Fast 800 - what happens after 12 weeks?

[mommybear1]

Hi I'm currently doing the Fast 800 and approaching the 12 week mark. From everything I have read it advises you not to continue with the Fast800 after 12 weeks. Although I've lost well I still have a way to go. I can't find any answers about what to do next ie do I stop the Fast800 at 12 weeks do 5:2 for a week and then restart the fast 800 or do I need to stop the Fast800 for a longer period and then restart? Any answers would be greatly appreciated .

I don't know, mommybear1, so I'm following this thread for an answer. My DH will be in the same position, I think. I think he's going to check with his GP, get bloods done to see how things are, maybe go on 5:2 for a while?

May I ask if you are happy with your progress/ results? Thanks

They recommend the "new" 5:2, so 2 days of 800 calories per week:

thefast800.com/how-to/#the-new-52

Thank you @someonelockthefridgealready it's still not clear how long you have to do the new 5:2 for before switching back. I don't think I will shift my remaining weight on 5:2 happy to do it when I'm closer to target of course but ideally I'd like to stay on 800 to shift the remaining weight but I know it's not recommended. I'm thinking I might go to the 5:2 for 4 weeks and then go back on 800 🤔.

@IsFuzzyBeagMise yes I think that's probably the way to go I'm just fretting over sticking at the same weight or dare I say gaining......

@Lemonades yes I'm very happy it's the first weight management program I've seen such quick results with which has helped to spur me on. I tend to start a diet and give up if the scales don't move as I feel I have put so much effort in for nothing. On this one it's been great to see the scales moving which has motivated me to keep going. I have found TRE brilliant on this. I tend to eat 1-8. Hope that helps?

That's fantastic!! Well done you!!

I’m rapidly approaching week 10 so joining this thread for ideas from those in a similar place. I’ve lost a lot which feels amazing but will still have a fair bit to lose when I finish - I’ll be about a stone from the top of the healthy range. My current plan is to be prepared to lose it more slowly on the 5:2 and to increase my activity which I haven’t done yet during the initial 12 weeks. Or I may do something like 800 calories 3 days a week...?

@LotsOfTrees congratulations on your loss so far! Yes I thought about mixing in the Fast800 I think it will be trial and error. I was already working out on the Fast800 I could look at increasing it but have a toddler DS so it's more finding the extra time for me to do more.

@mommybear The advice on MM website is to move to IF version

"The 800-calorie rapid weight loss phase is safe, for most individuals, up to 12 weeks, as long as you stick to our recommendations, drink plenty of water and take a high-quality multivitamin. We recommend that after 3 months, you move to an intermittent fasting regime and start introducing non-fasting days each week."

From this I'd assume it's for much longer than a week but I guess you could do 4 days at TDEE and 3 days at 800 Cals rather than 5:2.

The site FAQs also say it's not suitable for a heavy exercise regime such as high endurance (eg marathon training etc) so just be aware of your whole lifestyle too.

You could also consider lower than 800 for 2 days eg the original 5:2

I did 5:2 back in 2013 for about 6 months and tried to stick to tdee for 4 or 5 days and under 500 for 2 or 3 days, even managing liquid only a couple of times so under 200.

I was running as well on that and dropped from around 11 stone to 8 stone 7.5 over that time so about 25% of body weight lost.

Now, after several years of allowing a bit of a creep, eating too much junk and lockdown with too much drinking, I'm doing Fast800 but without necessarily strictly counting and allowing some flex for weekends, to get back to a comfortable weight and maintain it - so effectively a reverse 5:2 approach by eating better, cutting alcohol and junk.

Just found something on the old BSD diet forum posted by MM or his team that they don't recommend staying on fast800 everyday after 12 weeks without advice from your GP and also that you should switch to 5:2 version once you get your BMI into the healthy range...

thebloodsugardiet.com/how-long-can-i-stay-on-the-800-cal-plan/

@putthehamsterbackinitscage thank you lots of useful information there. I suspect given that gp appointments are like the holy grail I won't be able to get "sign off" to stay on the 800 although I am still well outside my healthy bmi range. I think as you suggest I'll adapt the 5:2 given my personal time constraints I'm going to be hard pushed to up the exercise.

I must admit I was surprised by the bit about moving to 5:2 when you reach a healthy bmi... I'm just at the top end of that and yet have around 24 lbs to lose to get to target (I'm fairly short with a very small frame - that'll get me to 8.5 stone and typically a 6-8 in Next/M&S vanity sizes.

That's where I was in 2013 after 6 months of previous 5:2 at 500 calories so I know it's achievable, I still look and feel well and strong, so not excessive... 800 cals for 2 days would probably add a year to the time to reach target.

My current plan is reverse 5:2 but not being totally strict about 800 cals... so 5 days Med diet low cal around 800 cals and 2 days more relaxed. Given my bmr is currently 1475 and I have very sedentary job working from home, over the week I'd probably lose around 1lb at that rate so it's not going to be fast in any case.