The 5:2 diet is not really fasting in the true sense of the word, it is calorie restriction rather than a true fast (although some like me do a water fast on my fast days). It is the intermittent nature of the restriction which by and large prevents your metabolism from going into energy conservation mode. By restricting your food intake for 2 out of 7 days rather than spreading out that restriction over 7 days your body is less likely to go into conservation mode and slow your metabolism down. A tell tail sign is that people complain about being cold or they feel sluggish. This is your body’s way of hanging onto its fat rather than burning it.

With respect to your fast day, eating one meal is better than 2 meals is better than 3 meals is better than snacking throughout the day. Each time you eat your blood glucose will spike and this will cause a spike in insulin. A high basal insulin level means you are storing excess energy as fat rather than tapping into your fat reserves. The foods you choose also impact on your insulin levels. Fats do not affect insulin, protein slightly (whey protein a lot and that’s what they use in all those protein shakes) and simple carbs and sugar cause a big spike. Whole fruits in moderation are OK, never fruit juice or dried fruits.

Hope that helps.

I do see a contradiction here as well.

I tend to agree with the position that the time-gap between meals is what really matters. To eat only healthy food and less quantity is a given constant – this is what every doctor tells us (for the moment let’s relax the question what healthy food actually covers, because the mainstream opinion demonising fat is a major flaw) – so the question at hand remains WHEN exactly to eat that less and healthy food?

I can’t recall exactly which expert(s) cited them, but I remember certain studies showing when certain calories/foods are eaten as many snacks spread throughout the day, or as one, two, or three meals a day, the different eating patterns yielded different impacts on weight-loss.

The research underlying intermittent fasting is the evidence that the mainstream advice ‘reduce calories and exercise more’ does not help, to the contrary, it yields an adverse effect on weight-loss, since it reduces the metabolic rate.

This is exactly why the very idea of intermittent fasting was introduced in the first place and this is why IF (or fasting as such) is the only kind of diet that actually works for those who can’t see results via mere calorie-reduction.

I think the point in this context is the fact that on fast days the allowed 500/600 kcal is such a small amount of food that it counts as “no eating at all” hence it does not really matter when you eat it. On non-fast days however, for weight-loss purpos at least, the 1, 2 or 3 meals a day is better than snacking. In my experience one meal in the evening is the most effective.

Hi Penny, I absolutely love the idea that you brought up.

The other day I ended up with a sort of “milk-fast”, since most of my calorie intake on a recent fast day came from the whole milk that I added to my coffee(s). Then I started wondering if there is such a thing as “milk-fast”, since milk is one of the very best sources of nutrition.

(Note: Based on my research and experience, whole milk is better for fasting than skim milk because even though it is higher in calories, the fat-content reduces the insulin-spike caused by the animal-source protein in the milk.)

What happens if as a woman I have 600 or 550 calories? Why is 500 the magic number?
And suggestions of what to do if you ca’t sleep due to hunger?

Hi Tash,

Remember each of us here is an individual working within what works for us with our personal medical profile, eating style, and lifestyle; we come from all over the world, and none of us are experts as intermittent fasting (IF) is in it’s infancy.

When people come onto the forum they have learnt about IF, many never been on a forum before, and then it can be confusing for people who are totally new to 5:2. 5:2 is one variation of IF, formulated to make IF more do-able by the average person. Other versions of IF all work but are not as do-able by the average person. 5:2 and IF in general works. It normalises weight and improves our health by the effect of the variation of days with calories and days with no or very low calories. As stated, 5:2 is 2 non-consecutive days of fasting. The people on the forum vary greatly. Some are doing straight 5:2 as promoted by Dr M. The forum is not one where the philosophy and moderator is very strict about people only talking about straight 5:2. For various reasons there are people on here doing IF in various ways 5:2, 4:3, alternate day fasting, water fasting on fast days. There are also people who choose to do consecutive fast days(FDs) and multi day fasting for various reasons, that are not 5:2 but allowed on this forum. This is a very encouraging forum where people behave well and support new people and long term ears alike. Many of us have decided to do 5:2 for life because it has been so beneficial to us. We’re also a group of people who have struggled with weight long term, tried various things and finally found what works healthily and actually works. That can make us very gung-ho and enthusiastic about what’s worked for us.

People do IF for various reasons – some weight, some health, some weight and health, but remember each of us is an individual. We know now that what works for 1 person doesn’t work for everyone. There are general patterns where we see groups of people who respond in certain ways e.g. There is a large group of people who find FDs work best for them if they have 2 meals -breakfast and dinner. There is also a large group who have a phenomena we call on here “waking the hunger dragon”, where whatever time in the day they first eat anything their hunger wakes up with a rage. They work best putting off eating. The 2 meal group don’t seem to get this, and. can feel nauseous if they don’t have breakfast however small. The Hunger Dragon Group usually have 1 meal in the evening. Some of them elect to not eat at all on FDs and you will see talk of fluid only or water only fasts.

500/600 calories is a 1/4 of average daily calories of 2000/2400 calories respectively for males/females. We’re not all average. If you’ve read the 5:2 book you’ll see that Dr Mosely gives the 5:2 guidelines as <500/600 cals or <1/4 of your TDEE. There is a calculator on here to work out your TDEE – Total Daily Energy Expenditure. 1/4 of your daily TDEE is more accurate for an individual than the average of 500 cals. Whichever you use, 5:2 will work, as the cals are very restricted on your 2FDs. I strongly suggest you stick to the basic 5:2 guidelines to begin with for a couple of months. Learn the basics first, then you will have some experience of how you personally react and can, if you wish, to start varying things according to your personal goals and circumstances. You’ve already discovered that leaving all your food to the end of the day doesn’t work well for you and your lifestyle needs. Stick to what you’ve worked out works for you on FDs. Have your calories in whatever food and fluids works for you. What it is doesn’t matter so much at this point. You will find you start thinking about food differently and on your nonFDs you will start making healthier choices.

The are also people who are on 5:2 who are here for medical reasons, one of which is high blood sugar, so you will see talk about that more than some other less common medical things. It’s all good. Another group, but certainly not all, find that grains and starchy carbohydrates are very detrimental to their weight loss. I’m one of those and need to compensate with extra B vitamin supplement. We’re also not perfect. Most people still have birthday cake, Christmas, Eid, whatever is their lifestle’s celebrations. 5:2 teaches us how to handle those things over time.

Remember, this is about you, and what works for you. It needs to be sustainable. I suggest, if you haven’t already, read the info for newbies by simcoeluv. It is excellent. Sorry I can’t put the link in, but simcoeluv often turns up on newbie threads to give the link, or you can put info for newbies in the search box.

Congratulations on already working out some of how you react and adjusting accordingly. Some people would have given up, but you didn’t. Well done!

Best wishes to you,
Onwards and Downwards,
Merry,
(Nearly 2 yrs on 5:2, 19kgs down and nearly at maintenance, 5:2 tortoise because of health issue, but on it for life)