucose homeostasis. 
• The intermittent fasting method. This causes an entirely different effect, on the metabolic rate, than classic caloric restriction. This type of fasting is a low level stress, on the body, that is hormetic. Short fasts signal the body that there is enough food, it just has to wait for it. For this reason, it is not forced to lower its metabolic rate. On the contrary, the metabolic rate speeds up. Stress hormones rise to keep blood glucose steady and the drop in insulin allows the body to tap into its fat stores and burn them for fuel. The wait for food is just not long enough to become detrimental. We evolved to wait to eat. Food was not magically available and at our disposal for most of our history on earth.
• The extended fasting method. Once the beneficial period of a short term fast passes, when the metabolic rate speeds up, the body is forced to reverse and go into energy conservation. At first, this seems like it's not a big deal. After all, once you eat again, it should speed back up. But, it doesn't. The body continues to conserve energy. Worse, it stores rather than burns, everything you eat, in order to prepare for the next period of starvation. With each extended fasting exposure, the body learns to store more and more. It becomes a better fat storage machine.

So, if you don't want your metabolism to adapt to better energy conservation, do not practice forms of "starvation". To the body chronic caloric restriction and extended fasting is starvation.

3. Will intermittent fasting become easier with time?

For the vast majority, yes, but for many others no. Until a fasting regimen is tried and sustained, for a period of time, it is unknown for who it will get easier and for who it won't. There are multiple reasons why some are unable to fast successfully.

The most common reason is attempting fasts that are too long or done incorrectly. You should never fast for longer than 3 consecutive days (72 hours), once a week, and only if you have substantial weight to lose. The less body fat you have, the less the benefits you will have from fasting. When body fat levels start to decline, fasting lengths should be shortened. A good sustainable fasting protocol is a 16-18 hour water only fast, daily. Fasting should be water only, as eating or drinking anything else is basically caloric restriction and not a true fast.

More is not better. Fast according to what your body can do comfortable with water only. If that's only 12 hours a day, then that is enough to obtain benefits. You should not fast for less than 12 hours a day, in order to better regulate blood glucose.

Other reasons for discomfort during a fast:

• Insulin increases the sympathetic nervous system. When insulin levels decrease rapidly through fasting, it can affect digestion motility, sleep and the release of stress hormones.
• High levels of insulin encourage clearance of all amino acids except one, tryptophan. If a lot of tryptophan is available, your body will have the ability to make serotonin. When insulin levels decrease rapidly, serotonin can also decrease. This can cause depression, anxiety and lethargy in some people.
• Thyroid hormones oppose the action of insulin. When insulin levels decrease rapidly, it can affect thyroid hormones.
• Some people are much more prone to electrolyte imbalances, even on very short fasts, and this can cause a wide array of uncomfortable symptoms.
• Keeping erratic fasting schedules. The body likes to develop a circadian rhythm of predictable fasting and feeding times. It basis its entire hormonal homeostatic profile on these rhythms. Fasting and feeding at constantly shifting times, will cause hunger during fasting or loss of appetite during eating. This will disrupt your fasting and feeding cycle.
• Compromised metabolic pathways that help with glucose production and fatty acid oxidation can cause other symptoms. These compromised pathways can prevent you from efficiently metabolizing fat causing lipid abnormalities, affecting thyroid hormones and causing persistent hypoglycemia.
• Conditions that are dependent in the homeostasis of the above can be affected by fasting. For example, migraine sufferers can experience triggering of headaches.

Fasting lowers and normalizes insulin levels that have been chronically high and/or erratic for decades. When insulin is suddenly lowered, you can expect side effects to occur. Insulin is not just solely responsible for glucose regulation, it also affects many other metabolic systems, in our bodies, all of which are now compromised due to insulin resistance.

For the most part, all of these side effects can be mitigated with a well formulated carbohydrate restricted diet. Carbohydrate restriction is the primer to slowly allow the proper regulation of blood glucose and adjust insulin production/expression. 

4. Are processed foods toxic?

Not inherently. The only foods that are toxic, are the ones that interfere with proper blood glucose regulation and there are many non-processed foods that do this. Processed foods are simply more likely to have a macronutrient profile that causes blood glucose abnormalities. 

5. Are carbohydrate restricted diets more costly? 

Only if you insist on making them so. 

Purchasing everything grass-fed and organic, which as nothing to do with metabolic health, can put an undue burden on your wallet. Purchasing specialty products like protein bars, shakes and drinks, packaged foods labeled "keto" and expensive ingredients to try and recreate Standard American Diet fare can break the bank and become unsustainable. 

If you just stick to meat and vegetables, you should see no difference in food costs or even a lowering of it. 

6. Isn't consumption of carbohydrates only a problem when excess calories are consumed?

No. Consumption of carbohydrates is only a problem because of their effect on blood glucose homeostasis. 

All diets work the same way - they effect blood glucose regulation which in turn effects insulin. All weight loss and gain is mitigated through insulin. All fat loss is mitigated through leptin. Leptin is a slave to insulin. 

Restriction of calories effects blood glucose homeostasis, lowering insulin and causing the famous water weight loss that everyone becomes excited about and makes them believe the diet is working. Unfortunately, that's where the benefits end. The restriction simply does not effect blood glucose profoundly enough to get past the temporary effect on insulin and get to the long term effect on leptin. There are many reasons for this. 

• Restriction of calories cannot be sustained long enough.
• Restriction of calories causes a doubling down effect of the starvation response after the initial lowering of insulin. 

Basically, it appears that the restriction of calories has a negative effect on leptin, regardless of its initial positive effect on insulin. 

So restriction of calories, no matter what diet used, is a failure for addressing overweight/obesity/diabetes. You will get much more bang for your buck if you address the root cause instead, which is blood glucose regulation. Everything else happens downstream from blood glucose, so you have to address it first. You have to address it with a protocol that can be sustained long term in order to profoundly effect these downstream metabolic processes.