Intermittent fasting diets seem to be the ultimate answer to weight problems, health issues and can even delay ageing. Interested? Here is everything you need to know to get started.
What is intermittent fasting?
Fasting diets were created by the monks in the middle ages. Intermittent fasting (IM) involves slashing your calories on one or more days each week. Dieters typically eat 500 calories (600 for men) on the days when they’re fasting and eat whatever they want on the other days. Studies show that people following the diet experience healthy, sustained weight loss without feeling deprived. It may sound faddish but it’s actually scientifically proven and has significant health benefits other than fat burning. Very popular with both men and women, and celebrities include Hugh Fearnley-Whittingstall, Beyonce and actor Hugh Jackman, this diet looks set to continue its popularity into 2014.
There are several versions of intermittent fasting diets. The 5:2 diet or “Fast Diet” by Dr. Michael Moseley, is the original and most popular. As the name implies, you fast for two days each week, and eat your normal diet for the other days. Other versions include the Every-Other-Day-Diet which requires you to have 4 fasting days, and the stricter ‘Alternate Day’ diet which is one day on, one day off. Whichever ratio of days you follow, the benefits of intermittent fasting remain the same.
What are the health benefits?
Many people follow an intermittent fasting diet in order to lose weight, roughly 1-2lb each week, depending on how many days you fast. Research shows that the diet burns fat more effectively and permanently than other diets. This is because it restricts overall calorie intake, reduces blood glucose and insulin levels, preserves muscle tissue and maintains a healthy metabolism. It’s also easier to stick to than other diets because you only have to deprive yourself for one day before returning to normal the next.
Although many overweight people follow the fasting diet, losing weight could almost be considered a side effect of the diet. Significant health benefits also include reduced inflammation, lower blood pressure, improved brain function and a generally protective effect on the brain and cardiovascular system. How does this all happen? Restricting food intake appears to send our cells into survival mode making them more efficient, with increased resistance to stress and damage.
Increased longevity is another highly celebrated benefit. It appears that dietary restriction extends lifespan by reducing the amount of a hormone called insulin-like growth factor 1 (IGF-1). Fasting also appears to change our body to ‘repair’ mode rather than ‘growth’ mode. This delays the onset of several age-related diseases such as Alzheimer’s, diabetes and heart disease.
And don’t forget the lifestyle benefits of simply having some days free from thinking about and preparing nutritionally-balanced food (perhaps a welcome break for a nation increasingly obsessed with diets and cookery).
What should I do on my fasting days?
Try to stay as active as possible. If you sit around slothfully you will be more likely to think about food and give in to your cravings. Many people choose their busy days as fasting days for this reason. If you’re not at work you could take a walk, bike ride, do some housework, read a book or see friends. You can even go the gym. In fact, studies show that people who exercise on their fasting days burn more fat. It might be too much to complete any endurance events like a marathon though! Just aim to keep your body and mind occupied and you won’t think about food so much.
What will happen on my fasting days?
Don’t expect it to be easy at first. You will feel hungry, but this is quite natural and the feeling will pass. You might feel grumpy, tired, have some stomach discomfort, feel shaky or have headaches. But once you’ve done your first few fasts these side effects will lessen and you will start to feel good.
What should I eat and drink on my fasting days?
You should drink as much liquid as possible. This will give the illusion of a full stomach, and keep hunger pangs at bay. Water and herb tea is good, but black tea and coffee are also acceptable, even with milk. You could have alcohol but it will count as calories and will go to your head quickly if you are hungry.
For the fasting days you can eat when you want. However, you should focus on minimum calories, maximum protein and fibre. This will keep you feeling full and energized. It’s best to avoid foods which are refined carbs such as white bread and potatoes because these will raise your blood sugar levels and start cravings! Good ideas include vegetable soups, chicken and fish meals. Filling winter stews are also great this time of year. Many people choose to eat breakfast and dinner only, but snacks are perfectly acceptable. Popular options include vegetable sticks, fruit and raw almonds.
Let us know how you get on!
I have followed 5.2 (or 4.3) since last April, with breaks in August for holidays, and over Christmas. I have lost 3 stone, with minimal effort. It is not as hard as it may at first appear. I feel very well, have less achey joints (reduced inflammation?), and it costs me nothing - in fact i save money becuse I consume less on fast days. Approaching my target I am now considering maintenence - I have not been a yo yo dieter. I have found running fasted works fine - I perhaps get heavy legs sooner, but I can tell myself I am burning fat, and keep going!
