My ketogenic diet and intermittent fasting journey

Everything I learned in 3 months of sticking to a keto and fasting regime

16 minute read


In January of 2023 I conducted a 3 month Keto diet as an experiment in health, discipline and routine.

TL;DR: you eat really well, will lose weight, it’s not that difficult, and there are many surprising yet indirect benefits!

It was such an interesting journey that I thought I would collate and share all the information that I wanted to know at the start in one place, so I’ve outlined below the rough journey, steps, learnings, reflections and resources. I’ve written it in note form so it should be easy to scan. Feel free to ask questions!



  • Girlfriend had weight loss goals, was moving in, and we fancied a bit of a reset / challenge
  • A friend had recommended it, was going to start at the same time, and gave us loads of advice
  • It just seemed like good timing


  • Generally eat sensibly, but a lot of bread, pasta, cereal, and treats like chocolate biscuits, pastries, etc
  • Late 40s was beginning to feel bit flabby, and thought it would be interesting to see if I could shift it
  • Had unrealised intentions to get fit, so this seemed like a natural partner to that


  • Aim to lose 10 kg (arbitrary number; no idea what that would look like or if realistic)
  • Aimed for 3 months (long enough to seriously commit but not too long to become a vague goal)
  • Started with Keto then added Intermittent Fasting when we got used to it
  • Did additional exercise to burn the excess calories


  • Will it get boring
  • Will I stick to it
  • What if it doesn’t work

What is it?

Ketogenic (Keto) Diet


  • TL;DR: you replace majority carbs with majority fats (opens new window) (body will burn them) and protein (fills you up)
  • Body switches from burning sugar to ketones; a bit like a Prius running out of petrol (sugar) and switching to battery (fat)
  • After your body produces enough ketones, your body moves into a state called “ketosis”

How to do it

What you can and can’t eat

  • Do eat: meat, fish, eggs, dairy, green veg, nuts, avocado, berries
  • Don’t eat: anything wheat-based (bread, cake, biscuits, cereals), starchy veg or fruit (e.g. root veg, apples, bananas), sugary anything (drinks, sweets, most condiments, processed food, lots of ready-made food, sauces, etc)
  • Yes, it’s limiting, but what you can eat is fantastic
  • Diet Doctor has a great food guide (opens new window)


  • Can lose 1kg per week easily, sometimes .3kg per day

Intermittent Fasting


  • TL;DR: it’s basically “skipping breakfast”

  • You’ll see a lot of ratios; i.e. 5:2, 16:8, etc

    • 5:2 means you fast on the weekdays (5) and eat normally at the weekend (2)
    • 16:8 means you fast for 16 hours and eat for 8 (usually between 12 midday and 8 in the evening)
  • It helps you attain a calorie deficit (you burn more calories (opens new window) than you consume)

    • Recommended calorie intakes are 2500 calories for men and 2000 calories for women
    • We aimed to eat < 1000 calories a day, which is perfectly possible (main meal 600, snacks ~200, drinks ~200)
  • “Fasting” means no food, but you can drink water and unsweetened tea and coffee

Keto + Fasting

Keto and intermittent fasting are incredibly complimentary, and the end result is more than the sum of its parts.

It was actually surprisingly easy and really helped our weight loss. In fact we did it full time for a couple of months and it was no problem, especially since we were already used to not feeling hungry on Keto.

Ironically, skipping breakfast is great because it’s 7 less meals a week to plan, shop and make and find time for!

