A guide to Dr Michael Mosley’s Fast 800 Keto diet plan

Michael Mosely headshot

by Claire Tapley |

There can come a time when you feel you need to lose a lot of weight and cutting back on your usual foods just won’t quite do it. This is where the Fast 800 Keto Diet comes in – its premise is to help your body achieve ‘ketosis’.

"Your body is like a hybrid car – it runs on two main energy sources, sugar and fat," explains Dr Michael Mosley. "The Keto diet, and intermittent fasting, encourages your body to flip from one to the other, burning through your fat stores and restoring your body to health."

The key to the Fast 800 Keto Diet is reducing your carbohydrate intake, which helps to suppress hunger, making it easier to stick to a low-calorie diet. In turn, a low-calorie keto diet is an effective way to lose weight. Dr Mosley recommends following the rule of 50:50. "Keep carbohydrates under 50g per day and ensure protein remains above 50g. Try to stick to approximately 800-1000 calories each day."

His meal plans (available at thefast800.com) help you achieve this, and their Mediterranean feel is perfect for summer!

Is it for me?

If you have a lot of weight to lose and are motivated, yes!

Following the plan gives a typical weight loss of around 10kg in 12 weeks, but those with health issues can also benefit. "Research has found the keto diet to be effective for those with Type 2 diabetes to help reduce central obesity, manage their blood sugar levels and potentially reverse the condition," explains Dr Mosley. The plan can prevent the onset of Type 2 diabetes, help to lower blood pressure and improve your sleep. A restrictive diet isn’t for everyone, and isn’t for the long term, but for a quick way to feel healthier, it’s spot on!

Your meal plan

Pick and choose a breakfast, lunch or dinner option from one of these tasty recipes. Follow the plan for 21 days and you could lose up to 14lbs!


Portobello Toast with Spinach & Chickpeas

Serves 1 • 180 calories

2 Portobello mushrooms
1 tbsp olive oil
Sea salt
Black pepper
100g/3 1⁄2 oz raw spinach leaves
1⁄4 tsp ground paprika
30g/1oz tinned chickpeas, drained and rinsed thoroughly
Fresh parsley, chopped

1) Turn the grill to high. Place the mushrooms on
a baking tray, drizzle with oil and season with a pinch of salt and black pepper to taste. Place under the grill for 3 minutes.
2) Place spinach in a pan with a splash of water and cook until wilted. Drain and sprinkle with paprika.
3) Place chickpeas in a bowl and mash with a fork.
4) Divide spinach and chickpeas between mushrooms and garnish with parsley.

Eggs & Broccolini

Serves 1 • 165 calories

2 large free-range eggs
2 tsp white vinegar
1⁄2 bunch Tenderstem broccoli (broccolini), approx 130g/4.5oz
Sea salt
Black pepper

1) Poach the eggs (cook for 3 minutes with the vinegar for a soft yolk or 4 minutes for firm).
2) Before tipping away the hot water, flash boil the broccolini for 1-2 minutes and immediately rinse with cool water to stop the cooking process.
3) Lay the broccolini on your serving dish and top with the poached eggs. Season and enjoy!

Chocolate chia porridge

Serves 1 • 180 calories

25g/1oz rolled oats n 1⁄2 tbsp cacao powder
10g/ 1⁄2 oz chia seeds
100ml/3 1⁄2 fl oz unsweetened almond milk
25g/1oz plain full-fat Greek yoghurt

1) Place the oats, cacao, chia seeds and almond milk in a small pan with 75ml water and slowly bring
to the boil, stirring frequently.
2) Simmer for 3-4 minutes, stirring frequently, until
you have a smooth creamy porridge.
3) Stir in the yoghurt and serve.


Simple Greek Salad

Serves 1 • 267 calories

50g/2oz cherry tomatoes, halved
1⁄2 red pepper, deseeded and chopped
15g/ 1⁄2 oz black pitted olives, halved
1⁄2 head baby cos lettuce, chopped
1⁄2 cucumber, chopped
1⁄4 red onion, sliced
30g/1oz feta cheese
1 tbsp extra-virgin
olive oil
1⁄2 lemon juice
Sea salt
Black pepper

1) Put the tomatoes, pepper, olives, lettuce, cucumber and onion into a bowl. Crumble in the feta and toss everything together.
2) Mix olive oil and lemon juice in a small jar or bowl. Season with salt and pepper.
3) Pour the dressing evenly over the salad ingredients and enjoy.

Salmon sushi

Serves 1 • 381 calories

150g/5oz cauliflower, priced
1⁄2 tbsp tamari
50g/2oz cream cheese, softened
1⁄2 tbsp rice wine vinegar
1-2 sheets Nori paper n 1⁄2 cucumber, sliced lengthways into thin strips
1⁄4 avocado, sliced thinly
40g/1.4oz smoked salmon
1⁄4 lemon juice
Pickled ginger, for serving

1) In a pan over a medium-high heat, fry cauliflower rice with tamari – cook until it dries out (about 5-10 minutes).
2) Allow cauliflower to cool a bit and add to a bowl with cream cheese and rice wine vinegar. Mix together well and place in the fridge until cool.
3) Once the rice mixture is cooled, you can start making your sushi.
4) Place a nori sheet on a board, rough side up. Spread some of the cauliflower rice mixture in a thin layer over the nori sheet, leaving about 2cm/3⁄4in of empty space at the top.
5) Place all of the filling items along the sushi roll – don’t over fill. Roll sushi tightly. Repeat if you have ingredients left over.
6)Cut sushi into 2cm/1⁄2in portions and serve with lemon squeezed over the top and pickled ginger.

