Fasted vs Overfed State (Updated: 2.15.17)
“How our body responds to a calorie deficit is largely dependent on our hormonal state. Your body is more concerned about avoiding a blood sugar crash than it is about maintaining muscle mass. That’s why during fasting we tend to convert large amounts of amino acids into glucose, which is stored in the liver as glycogen and then released to maintain blood glucose levels. Hormone status and presence of ketones can change how much protein we convert to glucose. The reason why our bodies still need glucose is because tissues like red blood cells and certain parts of the brain can only run on glucose. Instead of the body breaking down amino acids into glucose (gluconeogenesis), the body uses stored body fat as fuel. As the body shifts to fat as a primary fuel source, a by-product of fat metabolism begins to accumulate: ketones. The metabolic state of “ketosis” is normal and almost as old as time. Ketones are like small pieces of fat that are water soluble and given a few days or weeks, most of our tissues can shift their metabolism to burn ketones. The shift to ketosis solves two very important problems:
- It protects scarce blood glucose by shifting as much of our metabolic machinery as possible to a nearly limitless fuel supply. We have a day or two of liver glycogen, but even if we are relatively lean, we have months of stored body fat. A shift to ketosis saves scarce glycogen to be used to maintain minimal blood glucose levels.
- Ketosis halts gluconeogenesis. This spares muscle mass that would be very valuable in a state of prolonged starvation. In addition to blocking gluconeogenesis from amino acids, ketosis provides a sneaky alternative way to make glucose using the glycerol backbone of fats.
However, if we are overfed our brain no longer hears the fullness signal from leptin. When we are overfed on carbs, our liver and muscle glycogen are filled, but we still have excess free glucose in the bloodstream. Excess carbs are then converted to fat in the form of a short-chain saturated fat called palmitic acid. This palmitic acid is stitched to the glycerol molecule and packaged with proteins and cholesterol and the resultant molecule is called a VLDL. Palmitic acid has a very potent effect on our metabolism and our hormonal environment in that it decreases our sensitivity to leptin. Palmitic acid then causes the leptin resistance in the brain leads to our inability to feel full and is made from excess dietary carbs. Once we develop insulin sensitivity, the inhibitory systems in the liver are overwhelmed and blood glucose is converted into fats and VLDLs at such a high rate that escape into circulation, and it begins to accumulate in the liver. This is the beginning of non-alcoholic fatty liver disease (Paleo Solution, 69)”
How does the body use, store, and burn energy? (Updated: 2.24.17)
In a fed state, energy looks something like this:
- Food is absorbed and turned into glucose
- Rise in glucose (blood sugar)
- Pancreas makes insulin
- Insulin levels rise
- Insulin ushers blood sugar into cells for energy
- Blood sugar first gets stored as glycogen in the liver and muscles
- Extra blood sugar is stored as fat
In a fasted state, energy production looks something like this:
- Insulin levels drop
- Body burns stored energy (glycogen)
- The glycogen releases glucose (around 24-36 hour mark)
- The liver manufactures glucose from amino acids which is called gluconeogenesis (24-48 hour mark)
- Lipolysis begins to take place around the 48-hour mark which is the breakdown of fat for energy. Specifically, triglycerides.
- The triglyceride breaks down into a glycerol molecule and fatty acids
- Glycerol molecule is used as a form of gluconeogenesis so amino acids can be reserved for protein synthesis.