Our journey


What you need to win

  • Be committed; stick to the programme and see the results!
  • Be organised; shop ahead to make sure you have options
  • Be detail oriented; read and understand the labels

Getting ready

  • Clear out cupboards and fridge of bad foods
  • Organise the fridge so you know what is where
  • Buy and read books for both nutrition and recipe info
  • Created spreadsheets of macros and recipes and meal plans
  • Sign up to Green Chef (opens new window) to do the thinking and shopping for evening meals for us

How we approached it

  • Made list of allowed ingredients + macros (how many carbs, fat, etc)
  • Gathered recipes from internet and books
  • Began counting macros on bought ingredients
  • Changed from cow’s milk to almond milk
  • Green Chef Keto box



  • Keto for 3 months
  • Intermittent fasting from 1 month in
  • Planned and scheduled meals and snacks
  • Willpower (i.e. not eating too much, snacking too much, drinking wine)
  • Regular exercise, even if just a daily walk

Meal planning

  • First month only until we got used to it
  • Planned the week’s snacks and meals then printed it out and put it on the fridge
  • See the spreadsheet in the Resources section at the end; copy and paste from first sheet to Week 1, Week 2, etc

Understanding food labels

  • For carbs (opens new window), look for “Carbohydrates” and “Carbs (of which sugars)”; then take the bigger number
  • For calories (opens new window), look for “kcal” (Kilocalories) rather than kJ (Kilojoules, the metric measurement of calories)
  • Make sure you are clear if the measurement is per 100g, per pack, or per serving (and do the maths!)
  • Other issues:
    • The writing might be really small; use your phone’s camera as a magnifying glass
    • it may be in a different language; use your intuition
    • it may be in a long list of languages; scan through to find yours
    • Kilojoules (kJ) and calories (kcal) may be listed in pairs; the smaller number will be calories


Weekly routine

  • For the first month, plan the week’s meals and snacks on Sunday morning
  • Shop on Sunday afternoon (main meals)
  • Pre-prepare cooked snacks on Sunday evening
  • Shopping trip on Monday mornings (snacks)

Daily routine

  • First thing
    • Wake up any time from 6:30 – 8pm
    • Go to the toilet
    • Weigh yourself
    • Take a shower
    • Drink water, have a tea (after the weigh-in!)
  • Morning
    • Empty the draining rack, dishwasher
    • Coffee and tea in the morning
    • Snack around 10am if not intermittent fasting
  • Day
    • Lunch at 12 or 1
    • Wash up
    • More tea and coffee
    • Snack at 3 or 4
  • Evening
    • Dinner at 6 or 7
    • Wash up
    • Chill or bit of work from 8 – 10:30
    • Bed by 10:30 to 11:30
  • Any time
    • Go for a walk
    • Do some exercise


What we did eat

  • Breakfast - eggs, bacon, sausages, tomato, avocado, protein shake, tea, coffee (only a little milk) unless fasting
  • Lunch - mainly raw food like olives (opens new window), ham, cheese, tomatoes, etc
  • Snacks - nuts, cheese, boiled egg, berries
  • Dinner - Green Chef

Extra tips

  • Breakfast

  • Lunches

  • Main meals

    • Green Chef was an absolute life-saver
      • No need to think, the box arrives on the Sunday then you just cook each night
      • We found 4 meals a week was enough for us; we would probably have one or two nights out in the week and might be more flexible at the weekend, or shop and cook something ourselves
    • We bought an air fryer which was really useful; 15 minutes to cook a batch of chicken or veggies, and really easy to clean (there is a lot of cooking and washing-up on Keto!)
  • Treats

    • Blueberries and raspberries rather than chocolate or sweets
    • Yoghurt, berries, granola, chocolate (>85% cocoa) chips
  • Bought things


  • You can still eat out; substitute chips for salad, leave the stuff you can’t eat (or give it to a hungry friend!)
  • Make sure you always have fresh, raw food at home so you aren’t tempted to binge buy / eat
  • The deli aisle is your friend (cooked meats, cheese, olives, salads, etc)

Making it fun

  • Listen to music or podcasts when you cook so you improve your brain and waistline!
  • Have friends round for Keto dinners
  • Research imaginative recipes


  • It’s great when you hit the next weight category
  • Looking in the mirror and noticing the difference
  • Fasting but still not being hungry until 3pm


