This episode we will discuss everything you need to know about intermittent fasting. Intermittent fasting has gained tremendous popularity in health and fitness as a way to lose fat, live longer, and even build muscle. Unlike many popular diets, intermittent fasting has the backing of scientific research, including massive 2017 study analysis by the International Society of Sports Nutrition.
Before making any drastic lifestyle changes always check with your doctor before starting. Intermittent fasting might not be for everyone, including people with type 1 diabetes, pregnant women, lactating women, and eating disorders.
Intermittent fasting is essentially a diet regimen that cycles between brief periods of fasting, with either no food or significant calorie reduction and periods of unrestricted eating. The most popular method is 16/8.
Many religions incorporate fasting, such as Roman Catholics “40-day lent” and Islam with Ramadan. Religious fasting purpose is to be able to relate to the poor and hungry, it also creates self-control over food, and keeps gluten in check. Fasting strengthens self-discipline and allows us the ability to abstain from certain things we desire.
In other early cultures, a fast was often demanded before going to war or as part of a coming of age ritual.
Intermittent fasting promotes the change in body composition through loss of fat mass and weight. It also improves markers of health that are associated with diseases such as blood pressure and cholesterol levels.
Intermittent fasting has been used not only for weight loss but to improve concentration, extend life, prevent Alzheimer's, prevent insulin resistance, and even reverse the entire aging process.
The pituitary gland secretes growth hormone, the growth hormone is sent to the liver, where the liver is triggered to produce the hormone IGF-1, which is an extension of growth hormone. It has the same chemical structure as insulin. If insulin is released in the body by eating, your body will use sugar as fuel. When you fast you will use fat as fuel and some stored sugar. IGF-1 works when you’re not eating and insulin works when you’re eating.
IGF-1 is beneficial because it stimulates cell growth throughout your entire body causes reproduction and regeneration of cells. Helps to build muscle mass and increase strength (1).
It plays an important role in neurogenesis, allowing existing neurons to survive, helps prevent neurodegenerative diseases such as Alzheimer's and Parkinson's disease. Studies on older men show that those with higher levels of this growth factor maintained increased cognitive functioning, especially when it comes to the speed at which the brain processes information (2).
Increased immune function by triggering the production of T-cells in the thymus gland and B-cells in bone marrow, IGFs may help to boost immune function (3).
High levels of IGF-1 have been associated with development, progression, and spreading of a certain type of cancer such as:
Breast Cancer (4)
Prostate Cancer (5)
Lung Cancer (6)
Colorectal Cancer (7)
This is due to the protective effects that growth factor has on cells, it can also strengthen cancer cells, leaving them resistant to the most common treatment methods. But on the contrary too little IGF-1 is bad and you may end up with brittle bones, low muscle mass, heart disease, and reduced vigor.
The key to optimal health is you need periods of high IGF-1 (to build and grow) and periods of low IGF-1 (to repair) this is why intermittent fasting is the best of both these worlds.
Most importantly, when insulin is increased, lipids can’t leave fat cells
The study here shown an increase in fat oxidation during alternate day fasting subjects (8).
Human Growth Hormone is produced in the pituitary gland. It plays a huge role in human development. A deficiency in HGH leads to an increase in body fat, osteopenia (lower bone density), and sarcopenia (lower muscle mass). HGH lasts in your bloodstream for a few minutes and then it gets processed by your liver.
Growth hormone is a counter-regulatory hormone. The highest amount of GH is secreted right before you wake up. It is counter regulatory because it counters insulin. GH promotes lipolysis, have you ever noticed that you are not so hungry after you wake up? That’s because GH is promoting the breakdown of fat so you have energy after you wake up.
Intermittent fasting has shown to increase overall growth hormone. It is increasing due to low glucose levels. Your body needs energy and it wants to grow. When you are fasting you are not getting energy from an outside source and you’re not secreting much insulin, but your body still needs energy. There are multiple mechanisms that provide energy for your cells and secreting GH is one of them. Naturally when you eat you have a drop in GH because your body is getting the increased glucose from an outside source and it is also secreting insulin (10, 11, 12).
Another great aspect about IF is that it increases autophagia. Autophagia is your body getting rid of old damaged cells. Just like with most of these points it is directly related to insulin. One study showed that there was a dramatic decrease in hepatic autophagia with increased insulin. The study showed Hepatic Autophagy Is Suppressed in the Presence of Insulin Resistance and Hyperinsulinemia. Also since you aren’t eating, you are putting your body into starvation mode, our body is very efficient and is able to recycle those old damaged cells.
Since we are on autophagia and you can attribute that to cellular repair let’s talk about telomeres. Our cells replicate a lot, we have millions of cells replicating every day. A telomere is a short sequence of nucleotides found at the end of chromosomes.
During mitosis, a cell is able to reproduce a copy of itself. Due to the nature of the process, the ends of the chromosomes do not completely replicate. Each time our cell replicates it loses a piece of itself, and that part is the telomere. It guards the cells DNA by being cut out little by little.
This extension to the chromosome prevents the loss or damage of genetic DNA. it is hard to get the telomeres back which limits the number of times a cell can divide. Once your telomere is gone your cell is at high risk for mutation so it kills itself.
Some research has shown that IF increases telomere length. The mechanism is not 100% understood but it has something to do with repurposing old cells and promoting the function of telomerase. Ultimately longer telomeres lead to a longer lifespan and shorter telomeres can lead to cancer and other diseases.
Certain cancers that activate telomerase make it hard to treat and fight off cancer. Telomerase is responsible for preventing the shortening of telomeres.
It’s like meditation but for your insides! You don’t become so dependent on food. Starting off is a little rough because you do get hungry. Once you get into a flow you program your body on when it is allowed to eat. You don’t get those random hungry feelings throughout the day, unless you are doing something new like a new intense workout but even then your body adapts.
We both feel that our mind is sharper, less ADHD like. You can focus more on things you have to do and be more productive. A lot of time is devoted to eating, that’s not a bad thing, most people have 4 meals a day with snacks in between. With fasting you have specific times to eat, you’re basically organizing the time you eat into one period of time.
Many times after a big meal we feel sluggish and you don’t get that as much when you fast. You might get it after your first big meal of the day but it's not as drastic as it is when you weren’t fasting. We rarely get them unless we go out for some nice deep dish with butter crust. Sometimes food does tend to slow us down, make our tires, and feel sluggish and depending on what your eating it can happen multiple times a day.
Once you are able to control your eating and food cravings life tends to get easier. It’s easier to accomplish goals and stay on task. Hunger is one of the hardest things to fight and overcome. You get a feeling of success and accomplishment. Your mood gets better and you simply feel happier because fasting has physical and mental benefits.
How long to fast for?
We have a few blogs on intermittent fasting. There is the 5:2 method where you eat healthy for 5 days the restrict your calories to 500 for 2 days. Eat-Stop-Eat is where you fast for 24 hours once or twice a week. Alternate day fasting is where you fast every other day, some versions say you can eat 500 calories on fasting days. Warrior diet is when you fast all day and feast at night, with a 4-hour eating window so you eat one giant meal each day. Our favorite is 16:8, you fast for 16 and eat for 8 hours every day.
You sure can. Just make sure you are eating enough calories for your goals. If you start getting sick, nose bleeds, shakes, headaches, dizziness, or any kind of weird symptoms you didn’t have before stop and go see a doctor.