- The fatty acids make ketones for energy (Beta-HBA and acetoacetate)
Why is fasting used to help lose weight (Updated: 1.19.17)
The foods we eat are the initial and ongoing reason why we raise insulin levels in the first place. Over time, our bodies become blind to the signal insulin sends out after a meal. As a result, more insulin is pumped out to get the job done. This persistent call for insulin eventually leads to insulin resistance. While a change in the type of food may be a great start and lead to weight loss, we need to remember that all foods raise insulin. With insulin still being signaled to act after a meal, your body is still remaining insulin resistant. The goal of fasting is to break the insulin-resistance cycle. The goal is to sensitize the insulin receptors through fasting, which allows for very low levels of insulin for an extended period of time. Remember that obesity if a disease of hormonal imbalance. Our hormones like insulin, growth hormone, and adrenalin adapt to fasting in a variety of ways. By fasting, you can efficiently reduce your body’s insulin resistance, since it needs both persistent and high levels to remain resistant. Growth hormone is known to increase the availability and utility of fats for fuel. It also helps to preserve muscle mass and bone density. One of the most potent stimuli for GH secretion is fasting. Over a 5-day fast period, GH secretion more than doubles. Fasting increases adrenalin levels, starting at around 24-hours. 48 hours of fasting produces a 3.6% increase in metabolic rate, not the dreaded metabolic shutdown so often seen in caloric-reduction strategies (Obesity Code, 240).
We have about 40,000 calories of stored fat and about 2,000 calories of stored sugar (Guide to IF, 15).
What are some myths about fasting? (Updated: 1.20.17)
- Fasting breaks down muscle: breakdown of muscle tissue happens only at extremely low levels of body fat (4%). The body will preserve muscle mass until fat stores become so low that is has no other choice.
- The brain needs glucose to function: the body uses ketones as a major fuel source during prolonged fasting.
- Fasting will cause our basal metabolism to decrease (aka burn less calories): Daily caloric restriction does lead to decreased metabolism, so people have assumed that this effect would be magnified as food intake dropped to zero. Decreasing food intake is matched by decreased energy expenditure. However, as food intake goes to zero, the body switches energy inputs from food to stored fat. This strategy significantly increases the availability of food, which is matched by an increase in energy expenditure. Caloric-restricted diets that do not involve fasting inhibits hormonal adaptations. Adrenalin is not increased to maintain total energy expenditure. Growth hormone is not increased to maintain lean muscle mass. Ketones are not produced to feed the brain. Persistent exposure to decreased calories results in the body adapting by reducing energy expenditure. The intermittent nature of fasting does not allow for this to happen. As mentioned earlier, hormones act in accordance with fasting to maintain muscle, ramp up metabolism, and burn ketones for energy. (Obesity Code, 245).
What’s the deal with Intermittent Fasting?
Our body does a great job of converting fat into vital fuel during times of starvation. We can break down fat into ketones (esp Beta-HBA) which is a superior fuel for the brain. Researchers have determined that beta-HBA (in coconut oil), improves antioxidant function, increases the number of mitochondria, and stimulates the growth of new brain cells.
One of the most important processes in the body that is dictated by the mitochondria is programmed cell death, whereby cells commit suicide (apoptotic cell death). Intermittent fasting (IF) – a complete restriction of food for1-7 days at regular intervals throughout the year can achieve the same results as caloric restriction. Water is going to be the ultimate fast. If you’re drinking just water, after 24 hours your body will go into detox mode. With no food to eat, your body is finding glycogen in muscle, but over time your body will start to recycle diseased cells. It will break down proteins and reuse them, and it will get rid of stuff it doesn’t need. Your body’s ability to do that increases as you fast. A water-only fast is pressing on the gas all the way. (See more at: https://www.youtube.com/watch?v=z2Fi3AjGUYY) Fasting, as per Tim Ferris, is an effective way to purge precancerous cells (1.3.16, recommendations for 2016 with Kevin Rose) He does: 1 full day/wk, IF 16hrs/day, 3day 1x/month.
The pros of caloric restriction through Intermittent fasting (Updated: 1.20.17)
Caloric restriction provides neuroprotection by its minimizing apoptosis, enhancing mitochondrial energy production, decreasing mitochondrial free radical formation, and enhancing mitochondrial growth. Lowering caloric intake slows down aging, reduces age-related chronic disease, and prolongs life. It already has been proven to improve insulin sensitivity, reduces the body’s overall oxidative stress, triggers the expression of genes to manage stress and resist disease, and switches your body into fat-burning mode. All, in turn, help maintain a healthy microbiome. Fasting can do something besides enhance the health and function of the mitochondria. Its finally being shown in lab studies that caloric restriction prompts changes to gut bacteria, which may also be responsible for some of the calorie restrictions beneficial role in health. A study demonstrated that calorie restriction enriches strains of bacteria that are associated with increased lifespan and reduces those strains that are negatively correlated to lifespan.
