The FastDay Forum

If I didn't consume too many calories normally I wouldn't need to diet, so it shouldn't have come as a surprise to me when I wasn't losing much weight on this program the first two weeks. I've been eating too much those 5 days. And because I have an injury and am sedentary right now, as a woman 500 calories is a little high for me on the 2 days.
I started the program from the book--I read it pretty carefully, but okay I skimmed a couple parts. Somehow I missed the whole TDEE part. Is it in the book? I'm not stupid, so it should have been obvious, but I've been a little slow catching on. Thanks to this forum I finally clued in to the TDEE and the idea of 25pct of my TDEE for the fast days and 100-110pct for the other five. And btw, calculate the TDEE based on the weight I want to BE, not the weight I currently am. Okay, sounds like maybe I am a little stupid.
Anyway, heads up to any other newcomers out there, calculate your TDEE and adjust both the fast day calories and your calories the other five. Sure, you can eat anything you want just like you can on Weight Watchers--but it's still calories in, weight on.

[carorees]

You don't need to calculate TDEE for the weight you want to be but for your current weight.

TDEE is not mentioned in the book because, I think, it didn't occur to Michael or Mimi that people would need to get an idea of what eating normally means. I'm pretty sure that neither of them overate really before starting 5:2 so eating normally plus the 2 fast days worked for them. For many others it is reassuring to get an idea about what normal is by calculating TDEE and seeing what that looks like before venturing into not thinking about cals on feed days.

help....i just totalled up yesterday's feast day foods and i ate 3,000 calories! i did not exercise either. my TDEE is 2070 with exercise , my calories totalled 1500 today,plus i exercised. i know we aren't supposed to be worried about calories, but i'm wondering if i should "cut back" my calories tomorrow (Sunday) because of my 3,000 calorie feast day?? My fast days are Monday and Wednesdays. This is the end of my first week.

I think it's important to make the distinction between eating 'whatever' you like on feed days but not eating 'as much as' you like.
I have lost 7 stone by various means and kept it off for over three years but I still have an enormous appetite so can't eat as much as I like!
If it was me I would adjust my calories today if I'd eaten 3000 calories yesterday.

Good point Mari4715! And with Caroline's correction about working off the TDEE of the weight you are now, I agree with everything you say.

Dr M and Mimi's fast diet is successful because it is so simple to describe, in fact it takes about 20 seconds (or less, can someone come up with the fastest description that conveys all you need to know?) Once you start talking about TDEE a whole level of complication arises which would put many people off. So I understand them not mentioning it and I think it was the right decision.

Nevertheless TDEE matters because of the calories in / calories out - we can't get around the basic laws of physics.

I have occasionally felt frustrated here (and maybe let it show sorry ) when people say 'eat more on your feed days to lose more weight', because I think it is exactly what most of us want to hear and shall we say it is 'open to misinterpretation'.

There may be a truth behind it though. I suspect that intermittent fasting (IF) works by allowing your metabolism to run at full pace on normal days and then a slight reduction on fasting days, whereas your body is likely to respond to continuous calorie restriction (CR) by lowering your metabolic rate. So for a given intake of calories over a week IF might well work better than CR for weight loss, because the energy consumption will be higher.

If you are following IF but reduce your eating on normal days below your TDEE this might start to reduce your metabolism and thus your energy burn, and then you have just made it harder for yourself to lose weight. If this is the case, then 'eating more on normal days' might be good advice.

But the big point is that eating on average above your TDEE on normal days will reduce, eliminate or even reverse any weight loss benefits from the fast days. This is not to say you can't go over it on occasion - it's just the average that matters.

Almost everything I have written above I have picked up from this forum BTW - what a great place it is! Any mistakes of course are purely my own...

[Debs]

Further to what Dominic said, this is well illustrated in Brad Pilon's book Eat Fast Eat which shows the fat burning cycle over the 24 hour fast. He explains it quite simply so even I could understand it:)
I think that MM references the book as well. Worth a read.

I am on day 3. I had a fast day on day 1 and followed with 2 normal days. I have lost 3lb already and only have 2st to lose so am happy. On my normal days I am being sensible and sticking to around 2000 cal which is quite a lot when you have been used to dieting on and off for years. I think that i have appreciated my food more on my normal days and am trying to stick to healthier options. I have learnt over the years that there are no quick fixes for dieting but i think I may be able to stick to this one.

