Here's Your NTK On Intermittent Fasting
The Debrief: No cayenne pepper diet here, thank you.
I do not believe in diets. Surviving on Beyoncé’s cayenne pepper, lemon juice and maple syrup concoction is my idea of hell. No carb diet? GTFO. And you'd have to pay me (a lot) to go on a juicing diet.
But when I started to learn about intermittend fasting (IF), I was quite intrigued, mainly by the fact that it’s not a diet but a pattern of eating: rather than ‘I can’t eat that plate of pasta’ I can think, ‘I can eat that plate of pasta but at a certain time’, although that doesn't mean it's a free pass to stuff your face with fast food (I know, I'm upset about that too).
I’ve been trying it for a couple of weeks now (the 16:8 version which we'll talk about in a bit) because I'm interested to see what happens. This obviously isn't enough time to wax lyrical about any groundbreaking results, but what I can say is that I've found it pretty easy to adapt my eating habits. And I'm all about an easy life, me.
This is by no means a ‘hey guys, you should all do this right now what are you doing with your life’ type thing, but a way to answer the main questions about it (for me, as well as you). There is so much information out there, I’m exhausted even thinking about it, so do your research and find out what works for you (if anything). One great source is James Clear who has written extensively about it, nutritional consultant Leangains and The Fast Diet.
What is intermittent fasting?
Very simply, IF involves not eating (fasting) for extended periods of time. The amount of time you fast for, how often and when is totally dependant on the approach you choose, and your apporach will depend on what works for you and your lifestyle.
What types of intermittent fasting are there?
There are lots of different options, but the two most common are probably 5:2 and 16:8, so let’s talk about them.
You’ve probably heard about the 5:2 diet. This involves eating ‘normally’ for five days of the week, but restricting your calorie intake to roughly 500 on the other two days. Back in 2012 Dr Michael Mossley was in a BBC documtentary all about it, and his results were really positive.
The 16:8 approach (spearheaded by Leangains) requires fasting for 16 hours of your day, with an eight hour window during which you eat your meals. For example, if you start eating at midday, you'd have your last meal by 8pm.
How does intermittent fasting work?
Really basically: you’re probably going to consume less calories. Sports Dietician and Nutritionist and British Dietetic Association spokesperson, Sharmain Davis, told me that 'If you lose weight, it's because you ate less energy because it’s hard to eat as much as you would in an 8 hour period than say a 12 hour period, which people normally do. You just don’t have the time.'
‘Body composition change and change in body weight is equivalent in intermittent fasting and general calorie restriction, so neither is better or worse,’ she went on. Ultimately, it comes down to what suits you.
However, there is a side effect of IF that could help its success. ‘The only thing that’s superior when it comes to intermittent fasting is that hunger seems to be suppressed a little bit more. That didn’t translate into better body composition results but some people don’t want to feel hungry, which they might do on a general calorie restriction diet, so that might be more motivating for people.’
That said, fasting also means you’re guaranteed to enter a controlled state of ketosis daily. But what the hell is ketosis? ‘During your fasting state, after about 12 hours – although this will vary from person to person – blood sugar and insulin levels drop to their lowest point which force the body into a state of ketosis. This release ketones from fat stores into the bloodstream which are used as energy in a similar way as glucose’ Ollie, personal trainer and co-founder of 3Dburn, explained.
Will intermittent fasting slow down my metabolism?
Sharmain was quite clear on this: ‘No that whole "starvation mode", and metabolic damage is a bit of a myth.’ Dr Mossley has dispelled this 'myth' too, explaining how only very prolonged periods of going without food would actually make the body go into starvation mode and a recent study showed how short-term starvation actually increased metabolic rate.
Can intermittent fasting affect a woman’s fertility?
This would only happen in very extreme cases of energy restriction, i.e. not in IF, and can be something that affects female athletes if they’re not meeting their energy needs. ‘It’s a chronic state of undernutrition really, everyday for a long period of time which isn’t the same as intermittent fasting - that’s not chronic, it’s a few days a week,’ Sharmain explained.
What are the positive effects of intermittent fasting?
Weight loss is an obvious one as well as the flexibility but on top of that, research on animals has shown a variety of benefits such as improved brain function, extended lie span and reduced risk of cancer, although more studies on human are required. People who do it often report increased energy and focus, too – something which, weirdly, I experienced on the very first day of fasting, but is yet to be a regular thing for me.
‘There is an adaptation to fasting that I think is very healthy, although it's possible that not everyone will adapt in the same way. Before I started fasting, going without food for a day, or even for several hours, would lead me to feel nervous but tired, just a little irritable and not terribly productive. Now, I feel pretty much the same on fast days as other days. I am just as alert, just as active and just as engaged.’ Steve Mount, who’s been practising IF for 12 years, told me.
Can you exercise when you’re doing intermittent fasting?
You can go about your exercise routine as usual but be realistic - you wouldn’t suddenly take on a marathon when you haven’t eaten for 24 hours. ‘I’d advise exercising near when you’re going to break the fast so you can eat shortly after, but it’s not essential,’ Ollie told me. ‘You may feel a little weak for the first two weeks, but energy levels seem to rise as the body adjusts.’ Steve reported no affect on his usual fitness routine, ‘I run for exercise, and my pace is no different when I'm fasting than when I'm not.’ If you choose to fast for whole days, it could be that you choose to do your exercise on the days when you’re eating ‘normally’.
Will I lose muscle during intermittent fasting?
‘There’s not been a lot of research in terms of intermittent fasting being successful in terms of gaining muscle, but has been shown in helping retain muscle,’ Sharmain told me. ‘You won’t burn muscle unless you are doing long periods of cardio, but that’s the same whether you’re fasting or not with those kinds of sessions,’ Ollie explained.
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