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Fasting / 5:2 diet

Talk about intermittent fasting and 5:2, including what’s worked for others. Mumsnet hasn't checked the qualifications of anyone posting here. You may wish to speak to a medical professional before starting any diet.

5:2 thread 104: Here's to FAST-ening those jeans!!

243 replies

harriethoyle · 10/03/2026 19:38

Welcome to the continuing thread for those following 5:2 or other forms of IF (Intermittent Fasting) such as 4:3, ADF, etc.

Basically it is 2 very low cal days ("fasts") per week - which need not be consecutive - and eat "normally" to maintain on the other 5 days.
For those who have dieted or maybe overeaten for years, eating "normally"
means roughly the number of calories your body needs to maintain - NOT reduce - its weight (see TDEE calculator below).

IMPORTANT
If you have had past diagnosed Eating Disorders or serious MH problems you should NOT do 5:2 or any other kind of fasting.

JARGON alert
16:8 is a different type of fasting, which can be combined with 5:2.
Daily zero-cal fast for 16 hours and eat within an 8 hour window. To lose weight, this needs a weekly calorie deficit as well
b2b (optional) back-to-back / consecutive fast days, each with an increased allowance of 650 calories instead of 500
BMI (Body Mass Index) healthy range is 18.5 - 24.9 for Caucasians. Upper limit may be 22 for some of Asian origin.
FD = single Fast Day: aim for 500 calories (600 for men or 25% TDEE whichever is higher) or 1000 cals for BF
No alcohol or junk on FDs
Even if you exercise strenuously, do NOT increase FD cals to allow for exercise
MFP = My Fitness Pal, a useful App or website to track food & drink calories
miniFD = MiniFD, tel:850-1000 850-1000 calories, no alcohol or junk
NFD = Non-Fast Day, averages around TDEE
NSV / LSV = Non Scale Victory / LifeStyle (change) Victory, e.g. compliment, smaller waist, clothes size
SV = Scale Victory
TDEE = Total Daily Energy Expenditure, the average number of calories you burn in a day, is calculated from your current weight, height, age, activity level.
Aim to average about this for NFDs.
WOE / WOL = Way Of Eating / Way Of Life. We say this instead of "diet", to emphasise that we must make a permanent change in how we eat, to maintain our new healthy weight long term.

Jump in and say hello!!

OP posts:
harriethoyle · 30/03/2026 13:07

well done on a Sunday fast @Buntyforgirls - I think weekend fasters are heroic! I can never manage them...

OP posts:
harriethoyle · 30/03/2026 21:11

Kitchen closing on 622 - back on Wednesday!

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Buntyforgirls · 31/03/2026 07:38

Well done @harriethoyle !
I finished up on 800, so I am pleased with that (am doing the new fast 800- I don't have lots to lose, but gain quickly, and the horrid meno bloat). Exercise included yesterday too.
Slept well, but have woken with a bit of a headache- I need to drink more water.
Have a good day all!

harriethoyle · 01/04/2026 08:54

Good job yesterday @Buntyforgirls - I'm signing in for today's fast. Wrap and a naked burrito with a mound of broccoli for tonight.

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Buntyforgirls · 01/04/2026 09:00

Thank you @harriethoyle , and good luck today.
Rest of week is operation "damage limitation", as lots of events, and then Easter!
Hoping for OMD for today.

mumofbun · 01/04/2026 10:03

I'm fasting today too, first fast on Monday went fairly well. I've just realised my husband has given me two weetabix instead of one for my lunch...he's doing 5:2 as well but turns out he had two weetabix on Monday. Found Monday easier than i expected but feel like today might be harder.

harriethoyle · 01/04/2026 18:35

How did you get on @mumofbun ?

kitchen closing here on 649. MIL tried to feed me a corn on the cob, smothered in butter, god bless her 🤣🤣

definite damage limitation over the long weekend but equally I’m going to enjoy myself without guilt and get straight back on it on Tuesday after a birthday meal for my dsd on Monday. If I resist a biscoff egg or two I’ll be doing well!! They’re deadly…

OP posts:
mumofbun · 02/04/2026 13:31

@harriethoyle 768 apparently...I did eat both Weetabix though. Monday was 689 so I'm quite happy overall.

Do you track calories the other days too? I did find it easier not to snack on Tuesday following the fasting day but weekend might be harder!

harriethoyle · 02/04/2026 13:40

Roughly @mumofbun though at the moment I’m not tracking at the weekends and I know I’m undermining the week’s discipline… DH had surgery a few weeks ago and we’ve been with the in laws but once we’re home in a couple of weeks I’ll resume daily tracking for a while I think.

