Am I the only one who is slightly alarmed by the incredibly low number of calories for non-fasting days being bounced around here?
I remember from the days when I read all about diets that you should never go below about 1500 cals a day – and that only for a short amount of time.
Here I’m reading numbers below that and for the 5 days in between the 500-600 cal days.
Take care people – don’t go radical. You will do yourself more harm than good and it could be outright dangerous for some.

Golly, I love danger!

Only problem Im having is oodles and oodles of energy, I’m bouncing off the ceiling, swiped my son’s beat pill yesterday, surprised I dont have an ASBO, singing loud enough to take the roof off – and dancibg like no-one is watching – at least I hope no-one is! OH did point out I was cruxifying ‘Jerusalam’ when I continued today. Though he thought my Monkees entire hits was quite good.

Dont think Ive hit 1500 calories more than three times in the past three months, I havent become beautiful in the meantime – such a pity – but my hair and skin is blummin’ good, and Im losing weight quite steadily, . Not bad for an old broad who is reaching 60 next year! Between 6-10 a day portions of veggies a day.

Researching and seriously thinking of a longer fast than 36 hours, would love to know if anyone has done one! Not thinking of anything too drastic, a few days is radical enough for me.

Im spot on four months today – Ill leave it go the maintenance crew to chip in how they are doing long term, because the longterm benefits are what is most important about this WOL!!!

Hi Milena–

I have fasted up to 10 days at one time. It was a personal choice and beyond 48 hours I experienced real energy–no hunger–and the best sleep of my life.

It was water only– and I broke it with some yogurt–then very light eating for a couple days (1,000cals spread out over a couple meals)

Right now I am doing 36 hours early in the week –then a 24 hour before the weekend. Omnly 10 lbs from my ideal weight, I do it to free myself from the snare of food– so I can realy think about what I am eating when I do actually sit down for a meal.

Good luck!

Hi

My name’s Rick, I’m a GP and wanted to say this is such a good posting! Top point, well made, excellent communication.

That’s all, really.

Rick

Who are the 2 or 3 people you are discussing? Your comment was 1500 calories was too low, some of us have a TDEE below that, or at least will at target weight.

Although many of us stay within TDEE every day, not many going to 500 every day, though I often have 3 or 4 days a week well under 1000, in addition to fast days under 400, and quite often nothing. But some of us do. Is this radical? How do you know?

Haven’t noticed a lack of self confidence. Though I am beginning to think a lot of what we have been taught about eating is tosh. Breakfast is the most important meal of the day, don’t skip meals, butter is bad for you, eat low fat. I could go on. But if it is dangerous to go below 1500 cals – except for a short amount of time, why have people fasted for centuries, and fasting for hours, days or even longer, might actually be good for you. Now thats radical thinking.

A heartfelt post aimed at reaching out to a couple of people whose posts came across as potentially alarming has turned into a sniper’s field.

I feel saddened that no one else would appear to care about the couple of people it was aimed at or even to consider that what these couple of people are doing could be potentially harmful.

I also feel saddened that several people have reacted as if I am criticizing them. If you do not feel that you are one of the couple of people I was reaching out to, you can just ignore it or post helpful comments. Nastiness gets no one anywhere but in the dumps.

Should you feel the need to reply to this, feel free. However, I will not be following this particular thread any more. It’s a shame though, there were some very good posts and supportive, helpful comments coming out along the way. Thank you very much to those who have been posting such wonderful material and thoughts. I appreciate it.

Hi Kirsten

I certainly wasn’t sniping at you, thought it was an interesting topic, your comment was that you had read somewhere eating below 1500 calories – except for a short time – could be dangerous – I simply put forward the counter argument that 1500 calories was more than the recommended maximum for a lot of people, and that I was experiencing great benefits when eating regularly below this.

You made this comment on a forum with a basis in fasting.

You did not direct the comments at anyone in particular, though in your second comment you referred to some people without naming or talking to them directly. It was not at all clear that your first comment was aimed at anyone in particular.

You commented about ruffling feathers -twice- and then expressed an opinion that some people – still unknown – needed confidence building and needed to accept themselves as they are.

If this was not a criticism, it was certainly a little patronizing.

Nevertheless, I didn’t snipe. I certainly didn’t take anything personally – even though I do fall into ‘that restricted category’.

Sorry to see though that you feel sniped at – or had your feathers ruffled, as you would put it. It was not my intention to upset or offend, but I asked for longtermers to chip in, and one did. With humour too!

Pity to leave now when there is an opportunity to discuss what benefits fasting holds for us all. Such a huge topic, and until recently I might have thought your 1500 calories comment was, if anything, on the low side. And that missing lunch was radical, especially as being a second breakfast hobbit is what brought me here in the first place.

So the least you can do is stay on thread,stand your ground and make your argument, but do it by chatting and speaking directly to people, rather than throwing out comments meant for individuals.
I look forward to chatting with you again soon.

