Everything You Need To Know About Intermittent Fasting

Intermittent fasting is the most popular "diet" out there at the moment — even though it's not, in fact, a diet at all, nor does weight loss have to be at the center of your reason for engaging in it. Intermittent fasting is a way of life, a dieting pattern that involves intermittent fasting either every day or every week.

Some people choose to fast for a few days a week, as in the 5:2 diet, whilst others choose to fast for one meal per day or two meals per day.

Some people choose to fast through breakfast, only eating from 12pm to 8pm, while others fast for two days at a time. Why? And how?

Fasting For Weight Loss

Intermittent fasting can boost the success of your weight loss efforts in a couple of ways. The most obvious way in which intermittent fasting helps you lose weight is simply because fasting causes a calorie deficit, and any calorie deficit will eventually cause weight loss. If you take in fewer calories than your body needs to perform its basic functions, you'll burn calories from your fat stores instead, resulting in weight loss. 

When you eat a meal, there's a decent store of energy readily available in your body from the food you just ate. In the hours following a meal, your body will take energy from that meal instead of from your fat stores. If you've just eaten a carb or sugar-heavy meal, this is especially true - sugar is easier to burn than other sources.

If you fast and work out, your body will also use energy from your fat stores to fuel your work out, again resulting in weight loss.

Fasting For Better Health

A landmark research study by BBC Horizon found that a calorie deficit, or calorie restriction, is also known to improve life expectancy in animals. Intermittent fasting has been found to increase life expectancy in mice, and mounting data shows that it could increase life expectancy in monkeys too - so it's not unreasonable to assume that the data could also apply to humans, too.

More recent research has also found that fasting can reduce the levels of the growth hormone IGF-1. IGF-1 is found in higher quantities when we are young as it's basically what keeps all of our cells in growth mode - but as we get older and reach our full height, this hormone could be dangerous, causing cell mutations that could lead to cancer. High levels of the IGF-1 hormone can be reduced with fasting, according to new research, and this could reduce the risk of cancer and related diseases. People with Laron disease have very low levels of IGF-1 and this means they are very short - but they also seem to be protected against diabetes and cancer. 

What You Need To Know Before Fasting

Although intermittent fasting is known to improve weight loss results - and in some cases, to improve health, it is difficult. If you're used to eating three full meals a day and some snacks to boot, sticking to this new lifestyle is a real challenge. Whilst people are fasting, it's not uncommon for them to feel lethargic, stomach-achingly hungry, grumpy and tired. That's completely normal - if your body is used to eating food at specific times every day and you don't meet those hunger needs, you'll most definitely feel grumpy and hungry!

The initial transition from eating when you want to to restricting your calorie intake and fasting for one meal or a full day is tricky, but once you get past it, according to a recent study, cognitive function and energy levels return to normal within 48 hours. You just have to push through! How long does it take for your body to get used to this new way of life? Many intermittent fasting advocates say that two weeks does the trick.

Read More: Fasting: Pros and Cons

Some people who have followed an intermittent fasting plan have reported side effects, such as:

• severe headaches
• difficulty sleeping
• dehydration
• drowsiness
• irritability
• bad breath
• anxiety and depression

Little is yet known about why people might be experiencing these symptoms because there haven't been enough long-term studies into the effects of intermittent fasting. Some experts believe that these unpleasant symptoms could be due to an increase in cortisol production. Cortisol is the "stress hormone". If you're not eating food when your body thinks you need it, you could become stressed. If you're repeatedly stressed over the course of one day, cortisol builds up in your body - and this can cause things like irritability, anxiety and depression. Other symptoms, such as bad breath, are caused simply because of the calorie deficit. 

It's also really important to speak to your doctor before beginning any intermittent fasting plan, especially if you have blood sugar problems or diabetes. Intermittent fasting can play havoc with your blood sugar levels and if you need them to stay level and stable throughout the day, fasting probably isn't for you. Equally, if you have severe, long-term health complaints like high blood pressure or heart disease, it's really important that you see your doctor before starting any sort of fasting regime. 

However, some people really flourish on intermittent fasting regimes - it totally depends on your health and your body.