Protein-packed salad with egg

Serves 1 • 295 calories

For the dressing:
1⁄2 tsp caper brine
1⁄2 tbsp peanut butter
1 tsp tahini paste
1 tsp tamari
1 tsp apple cider vinegar

For the salad:
1 large free-range egg
60g/20oz canned lentils, drained and rinsed
60g/2oz canned kidney beans, drained and rinsed
15g/1/2oz rocket (arugula) leaves,
1-2 handfuls
1 tbsp capers

1) For the dressing, mix the caper brine, peanut butter, tahini, tamari and apple cider vinegar together in a bowl – add a splash of water if needed to loosen the dressing.
2) For the salad, hard-boil the eggs in a small pan of water for 7-8 minutes then drain and run under cold water to stop cooking. Peel and chop.
3) In a bowl, put the lentils and kidney beans with the rocket (arugula) leaves and capers. Pour the dressing over and enjoy!


Moroccan Meatballs & Zoodles

Serves 2 • 389 calories

300g/10 1⁄2 oz lamb mince
1⁄2 onion, finely diced
Sea salt
Black pepper
2 garlic cloves, minced
1 tbsp olive oil
400g tinned chopped tomatoes
1⁄2 tsp paprika
1⁄2 tsp ground cumin
1⁄2 tsp chilli flakes
1 courgette, spiralised
2 carrots, spiralised
Fresh parsley, chopped

1) In a large bowl, add the lamb, half the onion and garlic. Use your hands to combine. Season with sea salt and pepper and roll the mixture into plump balls, about 4 per serving. Cover and refrigerate to firm up for 10-20 minutes.
2) In a pan, heat the olive oil and fry the meatballs. When they are browned all over, set aside.
3) In the same pan, fry the remaining onion in the meatball juices until it is soft and browned. Add the tomatoes and spices and gently simmer for about 10-15 minutes – add a splash of water if needed. Add the meatballs to the sauce to finish cooking through.
4) Serve your courgette and carrot ‘zoodles’ in a bowl and top with the meatballs and sauce. Garnish with parsley.

Mushroom stroganoff with greens

Serves 2 • 316 calories

1 tbsp extra-virgin olive oil
1 onion, peeled and diced
2 tsp ground paprika
2 garlic cloves, peeled and diced
350g/12oz button mushrooms, sliced n 150ml/5fl oz vegetable stock
3 tsp Worcestershire sauce
150g/5oz broad beans
1⁄4 cauliflower, (approx 200g) cut into florets
1⁄2 head broccoli, (approx. 150g), cut into florets
45g/11⁄2oz plain full-fat Greek yoghurt
50g/2oz alfalfa sprouts

1) Heat the oil in a frying pan and sauté the onion for 3-4 minutes. Stir in the paprika and garlic and cook for a further minute.
2) Add the mushrooms and continue to cook, stirring frequently, for 4-5 minutes.
3) Pour in the stock and Worcestershire sauce, bring to the boil and simmer for 4-5 minutes.
4) Steam the broad beans, cauliflower and broccoli for 5-6 minutes, until tender.
5) Take the mushrooms off the heat and stir in the yoghurt. Season to taste.
6) Serve the stroganoff with the steamed veg and alfalfa sprouts between two.

Fish with carrot and pumpkin puree

Serves 2 • 422 calories

2 carrots, roughly chopped
200g/7oz pumpkin or butternut squash, roughly chopped
1 garlic clove, minced n 20g/1oz butter
1⁄2 lemon, juiced n 300g/101⁄2 oz firm
white fish, two fillets
1 tbsp olive oil
1 tsp dried chilli flake
1 bunch tenderstem
broccoli (broccolini)

1) Boil the carrots and pumpkin together for 10-15 minutes, until soft.
2) Drain the veg and put back in the pot. Mash, or use
a stick blender to puree the veg with garlic, butter and lemon juice. Keep warm.
3) Fry the fish with the olive oil in a pan over medium heat – start skin side down. Sprinkle with chilli flakes and flip after a few minutes – cook until white all the way through and flaking.
4) Steam the broccolini while the fish is cooking.
5) Season everything to taste and serve purée topped with fish and the greens on the side.

Get 25% off the Fast 800

Yours readers can enjoy 25 per cent off Dr Mosley’s The Fast 800 12-week Online Programme at thefast800.com

Disclaimer: This 25% discount applies to new members of The Fast 800 Online Programme. Discount code ‘YOURSDIET’ must be manually entered when prompted at checkout and applies to The Fast 800 Online Programme. The discount is valid until 11:59pm GMT on Monday, July 25, 2022.

Visit thefast800.com to see if The Fast 800 Keto Diet is suitable for you.

Just so you know, whilst we may receive a commission or other compensation from the links on this website, we never allow this to influence product selections - read why you should trust us