Intermittent fasting - What is it and can it help you lose weight?
If you've either heard through the grapevine or have come across the term "intermittent fasting" online or in a newspaper, you may be tempted to see if it can help you lose weight. Firstly, intermittent fasting isn't a "diet" in the traditional sense. Whereas dieting implies restricting the types of food and amount of calories you eat, intermittent fasting is more of a timed approach to eating whatever you want but restricting when you can eat it.
Although not suitable for everyone, there are several different intermittent fasting regimes to choose from so we'll take a look at a few of the more popular ones in this post:
- The 16/8 method:- This means only eating during an 8-hour timeframe each day e.g. 12 noon to 8pm and fasting for the other 16 hours
- Eat-Stop-Eat method:- This is similar to the 5:2 diet below, although you fast completely for 2 (non-consecutive) days of the week and eat normally for the other 5 days.
- The 5:2 diet:- Although also a type of diet, this involves limiting your intake to around 500 calories for 2 days each week whilst eating normally for the other 5 days.
You'll no doubt find variations of the above methods (e.g. the Warrior Diet or Alternate Day Fasting) but the three above provide the basic framework of what intermittent fasting entails. It's also worth pointing out that if you do decide to opt for any form of intermittent fasting, it's recommended that when you do eat, you eat a broad range of foods; not just the stuff you enjoy bingeing on such as junk food, chocolate, crisps, etc.
In the spotlight - The '16/8' and 'Eat-Stop-Eat' methods
Since both the 16/8 and Eat-Stop-Eat (ESE) methods both fit the definition of intermittent fasting fairly well, let's take a closer look at both.
16/8 - To summarise, the 16/8 method involves restricting your intake of calories to 8 hours each day while fasting for the other 16. If we take midday to 8pm as the classic example, this means that when the clock strikes noon (or thereabouts), you can begin eating. Generally speaking, your body will be able to cope with 2 or 3 decent sized meals within 8 hours so you're free to prepare a decent-sized lunch to get you started. Whether or not you're a meat/fish/dairy eater, you can pick the meals that you enjoy the most. Unlike traditional dieting, you don't need to worry about low calorie 'this or that' and can eat the stuff you really like.
You may choose a hearty pasta meal or just a well-stocked sandwich with your favourite ingredients to start the day with, followed by another meal or snack later in the afternoon before rounding it off with a decent evening meal shortly before 8pm. If this sounds appealing, bear in mind there are a few pros and cons. For instance, this regime may suit you well if you're one of those people who don't tend to eat breakfast as part of your daily routine. However, you'll need to bear in mind that fasting in the morning also involves avoiding drinks with calories in. This means you'll be limited to things like water, black coffee, black tea or zero-calorie drinks... all with no sugar. On the plus side, if you go to bed fairly early or don't tend to eat much after 8pm anyway, then as your sleeping hours tick by, they're also part of your fast too.
Two important points to note are that this type of fasting won't help you lose weight if you fill your day with junk food or try to eat as much as you can during the 8-hour window. Also, the timing can vary depending on your sex. For men, fasting for 16 hours each day is the norm but for women, this can be reduced to 14 or 15 hours whilst still achieving similar results.
Eat-Stop-Eat - Quite simply, Eat-Stop-Eat involves fasting for either 1 or 2 days of the week. There's no doubt that this method sounds tough as it's not easy to go a whole 24 hours without any calories at all. For example, if you're going for two days in any one week, you may decide to have your last meal at 8pm on a Monday, meaning you can't have another meal or snack until 8pm on Tuesday. Again, this also means avoiding drinks with calories in too. You can repeat the whole process a few days later if you feel you've coped well with a 24-hour fast.
Depending on your personal eating habits, you may prefer to begin the fast at 8am if you're the sort of person that likes to get a good breakfast before the day begins - The result is essentially the same regardless of what time of day you choose to start the fast.
Does intermittent fasting actually work?
To answer this very pertinent question, let's see what the NHS have to say on the matter. According to this post from 2018 on the NHS website which delves into an alternative to the 5:2 diet, the 16/8 fasting regime did show a modest decrease in weight and BMI for those that took part. Admittedly, the study was conducted with a fairly small number of participants but nevertheless, the results appear encouraging. We do suggest taking a look at the NHS article linked above as it contains additional health information if you're considering intermittent fasting in one form or another. In particular, it notes:
"People who have a problem with their cholesterol levels, blood pressure, diabetes or heart health should always consult their GP before starting a fasting-style diet."
Whilst there may be some potential health benefits when fasting intermittently, you should always discuss your plans with your GP first, even if you don't suffer from any of the conditions mentioned above. If the idea doesn't appeal to you or it's something you don't feel confident trying, we may still be able to help you at our medically supervised weight loss clinic. Either give us a call or send us an email to find out more.