This has been the most effective and easiest diet I’ve ever done. I lost 2 pounds a week (2 stone, and 6 inches of girth, in total) like clockwork until reaching my target, which put me just inside my healthy weight range. On non-fasting days, I ate as much as I felt like and was surprised to find this ranged from only 1600 calories (which is about my BMR)to about 2400 calories a day. (Both this site and the Mayo Clinic give my TDEE as about 2250.) Among other things, I have noticed that my appetite is much less since starting the diet, and sometimes it even feels like a struggle to eat 600 calories on a fasting day (I now do it all in one go at dinner time.) My activity levels also fluctuate quite a bit — tennis and HIIT three times a week, but often quite sedentary on other days. This no doubt accounts for the variations in my appetite, though I haven’t noticed a direct correlation between high activity days and high appetite days — in fact, I have preferred to do my exercise on fasting days as that is when I have felt most energetic (!) and I want to enjoy the benefits of exercising in a fasted state.

After several weeks of maintaining, I am now aiming to lose another 5 pounds, partly to provide more of a cushion, and partly because my cholesterol is still higher than I’d like and I want to see if losing a bit more visceral fat will have an effect. The thing is, I’m starting for the first time to feel drained on fasting days. This raises two questions: (1) could simply this mean that I am having more difficulty drawing energy from fat now that I’ve lost so much of it, and (2) more generally, shouldn’t TDEE and my target calorie intake vary according to how active I am from day to day? In other words, if my average TDEE is 2250, doesn’t this mean that on inactive days my TDEE is actually closer to my BMR, while on very active days it must necessarily exceed 2250?

Hi Ian
Two things:
My understanding is that exercise is more effective on fast days. I know they are the days when I run everywhere and feel 12. 🙂 I’ve been doing 5:2 for 2 1/2 years now and it is unusual for me to run out of energy on fast days even though I eat only 350 cals in the evening and have very little fat on my body now.

If you set your TDEE at the level it will be when you reach your goal weight, and set the activity level to sedentary, you gain maximum benefit from fasting and learn to eat as you will for the rest of your life. So, no, I would not be eating those extra cals if you can manage learning to eat less.
All the best. PVE

To expand a bit, my current pattern is to begin my fast at 11pm or midnight, do tennis and gym around midday the next day, followed by a small portion of complex carbs to replace my glycogen stores, then have a normal dinner. The next day, I do tennis and gym again after midday then break my fast and resume normal eating. This worked fine for a while, but I find I’m running low on energy before dinner on the first full fasting day, though I don’t feel hungry. I think it might be wiser to eat my one meal in the middle of the full fasting day rather than wait till dinner, though this would prevent me from having dinner en famille on a fasting day.

While I enjoy the midnight to midday two days later pattern, which is the least disruptive to my social and family life, I think I may have been overdoing the exercise a bit. I thought perhaps the reason I was running out of steam might be that the generous store of fat around my middle is all gone, I still have 17% body fat, so it seems more likely it is stretching my fasting period a bit too long.

Thanks again for your thoughtful and helpful reply. I want to stress, though, that I only lack energy during part of a fast day (when I go 19 or 20 hours with minimal intake). I never used to lack energy while fasting (quite the opposite), so if insufficient body fat is unlikely to explain the lack of energy, it must be the eating pattern. Rather than add more calories on a fasting day, it makes more sense to rearrange them and have a small lunch and dinner, rather than one big dinner.

I expect I will switch to 6:1 in a week or two when I reach my weight goal, but I still want to avoid any lack of energy on my one fasting day.

So, I’ve lost my extra 5 pounds (a little over 7, actually), but just over half of the loss was muscle mass. I know this from the readings from a state-of-the-art machine at the office of a friend who is a state registered dietitian. Now that I have reached my target weight and body fat (16%), I do not wish to lose more muscle mass by continuing to eat way under my TDEE.

Incidentally, the machine gives me a TDEE of about 2550, as opposed to the 2250 estimate given by the online calculators. I’m not going to worry about the relatively small difference between 2250 and 2550 and am happy to aim for the average of 2400. What I believe I should avoid, though, is eating only 1300 or 1400 calories except on my fasting day (and I’m now doing 6:1 for maintenance).

I am aware that my decreased appetite makes it easy to undereat, but I think it’s important not to let my calorie intake drop so low that I lose more muscle mass. Listening to my body instead of my brain may not have been best after all.

thank you for this post. I am new to 5:2, in my second week and just finished 3rd fast yesterday. I went to the Mayo clinic link and learned that my TDEE is 1800 calories a day, which translates into 450 calories on fast days. This means I consumed 900 calories less the first week, which does not even add up to a pound. This may be why I have still experienced no weight loss, but I did lose 3 inches of stomach fat and my pants fit better. thank you, J23

What does BMR stand for?

