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Fast800 Misery

60 replies

CareerChange24 · 12/09/2025 18:40

I have been attempting the fast800 since Monday but I can’t get my calories lower than a 1000. I’m 5’3 and clueless how to get it off. How much would I lose on a 1000 in a month? I know people say it’s unhealthy but being 15stone is more unhealthy. Amy ideas for someone who knows how to gain weight. But not lose it.

OP posts:
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therearesigns · 13/12/2025 07:39

The fast800 site has great recipes, meal planning tools and that really helps motivate. 800 is too low for me but you can adapt that to your needs.

Hankunamatata · 14/09/2025 17:39

Fast 800 has a book with meal plans and recipes
There's also a seperate recipe book

I found 2 meals a day were easiest

Orangesandlemons77 · 14/09/2025 17:34

Why don't you try the injections OP probably be easier for you and you could combine it with the fast 800 if you want to

Pessismistic · 14/09/2025 17:15

Hi Op could you mage 500 calories 2 days a week then eat more on the other days. There are apps that will tell you what you need to eat to lose x amout of weight. The first time I tried it I could eat 1200 then 2 days 500 I lost the weight for years then stopped as I was 10/12 I only put on weight when I started hrt now I can’t lose the stomach even if I starve it’s going nowhere fast. Miserable as I have no energy to exercise.

Oldwmn · 14/09/2025 10:39

CareerChange24 · 12/09/2025 18:40

I have been attempting the fast800 since Monday but I can’t get my calories lower than a 1000. I’m 5’3 and clueless how to get it off. How much would I lose on a 1000 in a month? I know people say it’s unhealthy but being 15stone is more unhealthy. Amy ideas for someone who knows how to gain weight. But not lose it.

Reality: weight goes on really easily & then is a bastard to get rid of. Losing weight takes a long time. You need to examine what you're eating & how active you are. You'll be surprised at how often you munch away on 'empty' calories. I used to think I was really active until I got a fitbit & it made me look like I never got out of bed 😀
I can recommend Weightloss Resources. It costs 60 quid every 6 months. It is not a diet plan but a database of food calories + articles about diet plans & exercise. There are community forums on every aspect of weight loss. Get a fitbit (or similar). You won't lose lots of weight fast, you won't lose weight in a smooth arc, there will be days when you say 'bugger it' but you'll get there &, if you've learnt the lessons on the way, you'll stick with it.
I lost 5 stone this way. It took years but it's worth it. I've largely kept it off as well.
Good luck!

vincettenoir · 14/09/2025 07:47

JoBrandsCleaner · 14/09/2025 01:17

I was nearly 15 stone last year. I’ve just been having a protein shake after my swimming in the morning. Then a sandwich normally at dinner time, fruit for snacks then whatever I want for tea and it doesn’t come to more then 1700 calories a day. I’ve lost 2 and a half stone. Just stop stuffing your face with biscuits, cake chocolate and crisps or whatever your problem is.

That’s great. Well done!

JoBrandsCleaner · 14/09/2025 01:17

I was nearly 15 stone last year. I’ve just been having a protein shake after my swimming in the morning. Then a sandwich normally at dinner time, fruit for snacks then whatever I want for tea and it doesn’t come to more then 1700 calories a day. I’ve lost 2 and a half stone. Just stop stuffing your face with biscuits, cake chocolate and crisps or whatever your problem is.

herbetta · 14/09/2025 00:35

Have a look at Ryan Mercer on FB - he shows how much (decent) food you can have for 800 to 1500 calories to give you some ideas.

Crikeyalmighty · 14/09/2025 00:09

I personally am doing ok at 1100 to 1200 5 days a week , around 1600 to 1800 2 days a week (Friday and Saturday) - it’s slow but a downward trend - I refuse to give up my Friday and Saturday night couple of glasses of wine each evening

ErinBell01 · 13/09/2025 23:59

Cut out the cream! I've lost about 20lbs since January by cutting out the crap - chocolate, crisps, popcorn, biscuits and cooking with creme fraiche. If I get the late night munchies I have an oat cake or two. I have fewer carbs and more vegetables; eat on smaller plates; smashed avocado on sourdough (wholemeal if poss) for breakfast, Greek yogurt and berries for dessert.

DarkLion · 13/09/2025 23:52

I’m losing 2-4lb a week on 1780 cals a day on a plan I’m doing. High fibre, high protein and increased steps. I absolutely couldn’t do 800 cals a day and I’d worry about essential muscle loss, nutrient deficiencies and weakness, that can’t be healthy for you either

AnneGel · 13/09/2025 23:46

I did the fast800 and also struggled to get below 1000. However I found the 1000 calorie mark to be the sweet spot where I lost the most. The first week is the hardest.. Join their website and use the chat forums and ask the staff. They are really helpful. They will tell you the 800 calories is more of a rough guide. Concentrate on keeping your net carbs down carbs - fibre. Aim for 25-30g fibre per day. They are clear you should only do it for 12 weeks max and then move to 4:3 and 5:2. I lost 3 stone in 12 weeks.

