Fasting is something that is so simple but so misunderstood. Fasting is the period between food intake, though really you are only considered to be “fasting” if the time between food intake is longer than “normal”.
Our first meal of the day is considered to break the overnight fast – hence the name “breakfast”.
Periods of fasting have the following benefits:
- Reduces the level of the insulin hormone which is a major pillar for the low-carb diet.
- It can help you lose weight.
- It can help you switch away from burning carbohydrate as fuel and into fat burning mode.
- By not taking in nutrients, you enable your body to switch out of “growth mode” and into “maintenance mode”. Spending more time in maintenance mode is important for your health and longevity.
- It can help prevent cancer by starving early cancerous growths of their primary fuel (glucose). Cancerous cells can also be destroyed by the process of “autophagy” that really kicks in when the body in in “maintenance mode”.
Some points that we consider important about fasting:
- If you eat food while you are “fasting” then you are not fasting. Seems simple, but many authors promote fasts where you continue to eat some food.
- Fasting does not reduce your metabolic rate. In fact fasting increases your metabolic rate. This is unlike the calorie-reduced diet, that is touted as the solution to the obesity, which does reduce metabolic rate.
- Fasting is not the same as starving. Fasting is a period where you switch the body’s energy supply to its own stored energy reserves (mostly in body fat). It is only when the body’s energy reserves are depleted that starvation begins; and this can be several weeks or a few months for a normal healthy person or even longer for an overweight or obese person.
- Fasting will not make you die. You see so many survivor stories where someone heroically went a week with out food and you believe that they cheated death. The fact is that you can go a very, very long time before you eventually starve to death.
- Breaking a long fast the wrong way can make you die – read about refeeding syndrome below.
- Lack of water is something that will make you die quickly. Fasting does not mean that you reduce water intake – you should always consume as much water as you need.
- Being fat-adapted through a low-carbohydrate diet makes fasting a lot, lot easier to do.
How to fast
There are lots of ways to “fast” and some are easier than others. Just remember that eating during a fast does not count as fasting!
We recommend that you visit Dr Jason Fung’s page (see our websites page) and search for his articles on fasting. Dr Fung has years of clinical experience using fasting as a therapy for his sick and obese patients.
What we recommend
We recommend that you should start with something called “Intermittent Fasting”. It really comes down to moving breakfast to later in the day. You should combine this with meal elimination:
- Don’t eat before breakfast – water and non-caloric beverages only.
- Eat ‘breakfast’ around lunchtime.
- Skip lunch.
- Eat dinner around 5-6pm.
- Don’t eat after dinner – water and non-caloric beverages only.
- On days when you don’t feel particularly hungry, make dinner your only meal of the day.
- Don’t eat to try to make up for missed meals – just eat what you need to.
As well as the major health benefits of fasting, it also helps significantly in weight loss and to help you transition to a fat-burning metabolism.
Caution – Refeeding Syndrome
If you undertake a longer fast of more than a few days, you need to exercise caution when breaking the fast to ensure that Insulin remains low otherwise you could get very sick or even die due to “refeeding syndrome”.
Raised Insulin during refeeding results in increased glycogen, fat and protein synthesis which requires phosphorus, magnesium and potassium. As your body’s store of these minerals can be depleted by long periods of fasting, they can quickly be consumed resulting in low concentrations of these essential minerals in the blood. The results can be heart failure, coma and even death.
It is important to break a long fast slowly (less than 50% calories on first day) and also ensure that you have a good supply of minerals (magnesium, potassium, sodium) and vitamins (esp B1, B-complex). Take a few days to build back to your normal caloric requirements and keep your intake of carbohydrates low.