Have you ever tried a fast weight loss plan like the Fast 800 diet? Here I have a guest post from fellow blogger Jenny who does this low calorie diet with lots of tips and tricks to help you give it a try!

beef, sweet potato and spring greens on a plate for fast800

Why I chose this plan for weight loss

Like many others, my husband and I watched Michael Moseley’s ‘How to Lose a Stone in 21 Days,’ programme on channel 4. I was inspired to try because the science made sense to me and the food looked good. We were just about to go on holiday, so we decided to do it when we got back.

What is the Fast800 plan?

After watching the programme, I visited the fast800 website and found that there were lots of recipe ideas and information on there. There is a plan you can subscribe to for £99 for 4 months, and that gives you support and meal plans and many more recipes. I didn’t feel like it was necessary, I’m quite disciplined when I put my mind to it. 

The fast 800 diet plan is essentially following 800 calories diet a day for up to 12 weeks and a minimum of 3 weeks. We aimed for 3 weeks and then managed to carry on.

After that, you go onto a maintenance diet plan of 5:2, which is eating normally (with healthy choices) 5 days a week, and then 2 days a week eating 800 calories a day.

The whole diet is based on a Mediterranean style of eating, with a low carb high protein focus. It’s not Atkins or keto, which I was glad about. They do recommend going into ketosis though.

fast800 recipe book on a wooden table with nuts,

How I have followed the plan

As time has gone on, I now eat a low-carb diet and 2 days a week I do an 800-calorie diet. This is easier for me to do on a workday, as there is less temptation and I can take my food with me.

We did buy the fast800 recipe book, which has been really good for us, all the recipes are easy and tasty, they don’t take too long to make and don’t work out as expensive. We spend no more than we usually do on our weekly shop.

I’d really recommend getting the book to start you off. You must be disciplined not to buy any extra snacks or takeaways. We do buy treats for the kids, but fewer than we used to.

When we got back from our holiday, I started meal planning and writing shopping lists for the following week. My husband agreed to do it with me having never dieted himself. He has tried to eat healthily before and to watch what he ate but never tried calorie counting or weighing out portions.

Burrito bowl

How did the first week go?

In the first week, I shed about 5lb! It was great seeing the weight come off. I did get hungry and had cravings, but not too bad. It helps that the food is really tasty.

My husband has lost over a stone in total and his weight loss was faster than mine – men tend to find weight loss easier when compared to women side by side.

I did not lose a stone by three weeks, but I have lost just over a stone so far and I don’t feel like I’m depriving myself which is the main thing. We plan on making this a way of life with the odd treat so that it works for us.

My goal weight is 10 stone, I’m currently 10stone 13lb with a starting weight of 12stone 2lb. The main thing is I have kept it off! I am pre-diabetic too so it’s for health reasons rather than vanity.

Breakfast Bircher
Breakfast Bircher

How I feel

I suffer from fatigue a lot, and I strangely found that I have more energy on this diet and I have greater mental clarity. It’s not a cure-all, of course, I still get days where I need to rest, but I do feel this way of eating is better for me.

My husband suffers from high blood pressure and high cholesterol. Since losing the weight his blood pressure has returned to normal, which he is so encouraged by.

Asian beef salad with nuts, rare beef, cucumber and lettuce perfect on the fast800 plan

What we have found difficult about the plan

The most difficult thing is sticking to the portion sizes! Some meals seem really small whereas others appear bigger. They all add up to similar calories though.

I was excited to try the avocado on sourdough toast, but it was such a small portion it wasn’t worth it. I prefer the pear porridge or breakfast bircher (pictured above) and they fill me up better too.

The other thing is managing cravings for bread and carbs. I thought I’d struggle more not having crisps, but I want bread more. I have a little bit of sourdough bread occasionally with some soup or as a breakfast.

Bread is allowed on the diet, but they advocate sourdough bread and a small amount. My husband struggles late at night because after dinner he then stays up later than I do and gets hungry again.

We’ve caved in and got a takeaway a couple of times, but we got a small kebab and left out the pitta bread. It didn’t make much difference to the scales.

fast800 recipe book on wooden surface with nuts and tomatoes

Tips for succeeding on Fast800 and the 5:2 diet

I would say the number one tip for success is having the support of a partner or close friend. If you’re depriving yourself or eating healthily and your partner is sitting there munching on your favourite high-fat foods, it’s really disheartening. It’s like when you give up smoking, it’s a lot harder if you go it alone.