Your body will start to go into a detox mode, over time our body will start to recycle diseased cells, breakdown and reuse proteins, and get rid of the stuff it needs. As you fast more, your body becomes better at doing that
Benefits of Fasting (Updated: 2.24.17)
By definition: Short is less than 24 hours. Long is 24-72 hours. Extended is 72+ hours
- 3+ day fasts can effectively reboot your immune system via stem cell-based regeneration (Tools of Titans, 24)
- Extended (5+ day) fasts are an effective cancer prevention strategy. Cancer cells that are in all of us just need to be pushed over the edge to be killed. Fasting clears out these damaged cells through a process known as autophagy (Guide to IF, 19). Fasting is important before cancer treatment because it slows rapidly dividing cells and triggers an energetic crisis that makes cancer cells selectively vulnerable to chemo and radiation (Tools of Titans, 31)
- Autophagy is a benefit of fasting where the body actually cleans out old junky proteins and subcellular parts The absence of nutrients makes the body prioritize which cellular parts to keep since we don’t have the energy to provide for all. If you don’t clear out these cells they sit around and create pro-inflammatory cytokines, thus damaging nearby cells. Autophagy also plays a role in removing amyloid-beta proteins in the brain, thus preventing Alzheimer’s (Guide to IF 5, 153)
- Neurological benefits. Fasting turns on the machinery for the production of BDNF → creation of new brain neurons. Fasting increases attention, acuity, focus, and memory due to the increase in BDNF. Also, insulin is inversely correlated to memory → lower insulin, raise memory (Guide to IF, 150).
- Powers up Nrf2 Pathway, which is your bodies own production of antioxidants, which assists in detoxification, decreased inflammation, and increased brain protective antioxidants (Grain Brain, 3)
- Helps control blood sugar and insulin levels, and gives your pancreas rest from producing insulin (Guide to IF, 17)
- Regular fasting can improve insulin sensitivity (Guide to IF, 15)
- The lowering of insulin levels helps lower excess sodium and water as insulin causes sodium and water retention in kidneys (Guide to IF, 47)
- Extended fasts may allow for a good cleaning out of excess waste through bowel movements that occur even after days without food (Guide to IF, 18).
- Fasting allows you to gain a real sense of when you are hungry and allows you to control your eating patterns.
- Extended fasts can help lower blood lipid levels (Cholesterol, LDL, Triglycerides, Inflammation markers, etc)(Guide to IF, 25).
- Sustained energy from burning body fat as fuel than burning food. One reason for this is because adrenaline is used to release stored glycogen and facilitate fat-burning. The increased adrenaline levels stimulates our fat burning metabolism (Guide to IF, 49). Increases lipolysis (Fat-burning)
- Anti-aging effects. Fasting raises growth hormone which stimulates the production of new cell parts. Growth hormone is known to increase the availability and utility of fats for fuel. It also helps to preserve muscle mass and bone density.
More on Autophagy (Updated: 2.24.17)
Autophagy: [aw-tof-uh-jee]: An act of self-cleansing or recycling. It is a process that not only clears out the old debris but also recycles these damaged components into molecules for energy or to make new parts. It gets rids of faulty parts, stops cancerous growth, and stops metabolic dysfunction (think obesity and diabetes).
- Increasing your bodies recycling program can lead to decreased inflammation (cause of all disease) and slow down the aging process (the foot is always on the gas but this will ease up on the pedal).
