The FastDay Forum

Hello everybody I'm a new 5:2 er and am I'm on my 2nd fast day( going ok.) I have significant (4stone) weight to lose and think I've found a realistic long term plan with the 5:2 way of life.
My question is there are a lot of variations around and there was a book called UpDay DownDay by James Johnson which also is 5:2 but there is a 2 week induction where you have 20% of your calories on fast days, and after the 2 weeks you can increase your fast day calories up to 35% of the calories of your regular days. I really like 5:2 but would be delighted if I could eat more on fast days whist getting all the health benefits ( I accept there would be a slower weight loss)-does anybody know more.~ many thanks in advance

[carorees]

The Johnson UDDD is in fact a variation in alternate day fasting so that's 3 or 4 fast days per week, which is why you can get away with more calories on the fast days. Also the up day is not the full total daily calorie allowance so you would get a significant calorie reduction over the week.

The proposed additional health benefits over weight loss that come with doing 5:2 involve having as few calories as possible on the fast days. Dr M felt that a complete fast would be too hard for most people so he chose 25% of normal daily requirements as the limit.

So the answer to your query is that if you increase your fast day calories to 35% you need to reduce your feed day calories or you will not lose weight. Also if you are going to increase your fast day calories you really need to do a 24 hour fast before eating them if you want the extra health benefits.

That's the theory anyway. No scientific proof exists for any of these ideas so far.

Many thanks Carorees- thought it was too good to be true! Lol! I think the 5:2 is the simpler, painless version- thank you for the quick reply*

Hello again caroress- do you think if I did 3 24hr fast days (6pm-6pm) on Mon, Wed, and Friday I would get the same benefits as 2 of the the 36 hr fast days. I can do the fast days as they are ( just about) but would like a shorter fast. But I'm very keen on keeping optimal health benefits? Many thanks in advance for your advice~

Hi fabby2013,

Caroline could give a better answer but I think the short one is: no one really knows, but those at the forefront of the research (esp. Dr Longo and Dr Mattson) would advocate longer periods of total or near-total fast to maximise the benefits, making 2 x 36 hour probably better than 3 x 24 hour. How total should the fast be during the period? That's another question, but as Caroline has said, Dr Mosley's 5:2 formula is a kind of compromise based on what he reckoned (rightly) most of us can face!

Many thanks for your reply, I have been eating 3 tiny meals plus tea (with milk) all day on my fast days so I'm not really getting the full fast benefits that could be gained I suspect. I really want the health benefits more than fast weight loss so I should have black tea and one evening meal on fast days and just get on with it. I'm looking for an easy life, wanting the cake and eating it got me here already! Lol- many thanks-

[carorees]

If you mean a complete fast (apart from water) for 24 hours three times a week, then yes, I think it likely that you would get the health benefits. I know some of the experts that Dr M spoke to think that a 24 hour fast is needed for the cancer prevention and brain benefits. I am inadvertently experimenting with this way of fasting this week (on my first fast day this week, OH cooked a big pot of chilli beans and rice for dinner so it was neither low carb nor probably under 500 cals, so I decided to do 3 days this week and to have a non-calorie counted evening meal on each day). So far, I'm not sure I like it because instead of having a healthy evening meal of lots of veggies, some lean meat/fish and no carbs, I am having more carbs and fewer veggies plus I am feeling hungry on 3 days instead of only two.

Perhaps that is not what you meant by 3 x 24 hr fast days. Are you thinking of having 500 calories during the 24 hours? If you were thinking of having say a normal dinner before 6 pm on Sunday followed by 250 cals for breakfast, 250 cals for lunch and then a normal dinner after 6pm on Monday, it is neither giving your body much of a break from eating nor reducing your overall calorie intake greatly. You would have to keep the dinner to 500 cals to get the same reduction as on the 'vanilla' version of 5:2.

Basically, the benefits of intermittent fasting come from having good long gaps between calorie intakes and from reducing your overall calorie intake by around 20% of your normal daily requirements. Whatever way you achieve these two goals will bring benefits. We don't know whether the 5:2 diet as created by Dr M is the best way of achieving this or not. There are other variants of IF, such as having a daily eating window of 8, 6 or 5 hours (giving a daily 16 hour, 18 hour or 19 hour fast), which you might like to investigate.

Many thanks caroress, I will carry on as I am because I've lost 2.5 lbs this week and the weight off the tummy will bring big benefits also, as I've seen you mention it's the sticking with it is the important part- a lower bmi automatically cuts risks of all sorts. I will play around with the Fasting hours, but it's funny that everyone I speak to is on this diet. Now it really is a phenomenon like Atkins was back in the late 90's ( last time I was slim-lol). Anyway thankyou again for your great advice**