Next, start as you mean to go on. Get rid of all the snack foods and high carb foods in your house. We have three children and we made them a snack/pudding bag with chocolate bars and any sweets in, and we try to have healthier options like cereal bars and yoghurt for them.

We used to have a ‘treat basket’ but that is now filled with our nuts, seeds, dried fruits etc. for recipes and the odd snack. This was quite honestly a game-changer. We still have crisps in the house, but they are strictly for the children.

Meal planning for Fast800

This is so important. Sit down together at the weekend or whenever is convenient for you and plan for the week ahead, alongside a shopping list. Then you know what you’re having, and it takes the stress away.

It also gives you something to look forward to. We don’t always plan for lunches, but we have ingredients to make salads, we have soups and things like eggs to make omelettes and frittatas.

For breakfast, we either have a shake, eggs, porridge or greek yoghurt and fruit. On the fast800 website they sell shakes, but we just have Tesco own-brand ones that have all you need and are much cheaper.

Strawberry shake with strawberries halved next to the glass and one slotted over the edge of the glass and a red and white striped straw

How to cope when you slip up

Don’t be disheartened if you slip up or the weight loss stalls. If you have a slip-up, even a big one, don’t panic. It doesn’t mean you’ve failed, and you might as well give up. Just start again the next day. We’re all human and have down days.

Don’t beat yourself up, perhaps you really needed it at that time. Re-focus and start again. If your weight loss is stalling over a long period or creeping up, look again at your diet, is there anything you can change up, drink more water, exercise, change the recipes and ingredients.

Asian beef salad
Asian beef salad on Fast800

Our overall thoughts

So, overall, it’s been such a positive change for us. We are still aiming for 800 calories a day for two days a week, but we don’t count up the calories as such, we just use the recipes to help us aim for that.

Some days now we take it as a ‘non-fast’ day but we don’t go mad, we might just have a slightly larger portion and still have healthy fats. Over Christmas, we relaxed a little. Luckily, I only put on 1lb and my husband put on 5lb (I think it was the booze). We are back on it now.

Is Fast800 good for rapid weight loss?

The plan has two stages, the first stage involves rapid weight loss and should be followed for between 2 weeks and 12 weeks only. During this period you should eat 800 calories a day and ensure you include low carbs, high protein (from lean sources) and plenty of vegetables.

The second part of the plan involves intermittent fasting where you stick to the 800 calories just two days a week then eat healthily the rest of the week. This is usually achieved with a low carbohydrate Mediterranean diet. Protein, again, is really important during this phase.

What is the maintenance phase?

When you have achieved your weight loss goal, it is advised to continue with a Mediterranean style of eating with low sugars, limited carbs and if needed one fast day a week where you consume just 800 calories.

Can anyone follow this plan for weight loss?

It is always advisable to speak to your family doctor before starting any diet, especially a diet that involves fasting and rapid weight loss. If you have type 2 diabetes or other health conditions this is extremely important.

Your questions about the plan answered

Is this the same as intermittent fasting or the 5:2 diet?

There are some similarities with both intermittent fasting and the 5:2 diet and the second phase of the Fast800 plan as they use very similar strategies. The first phase of Fast800 however is a more drastic plan for rapid weight loss initially.

Is this a short term or long term diet?

The first part of the plan should be followed for 2 to 12 weeks depending on the amount of weight to be lost, speed of desired weight loss, or if you need to lose weight quickly due to health concerns such as type 2 diabetes.
The second part of the diet can be followed for as long as required however you should always ask your family doctor for advice.

Who devised the Fast800?

The plan was designed by Dr Michael Mosley who has linked his plan with various health benefits. Some are evidenced, others less so.

Is Fast800 like Keto?

The first phase of the plan is very like keto as due to the low-calorie intake your body goes into mild ketosis and burns fats instead of sugars.

Have you been inspired to try? I would love to hear how you get on, let me know in the comments.

If you found this helpful please share!

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  1. Very inspiring, well done on your weight loss, I too suffer from Fatigue, so I will give this combo plan a go 🙂

  2. I’ve always struggled with my weight but since peri menopause struck, it’s been impossible. Thanks for the tips.