- Greater autophagy = fewer damaged parts = stronger and healthier organism = less inflammation, decreased aging
- How to boost autophagy: Through intense exercise, intermittent fasting, and/or a high-fat diet. Well, how much do I need to do to make it beneficial? 20-60 minutes of exercise per DAY → clearly the closer to 60 min the more potential benefit, 16-hour daily fasting seems to be appropriate, and 60-70% of calories from your diet coming from fat (there is some wiggle room here on the %).
- For those who are not convinced: If autophagy does not happen in the body and you do not clear out these damaged cells and debris, they sit around and create pro-inflammatory molecules (cytokines) that damage nearby cells. Autophagy removes these damaging molecules including removing amyloid-beta proteins in the brain….preventing or slowing Alzheimer’s Disease!
- If someone asks what autophagy is you tell them it is a bodily process that recycles toxins into useable parts. It is accomplished through exercise, fasting, and a high-fat diet!
Does drinking bulletproof coffee or bone broth negate the benefits of the fast? (Updated: 2.24.17)
Using bulletproof coffee or bone broth is an effective way to you get through a fast. It can provide the level of satiety needed to get you through the painful moments during an extended fast. The purpose of the coffee or broth would simply be to make the fast less painful. If fasting is going well and you can push through without it then you do not need it. Short fasts would be best served without the coffee or the broth. During longer and extended fasts it may be of benefit to drink bulletproof coffee early in the fast and then omit once 24 hours in. As mentioned already, if it helps you get through the fast then drink it as needed. One of the main benefits of fasting is lowering insulin and improving insulin sensitivity. With that being said, bone broth would be my second option as the protein in the broth can have an effect on insulin as well as shut off autophagy. Bulletproof coffee with Ghee instead of butter is also a better option as GHEE is the fat from the butter. This eliminates the protein and carb that is naturally in butter. MCT oil is a fat that will help raise ketones which can provide an immediate source of energy for your brain as it easily passes through the blood brain barrier. In general, if you want the FULL benefit of the fast (i.e. autophagy) then black coffee, tea, and water will serve you best. Next would be bulletproof coffee with ghee and MCT oil (add some cinnamon as well). Finally, bone broth can serve as a way to keep you satiated during the fast. Not every fast is created equal, so have fun with it and try different techniques. The best fast is the one that works best for YOU.
How often should I Fast? (Updated: 2.24.17)
By definition: Short is less than 24 hours. Long is 24-72 hours. Extended is 72+ hours
- Short – Daily: 16 hour+ Intermittent fasting
- Long – Weekly: 24-36 hour fast
- Longer – Monthly: 48 hour fast
- Extended – Quarterly: 3-5 day fast
- Extended – Yearly: 7 day fast
Tips when Fasting (Updated: 2.24.17)
- Add sea salt to your drinks. Insulin retains water so when fasting we excrete salt and water. Adding salt helps guard against fatigue and lack of energy (Guide to IF, 13)
- For longer fasts (3-5 days) you can add bone broth and bulletproof coffee to help with satiety. Although this is not a pure fast, you will still receive most of the benefit of fasting (Guide to IF, 18)
- For longer fasts, the week prior to the fast get into ketosis first. This will help ease the transition to fasting through your ability to up-regulate fat metabolizing hormones (Guide to IF, 16).
- Longer Fasts: Be careful with the supplements you take. Supplementing may send mixed signals to your body. When we are fasting we are producing good reactive oxygen species; we don’t want to down regulate this benefit that comes from fasting (Guide to IF, 18).
- Longer fasts may benefit from taking a multivitamin
- Magnesium is one of the few vitamins/minerals that lower while fasting. (Guide to IF, 81)
- 3g of BCAA during exercise (Tools of Titans, 25)
- Coffee with MCT OIL during 1st, 2nd day to get into ketosis as quickly as possible to avoid muscle wasting then omit (Tools of Titans, 25)
- Drink mineral water or green tea to stimulate metabolism and weight loss, cinnamon to suppress hunger (add to black coffee) (Guide to IF, 8, 230).
- Make sure you are mentally prepared for the fast
- 16-hour fasts generally provides the right balance of autophagy (Tools of Titans, 60)