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mumofbun · 02/04/2026 14:27

@harriethoyle oh no I hope the recovery is going ok! I really struggle to track any calories when out and about so I'm just going to see how I go...

DominoQueen51 · 03/04/2026 07:51

I’m 0.25 up this week, but I did go out and have Nachos and a couple of drinks last night. Tbh I’ve been fighting off a bug all week, haven’t managed my morning exercise the last three days. However, I have been sticking to my fasting window. I’m always a slow loser so don’t really mind and I’m definitely going to be eating some chocolate over the weekend

Buntyforgirls · 03/04/2026 14:41

I managed to lose the 2 pounds I 'found' on hols, now to put them back on again over the weekend!
Happy Easter weekend, everyone, and enjoy the chocolate!

HLBug · 06/04/2026 22:50

Well my great plan of sticking to TDEE as much as possible over the holidays did not succeed…! But I’m back to work tomorrow and will be shifting my mindset back as much as I can. Kids are still off school with DH and I’m WFH for a few days due to office renovations, but I’m going to try and get back to some sense of normality. Not in the right head space to commit to a FD this week, but let’s see how we get on. TDEE is tomorrow’s goal.

Buntyforgirls · 07/04/2026 10:31

Morning! Hope you all had happy Easter weekends!
Good luck today @HLBug .
I am aiming for fast800👍fingers crossed.

Buntyforgirls · 07/04/2026 20:04

Well I did it- just! Hats off to those of you who manage on 500 calories- just wow- does it get easier??
Hope your day went well @HLBug .
I'm off to bed!

harriethoyle · 08/04/2026 18:01

Yes @Buntyforgirls it definitely does - not least because you work out which foods keep you fuller for longer and end up eating them on repeat.

We’re travelling back home from the in laws this weekend. They have been soooo kind but I am longing to be back in my own space with my own control over food, temperature, telly… everything! 🤣🤣 I can already predict a long, long bath in my future.

Back on the fasting wagon from next Monday - will check in nearer the time but I’m likely to do a three FD week to undo the Easter/feeder damage!

OP posts:
Buntyforgirls · 09/04/2026 17:39

👍fast 800 complete, was easier today. Notice on fast days how my portions of veg are so increased.
Still early though, although I don't usually eat after dinner.
Away for the weekend, so here come those pesky pounds again!
Hope all is positive as can be for you all.

Buntyforgirls · 13/04/2026 07:39

Here's to another day- developing a consistent pattern,hopefully.
Enjoy the day all, whether fasting or 'feasting'!

HLBug · 13/04/2026 08:24

Checking in for a MUCH needed return to routine and Monday FD! Schools are back here today and although I haven’t weighed myself I know I’m more bloated and generally feeling rubbish. Nando’s for lunch yesterday definitely did not help Blush

Already planned out my food for the day, and on a cancellation list for a gym class tonight. Even if I dont get a space I’ll get my 10k steps in via the school run.

good luck to anyone else fasting today - we got this.

harriethoyle · 13/04/2026 08:57

I’m with you @HLBug @Buntyforgirls - FD today and possibly a b2b tomorrow or maybe Weds/Thurs b2b. Depends a bit on how work is looking because I like to use my busiest days! Gym already this morning and I’m feeling focused 💪🏻

OP posts:
mumofbun · 13/04/2026 09:14

We still have a week of school holidays here and i'm at work but off later in the week...last week i did two fasting days but one ended up a bit of a bust! Weighed in this morning and seem to have put on what i lost the week before which is a bit disheartening. FD today and i have a class booked for lunchtime so will try and stay strong.

harriethoyle · 13/04/2026 18:20

Kitchen closing here on 630 and back tomorrow for day 2! It’s a busy day but a long one so we’ll see…

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HLBug · 13/04/2026 20:48

Well done @harriethoyle - closing on 712. I was planning for lower but needed a babybel light mid afternoon to keep me sane! Back tomorrow for B2B Day 2.

Buntyforgirls · 13/04/2026 22:35

Awww,,I was doing so well then had a glass of wine- possibly to reward myself for doing so well- terrible self sabotage.
Still on 900, so could be worse- such empty, unnutrious calories though.
Oh well, wont be defeated.
Well done to everyone else!

harriethoyle · 14/04/2026 08:26

That’s vexing @Buntyforgirls - fallen at the last hurdle! Next time keep the wine firmly out of sight or have a gin and slim instead, much lower calories.

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