“Intermittent fasting” was the number one diet-related Google search of 2019. You’ve probably heard about it and it’s likely you know somebody that does it, but do you know what it is and why it’s so popular?
What is intermittent fasting?
It’s an eating schedule that focuses on giving your body an extended period of fasting between times of eating (feeding). At any time over the course of day or night, your body is in a fed or fasted state. In the fed state, your body is digesting food and your insulin levels are higher. When you are in a fasted state (usually around 8 to 12 hours after your body has finished digesting food), your insulin levels drop and your body begins the switch to utilising your fat stores for energy, as well as diverting energy to cellular clean-up processes.
It’s what we’re designed to do
Intermittent fasting is what are bodies are naturally designed to do. In times gone by when food wasn’t available all around the clock, we would spend more time across a 24 hour period in a fasted state than a fed state. Back in hunter-gatherer times, often food simply ran away and we couldn’t catch it! We could go days without food and we would eat in abundance when it was available. Our bodies have evolved to deal with this and are designed to store away food energy, so that it’s available to us in times of no food. The issue we have now is that we never have no food!
It’s all about insulin
Not that long ago, eating between meals was frowned upon and most people sat down only at the table to eat. Nowadays we are prone to eating around the clock and fasting less. This is because it has become normal to eat from the moment we wake up until the moment we go to bed, as well as snacking in between meals. As a result, our bodies have undergone a significant biochemical change, specifically relating to insulin and the hormones that regulate hunger and satiation. High insulin leads to excess hunger, excess cravings, obesity and diabetes, as well as being the driver behind an array of degenerative health conditions.
How long can you fast for?
Fasts can range from 12 hours to 3 months or more! You might choose to fast once a week, once a month or once a year. You may decide to do a 24 hour fast each week, or a 7 day fast twice a year. A popular way to fast regularly is eat your first meal of the day later and finish your dinner earlier, keeping you in a fasted state longer than a fed state, in each 24 hour period. For example the 16/8 schedule where you eat in an 8 hour window and fast for 16 hours, e.g. first meal at 12pm, last meal at 8pm.
Keto and intermittent fasting
If you don’t eat for many hours your body will naturally go into ketosis to start burning fat for fuel instead of glucose. If you’re looking to start a ketogenic way of eating, fasting can be a powerful way to enter ketosis at the start. It’s also a great way to boost the power of a ketogenic diet over a 24 hour period. When you eat less carbs, you have less insulin, you burn more fat and your hunger is regulated. You simply cannot overeat on a ketogenic diet because the body isn’t constantly crying out to be topped up with glucose. Many followers of a ketogenic diet use intermittent fasting to boost the effects of ketosis, especially for weight loss.
Benefits of fasting
Reduced insulin. When insulin is reduced, cravings go away, hunger is regulated and fat stores can be accessed. Insulin sensitivity is improved and blood sugar levels are lowered.
Reduced inflammation. Lowering insulin and the body’s sugar load lowers inflammation.
Healing. When you give your body a long break between meals it gives your digestive system a chance to rest, allowing your body to switch to a healing mode, whereby it works on repair and cellular cleaning (autophagy). This is the reason why fasting is used for prevention of illness and anti-ageing.
Weight loss. When in a fasted state the body will switch to fat burning. Insulin creates fat storage and is the key that locks away stored fat. Insulin has to be low for the lock to open and for fat stores to be used. Weight loss is a hormonal balancing act, not a caloric balancing act.
It’s simple. Most intermittent fasters skip breakfast, making this eating schedule very simple. The benefits are huge for such a small step.
Article by Jo Rowkins, nutritional therapist at Awakening Health.
If you’d like to get started on a fasting schedule, whether that’s a daily one like the 16/8, or longer fasts such as 3-5 days (or more with some supervision), or you’d like to use a fast to kick-start a ketogenic diet, please get in touch to see how I can help you.