Carl, fasting diets have been around for centuries, but there's no doubt Dr. Michael Mosely's programme and diet book is what has made intermittent fasting so popular recently. His book is certainly the first one to make the public really aware of fasting benefits. It's almost certainly got the most up to date scientific research in it too.
As much as I enjoyed the book, the following statement from the post is clearly nonsensical. "The 5:2 diet or â€œFast Dietâ€ by Dr. Michael Moseley, is the original and most popular." Intermittent Fasting is the oldest diet in the world so there is nothing new in using the benefits of fasting for better health. What is new is our understanding of how and why fasting works. Ori Hofmekler was blazing the fasting trail 10 or so years ago with the Warrior Diet so the modern trend for fasting and IF owes much to his work in my opinion. Better researched pieces in future please!
Elliot, not sure cavemen needed to fast as i doubt weight was at the top of their agenda, but nicely put all the same....
I am not a caveman. Therefore I do not need to fast.
Fasting diets seem great for those who need to lose weight. Unfortunttely, those of us who are already slim and don't want to lose more pounds might end up getting very skinny if we followed a fasting diets. So we can't reap the other benefits, unless we completely stuff ourselves on our 'on' days!
Interesting stuff on the biochemistry of fasting - thanks Ray. I get the anti-ageing angle. But what about fasting and training? Can we still build up strength and stamina over fast periods, or is fasting only something to do during times of relative inactivity?
I don't know about buying into it as a way of life, but I find a day or two of fasting is a great way to get back on track after a little too much indulgence. It seems to provide a sort of recovery period.
I've just finished an MSc in nutrition and have included some of the science behind calorie restriction/intermittent fasting in my dissertation. To clear out inefficient components of our cells, we need calories to drop below a certain level to trigger their digestion. If we never let calorie intake drop below a certain threshold, then our cells become more and more inefficient as we age, as the cellular 'house keeping' never gets done. For those interested in the science, look up AMPK, mTOR, autophagy, mitophagy and calorie restriction. Ray
I've altered my own diet to the one day off, one day on version of this for well over a year. After watching the program where Michael Moseley first encountered the idea. It's based off good scientific research. I can vouch that it certainly helps with the control of weight but it certainly is not for everyone. I can do it because I know that tomorrow I can eat and that is good enough for me. I've been eating like this while doing quite active things such as fell walking, Hot yoga, swimming etc. and have been fine as I've still get the reserves from the day before. Quite how people make money out of this is amazing, it is a very simple concept, you don't need a book longer than a single A5 page.
I've read quite a bit about this diet and the main difference it seems to me is that it's getting good PR because 'it's natural for our bodies to fast because that's what we did in old days when food was in short supply, like the cavemen'. So if it's natural for the body to fast then it's ok? I'm not sure this is the case, i think the body can cope with fasting but that's very different than saying it's good for you. I tend to think when my body tells me i'm hungry i should eat! It's what i eat and how active I am that determines how much weight i gain or lose... Fair play though, they've worked the PR well on this one.
I agree with Marium, if you can shed that much weight in a week then it's worth a try. Being miserable is a state of mind. If you pick the right foods I think 'fast days' could be manageable
I fast every day, between meals. I have a 40% failure rate (excluding bread, because bread is not really food and has the same nutritional impact as air, so I don't count that). I also find that fasting is much easier if you drink very bulky drinks, like chicken noodle smoothies. (Drinks also do not count). I have not lost weight yet.
Worth giving it a try to see if it work, loosing 1-2lb a week - yeah I would be happy with that!
Well, if Beyonce does it...
This is just one of those fads that hits the middle classes from time to time, isn't it? And mostly women at that. Can't really see a working man going in for this nonsense.
Whoever came up with this is making a fortune, as has everyone who's come up with a faddy diet. It's just Daily Mail fodder for those who aren't sure how to eat sensibly and then everyone thinks it's a great idea when it's really not.
I have to say I'm sceptical about this one. I can just about understand why people would want to detox for a few days, but to fast for two days for a prolonged time is just crazy to me. I guess I just love my food too much, and when I'm working out I have to say I wouldn't cope. I'm with Derek when he says it just doesn't fit in with a training programme.
Can't see how fasting fits in with an intense training regime. When I've got a cycling race coming up, the last thing I need is to starve myself!
I've been doing intermittent fasting for years, not just for health reasons but because of the mental and spiritual clarity it brings. Your mindset is crucial. If you do it in the spirit of nurturing yourself and taking care of your body and mind, then there's no reason why you should be "hell to be with" because you'll be feeling positive about what you're doing.