Break4Love · 13/09/2025 23:42

Op you can put your weight height age and gender into chat gpt and ask it to give the calories you need a day to lose weight. Then every day log your food and exercise in there. It's basically a different way of doing my fitness pal (which I loved and was the only way I've lost weight before). Chatgpt can also just accept photos of packaging of food you're eating rather than you having to type it out. And you can ask it to make suggestions for smart swaps or give you recipes etc. I've found it really useful.

For reference I've been doing that for 3 weeks and have lost 5lbs.

HelenHywater · 13/09/2025 22:35

What do you find difficult about it? Perhaps try to break it down.

I can do the fast 800 if I don't eat my first meal until 1pm and then put as much protein as possible. drink lots of water and keep busy. I would have thought though that at the weight you are, you don't need to go as low as 800 calories.

Dunnowhatimat · 13/09/2025 22:30

I was 100kg at the start of June. Am 89kg now (almost 2 stone down)
I wouldn't be able to sustain 1000 cals for more than a couple of days. I'd be miserable and most definitely binge.
I have about 1500-1700 cals daily. Track it on chatgpt. I exercise in the gym including weights. Increased protein so I hopefully don't lose muscle but only lose fat.
It's very doable at this rate and I do have nice things daily . Please don't do 1000cals. If you're anything like me it'll just make u miserable.

MeridaBrave · 13/09/2025 21:51

No wonder you are miserable. It’s too low. Even 1,000 calories a day is very tough. That’s why people take WLI - as they make eating 1,200 calories a day manageable. Assuming you don’t wa r to do that you need something more manageable and sustainable. Try 1,300 calories a day mostly from veg and lean protein and see how you feel.

pollymere · 13/09/2025 21:41

Often if you consume under 1000 for a short period you won't lose any weight.

Try to have a 500 calorie deficit. You should hopefully be burning over 1500 a day. You should start by losing 2lb a week and then slow to 1-4lb a a month doing this.

Hello12345678910 · 13/09/2025 21:11

I did the fast 800 a few years ago! Certainly was the quickest way ive ever lost weight!
Dont beat yourself up for being at 1000 though, aslong as the food choices are correct ❤️ you've only been doing it a very short time, youll get more in to the swing of it!

ItsOnlyHobnobs · 13/09/2025 21:00

It’s not easy op.

To be fair, if you’re managing to stick to 1,000 that’s not miles off 800.

Where are the additional 200 calories that you just don’t feel you can drop?

for me, I have no off limit with carbs, they cause my blood sugars to spike and rapidly drop, leading to ravenous hunger.

It’s a lot simpler to be ‘in the zone’ if I just don’t contemplate bread, pastry, pasta, rice and potatoes as part of my intake.

InfoSecInTheCity · 13/09/2025 20:58

It’s a hard diet, especially starting on the bigger side, and even more so if you’re starting diet included a lot of carbs. You will feel hungry, as you get more into the habit of following a low carb, high protein and fat diet your body will adjust and you’ll feel fuller but the first 7-10 days are tough to get through.

The good news is that you really really really do not have to eat only 800 calories a day to lose weight. You just need to eat less calories than you use. I’ve made some guesses on age and activity level but at 5ft 3 and 15 stone your TDEE is around 1900, if you eat 500 less than that a day you are on track to lose 1-2 lbs a week, which is 4-8 stone over a year.

BettyBoodle83 · 13/09/2025 20:48

Try intermittent fasting where you have an eating window each day. It’s really easy, no need to count calories, etc. I generally do 19:5 each day with a 36-40 hour extended fast each week.

BIWI · 13/09/2025 20:24

Not meaning to be snippy @CareerChange24 - but I’m wondering exactly why you’re finding it hard. I’d like to help, if I can!

Doyouthinktheyknow · 13/09/2025 20:18

I couldn’t do Fast800, the intake is too low, I would be hungry and irritable and then I’d fail.

I recommend a different kind of intermittent fasting: I do 16:8 or 17:7 and have lost 3 and a half stone slowly but steadily since January this year. I am maintaining now but still intermittent fasting and it still feels achievable. I do exercise as well and focus on a high protein diet to fuel my exercise.

Losing weight is hard and a diet that is too restrictive is doomed to fail for most of us! When I started out I was still eating crisps and other snack foods but I stopped snacking and slowly my diet has changed. I don’t even want crisps anymore!

CareerChange24 · 13/09/2025 20:11

BIWI · 13/09/2025 20:08

Why, then, are you finding it so hard to get your calories down? The recipe books are, IMO, really clear and also mostly very straightforward as well as tasty.

IMO you come across as quite snippy

OP posts:
BIWI · 13/09/2025 20:08

Why, then, are you finding it so hard to get your calories down? The recipe books are, IMO, really clear and also mostly very straightforward as well as tasty.