The Hard & Fast Truth of Intermittent Fasting
One weight loss method that has skyrocketed to popularity in recent years is intermittent fasting.
It involves eating during shorter, set timeframes and then leaving a longer window until you eat again.
There are different methods you can follow, but all help you eat less calories, and are therefore useful when it comes to losing weight.
Plus, there are more health benefits you may be unaware of – including improved cardiovascular health and reduced insulin resistance.1
Sound good? Let’s shed some light on intermittent fasting for weight loss.
What is intermittent fasting?
Intermittent fasting is where you cycle between periods of eating and fasting. It’s not technically a diet, rather, a set pattern of eating.
There are a couple different methods you can try:
This is the most common method, but bear in mind that doesn’t mean it’s suitable for everyone. You need to find what works best for you, not anyone else.
The 16/8 method involves you eating your meals and snacks during an eight hour window, then leaving it 16 hours until you eat again.
As an example, you could start eating at 12pm, have your last meal at 8pm – and then not eat again until 12pm the following day.2 This could mean skipping breakfast altogether, or simply having it later than usual.
But, how you do it is entirely up to you! There are no set rules here, every individual and their bodies are different.
For example, some of us can’t go without our morning porridge so would rather their eating window was earlier in the day. Meanwhile, those among us who can’t stomach breakfast find waiting to eat until later much easier.
Another method is ‘Eat Stop Eat’, which involves a 24-hour fast 1 or two days a week.3 For example, you could stop eating after dinner one night and not eat until dinner the following day.
It’s important to note this isn’t for everyone, many of us would find this very difficult. If you’d rather do 14-16 hours, that’s totally fine. It’s important to listen to your body and do what feels right for you.
Alternate day fasting
This approach to intermittent fasting is where you fast one day and then eat what you want the next day.4 You’re allowed water, zero-calorie drinks and black coffee during fasting periods.
If that doesn’t float your boat, there is a modified version which is more popular with some people. It’s where you eat 500 calories on fasting days, then eat normally on the other days. Both methods can lead to weight loss.
You’ve likely heard of the 5:2 diet, otherwise known as the aptly named ‘Fast Diet’.5 It’s where you restrict your calories to 500-600 two days a week, but eat normally on the other days.
While it’s known as a ‘diet’ it doesn’t prescribe set foods or limit ones you can eat, it’s only about caloric intake. So, it’s more of a lifestyle change or eating pattern.
How it works is that for two days a week (any two of your choice), women eat only 500 calories and men eat 600. Then, for the other five days, you eat a healthy balanced diet.
If you’ve got a spontaneous side, you’re in luck. Another option is to not follow a plan altogether, but to spontaneously skip meals, such as breakfast one day, or dinner the next.
This can help you eat significantly less calories and aid in your weight loss journey.
The Warrior Diet
Fancy yourself a warrior? This approach might be the one for you.
This weight loss plan doesn’t require complete fasting, rather, you eat small amounts of food (normally fruit and veg) for 20 hours, and then have a one large meal.6 You can eat what you like at night during this four hour eating window.
It’s based on the eating patterns of ancient warriors, who ate very little during the day – but feasted at night,7
However, it’s important to note this diet hasn’t been studied scientifically. While intermittent fasting itself has been thoroughly researched and has proven health benefits, the Warrior Diet itself doesn’t.
The intermittent fasting rulebook
The good thing is that intermittent fasting is flexible, so you can tailor it to suit you. However, there are some general ‘rules’ to follow:
- Only water, black coffee and some zero-calorie drinks are allowed during fasting periods. Any food will take you out of the fasting state
- ‘Eating what you like’ when not fasting doesn’t mean eating large amounts of junk food (unfortunately!) it’s important to eat a normal balanced diet – you don’t have to be restrictive here
- It’s important to remember that fasting isn’t magic. If you’re still eating more calories than you burn, it’s likely you won’t lose weight
- You should still do exercise to lose weight, don’t rely on fasting alone
Intermittent fasting for fat loss: how it works
You might be wondering what this all has to do with fat and weight loss.
On the surface, intermittent fasting helps you eat less: fewer meals often result in fewer calories. That’s the simple answer. Unless you overcompensate when you do eat, of course!
Reduced insulin levels
For some people, it lowers insulin levels, which facilitates weight loss.
Insulin controls blood sugar management, and reduced levels of this have been shown to aid in fat burning and weight loss.8 High levels of insulin have been linked to a number of health conditions, including heart disease.
If that wasn’t enough, fasting assists in weight loss by boosting metabolic rate, helping us burn more calories throughout the day.
It does this by boosting the production of Human Growth Hormone (HGH) which increase the breakdown of body fat9 and improves metabolism.
Reduced body fat
The fact that intermittent fasting targets fat loss as well as weight loss is just one reason why it’s hugely popular. Having excess fat, particularly belly fat, can be extremely harmful and is widely known as the most dangerous type of fat.10 However, intermittent fasting has helped many lose it in a sustainable, healthy way.
Benefits of fasting
It’s not all about weight loss! Many incorporate fasting as part of their everyday life to help improve general health.
The good news is that fasting has a number of health benefits and is practiced widely across the world, for example in many religions.
Some of the health benefits include:
- Decrease levels of inflammation associated with illnesses such as heart disease11
- Improves the body’s ability to manage inflammation12
- Reduces insulin resistance, improving blood sugar control
- Reduces the risk of illnesses such as Alzheimer’s by improving brain function
- Improves blood pressure and cholesterol levels, aiding heart health
- Increases growth hormone secretion which promotes muscle gain
- Could delay aging
- Might help to prevent certain cancers
- Defends against depression13
- The list goes on…