I always eat too many calories after my fast days but I eat natural foods rather than processed foods whenever possible and try to have sufficient fibre, fresh vegetables, iron and good oils etc. I count calories on my fast days and otherwise concentrate on nutrition. I find counting calories all the time too difficult to continue in the long term and find it an added complication. So far I am still losing weight but when that stops I will start looking at my TDEE if I want to go lower. I have been on the 5:2 diet for 6 months now and lost two stone.

So..from what you are saying it really isn’t possible that this is the holy grail of dieting where I can fast two days and eat what I like … I.e a bit of cake if I want, eat out in a restaurant etc and not count calories which is what the book says …. so this diet is like any other diet which is based on restriction!?

Tish Tash,

You have to be realistic. There is no such thing as a magical bullet that will cure all your ills while allowing you to do as you please. I don’t think this diet is like other diets. It does allow you to eat what you want on the 5 days if that’s what you want to do. But then don’t expect to achieve the same results as someone that chooses to eat in a more healthy reserved manner. It just cant work like that?? I don’t count calories at all. My one fast day is water only. My six non fast days I don’t count calories but I choose not to eat foods that aren’t good for me. I avoid sugar like the plague. Chocolate no longer holds an interest for me. I do not eat bread, rice potatoes or any carb dense foods.

That’s not to say I don’t have these foods sometimes but there has to be a good reason. A special birthday etc. The book says to eat up to your TDEE on NFD and 500/600 on FD. You don’t have to count calories if you have a sense of how much food 2000 odd calories looks like. Trouble is most people have no idea what 2000 calories looks like. You’d be stunned at how little it really is. So best to count calories to start with until you get a feel for how much 2000 looks like. The one thing I can say is that the longer you do this diet for the more you will tend to gravitate to a healthier eating style. Well for me at least it came naturally, it wasn’t like I was forcing the issue.

Give it a genuine try. It works. If your expecting magic then no it wont work for you. Success doesn’t chase you, you have to chase it.

All
I think some of the point is being lost here. Weightloss is only PART of the benefit of 5:2 (arguably the less significant part). There’s increasing medical evidence that Fasting for 16+ hours has alsorts of cario-metabolic benefits well beyound weight loss. Risk of heart disease; diabetes; cancer; dementia – which are the major killers in western society- all seem to be reduced by fasting. Add to that eating mindfully and healthily; getting sufficent sleep of good quality; moving around a lot and doing some strenght and some high-intensity exercise are additive. In combination these lifestyle choices give us the best chance of living into old age and being happy and healthy while we do. Try googling Blue Zones TED talk for more.

Bottom line: This is about lifestyle choices and let’s not over-concentrate on weight-loss.

Since I started on this, I’ve been reading huge numbers of scientific papers, and it’s clear that while weight loss itself can be as simple as restricting calories, it goes on from there to be much more complex, especially when you include other health aspects. Caloric restriction using IF and a small amount of food (translating to 500cals) extended the lives of mice and did other things too That’s what prompted Krista Varady (originally one of the researchers on longevity) to explore IF using 500 cals with humans, primarily for weight loss. The groups of humans that calorie restrict as a permanent way of life have very good blood tests and blood pressure, but they don’t smoke and drink either. They are not part of a scientific study, though I suspect they are attempting to keep some records, there being scientists among them.

Simco is right in that there are too many variables in human eating and living habits. And nutrition is incredibly hard to study even in a project because of all the many variables. Some of this seems to be responsible for the controversy we’re in over fat (eg earlier researchers didn’t account for the fact that people being studied were eating high carb as well as high fat and they didn’t separate these two items adequately, nor the smoking). The whole issue of calories is complex; for example, take fats: Phinney showed that certain types of fat (short chain, saturated) are used immediately, not stored, while Polyunsaturates are stored if they aren’t needed immediately. If you are eating lots of carbs they will be stored in different places, some where they can be used fast, others for slower use and these last might not be needed if you go on eating lots frequently, so they mount up. But with eating gaps through fasting your body needs to draw on fat stores and can only do so effectively if your insulin has been allowed to subside (eg through no sweet or carby snacks!). So some of that info needs to be added to the notion of what to eat when you aren’t fasting.
Calories are not equal in their physical effects: 100 cals of fats (about 11 grams) won’t spike your blood sugar on its own; 100 cals of sugar (about 25 grams) will, and insulin will be released to get it out of the blood into storage. It gets more complex when you look at mixing these things, but part of the problem is that sugar we often eat on its own or else with another carbohydrate, a double whammy as the body treats them as much the same. While insulin is high, fat won’t be taken from fat cells for use in the body, so you’ll start feeling hungry again instead, maybe with carb cravings too. So have your burger, but give the bun to the birds!

What about composting the bun? Will this result in obese worms? 😊 P

Being apparently well-adapted to something and that something being good for are aren’t necessarily the same thing of course… Hence the obesity epidemic in humans….

True!

☺