[carorees]

Dominic, you are exactly right. Plotting my weight loss against average calories shows that when the average was lower than around 200 cals per day below TDEE went loss stalled, similarly when the average was more than 200 cals over TDEE. Most interesting though is that a few days of being well over TDEE coupled with a similar number below TDEE seems to give the best weight loss. Mixing it up seems to give some kind of advantage.

Thanks for the correction Caroline, and the further comments Dominic. Ironically, this morning was my designated weigh-in day and finally I'm down! Slightly more than 2lbs after two plus weeks. So I'm feeling better about how I'm handling this plan. My husband has met with the same success finally.

I've reflected more on the whole TDEE math thing and realize that to sustain my current weight versus my desired weight there really is only a difference of about 300 calories per day. So it only takes a few bad decisions to pack on the pounds over time. I've also done the math and realized that 2 IF days a week removes on average about 300 calories a day from my weekly total. Thus leading to gradual weight loss over time--as long as I don't overcompensate on my 5 days of "normal" eating. It helps me to understand the science of it.

After years and years of WW (successfully while I stayed on it, but never keeping the weight off) I figured out early on that eating too few calories eventually stalled my effort, and that sometimes a "feast" jump started loss again. So, Caroline I get your point about keeping enough calories coming in. Facing such a big number of pounds to lose, I think I'll try a TDEE of somewhere in between my desired weight and my current weight, though. And if things slow down I'll be the first to say, "okay Caroline tried to tell me".

And I agree! Keeping the premise of the book simple was what drew me in to trying it. I was tired of all the effort of counting points and measuring I had been doing day after day after day, and year after year. I wanted a simpler solution. And I wanted to have days where I wasn't obsessed with navigating restaurant menus, or my social life, or my travel without a food scale, an ingredient list and a points calculator. Although I now plan to use my TDEE as part of my plan too, I hope to do it with a light hand--keeping an eye on portions and excess calories for those five days, but staying relaxed and enjoying life.

Thanks!

ok, i think i get it now. thank you folks for all the input. i really love this forum...to hear what has worked and not worked for others gives me a good gauge of what to do. because i overdid it with my 3,000 calorie feast day, today i will cut back a bit to a bit under my TDEE of 2100 calories (days when i exercise, like today). i like what Carorees said that " a few days of being well over TDEE coupled with similar number below TDEE seems to give the best weight loss. Mixing it up seems to give some kind of advantage". very helpful. thank you again!

Sounds like you have got it well sorted, Mari!

I think Caroline's and your observations about a 'feast' day kick-starting the metabolism are interesting and make sense. I definitely feel the cold in the latter part of a fast day so I am convinced that (in my case anyway) fasting does slows my metabolism.

Maybe the body upregulates metabolic rate upon getting plentiful calorie intake faster than it downregulates when there is nothing coming in. Anyway, not worth trying to micro-manage it I think, I'll just enjoy the fact that it works!

[carorees]

One message worth taking from my observations is that if you have a real feast day eating well over TDEE, there's no need to panic and feel a failure...in fact you can say...great, this will actually help my weight loss efforts, all I need to do is to have a lower calorie day to go with the feast day!

Completely agree - had a blow out last Saturday and Sunday due to family birthday and Mother's Day and really went to town on the chocolate tin, cake and drank far more than normal. Body was telling me to stop eating (I now know the signs due to fasting!) but couldn't stop!!! Then had a FAST day Monday and weighed myself Tuesday and had lost 1lb. Was amazed as was about 3,000 calories OVER in two days! Definitely would suggest if there is no weight loss in a week or two to kick start with a big feast day. Xx

Timely comments from all of you. Just came home from eating too much. Was despairing a bit, but feel more hopeful after reading your entries. "Micromanage" is a good word choice, Dominic. Enough OCD in my life already! Here's to a successful Monday for all.

I still think using the term "feast" day gives the wrong message! Fast and eat normally. We all know why we are in the position of trying to lose weight, over eating. I think that most people by now have some understanding of what a healthy diet is and what foods are calorie loaded and pile on the weight - treat yourself but don't go mad on the normal eating days.
I think that doing exercise on your fast day is also very beneficial. Whether it is that work out at the gym, run along the beach or more walking than normal will only serve to increase your metabolism. A good message that can easily be achieved on 5:2 is - move more, eat less! Good luck everyone fasting today - that includes me!
PS I also love this forum - a great help on fasting days!