  • Cow’s milk has way too many calories, almond is the best, always pick unsweetened
  • Embrace the change (i.e. berries) rather than trying to substitute (i.e. brownies)
  • Keep an eye on calories; don’t overdo it on the snacks, cheese, etc



  • Weigh in each day, first thing in the morning, underwear only (FYI, clothes weigh about 500g)
  • Make sure you pee first (could be a litre of liquid so 1kg weight)
  • Number Two can be another few hundred grams!
  • Don’t panic if your weight goes up and down; it’s completely normal
  • Don’t fixate on weight if it’s making you unhappy; just weight in once a week

How we measured

  • Keto strips at the start, but if you walk the walk, you will be in ketosis
  • Keto blood tests; we bought the machine but it wasn’t really needed
  • Bad breath! On keto it’s absolutely killer in the morning; like fermented dairy and meat 😦

How things changed over time

  • We were very regimented at the start, constantly checking ingredients and their macros
  • We planned every meal for the first month, but worked more on the fly once things became more intuitive


  • Plateauing – about 6 weeks in, we noticed that the weight loss had slowed down, or even stopped. This is when we added Intermittent Fasting; first as an experiment (too busy to eat) then as a strategy (this really works!)
  • Exercise – it really helps to burn more calories than you are taking in
  • Feeling hungry – actually when you’re in keto, you literally don’t feel hungry – it’s very strange!

Making mistakes

  • Going out of ketosis is easy if you’re careless
  • Don’t have a full-milk latte on the way to work!
  • Be careful with sauces, condiments, fizzy drinks, cocktail mixers, etc
  • Getting back into it can take a day or two, but intermittent fasting will get you there quicker


Thoughts on food

How your body reacts

  • You really don’t feel hungry; could go until 3pm without food and not notice
  • Poos are few and far between, it can be as much as 3 or 4 days without going!
  • Your breath smells (opens new window); working from home is a Godsend!

How things changed

  • Became extremely regimented with planning, making and eating meals each day and each week
  • Got very used to cooking and washing up (actually a long-term benefit going forwards)
  • Gained knowledge around calories and macros

Cheating and breaks

  • Going out with friends (you can eat most dishes, ask to substitute chips for salad, or leave some)
  • Try not to make silly mistakes (everything has sugar!) so understand the ingredients, read the label, ask
  • Drinking pure non-sugary spirits such as whisky is fine, but cocktails like Negroni will not
  • Dry red or white wine is also fine, but beers and sweeter drinks like cider is not
  • If you do cheat, internment fasting should get you back in ketosis much quicker
  • If you have to / are forced to take a break, just enjoy it for what it is, and restart when you need to



Real benefits

  • Lost 10kg
    • Down 2 inches on waist – even look good in skinny jeans aged 48!
    • Weight from 89.5kg to 79.5kg or (14st to 12.5st)
    • BMI from 25.3 (overweight) to 22.4 (healthy)
  • I really enjoyed cooking – the time out, recipe box makes it easy
  • Actually, overall Keto was very straightforward and valuable

Hidden benefits

  • Intermittent fasting
    • Cook early, go to bed early, get up early
    • Get a routine, make the most of your time in the evening
    • You really appreciate food when you finally eat!
  • Keto
    • Begin to understand nutrition
    • Understand how dependent you are on carbs
    • Far more considered in shopping choices even after coming off
  • Cooking
    • Get used to cooking, washing up, putting away, keeping the place tidy
    • Get better at shopping, food choices, and making sure you don’t run out
    • Afterwards, appreciate the foods you missed, and understand where you were abusing food

What I loved


  • Life felt very project-oriented for the first month (got easier once we were used to it)
  • Caused tension with me being very focused and girlfriend less detail oriented than I
  • It is more difficult to eat on the fly, especially things like snacks; you notice how almost everything is carb-based (sandwiches, crisps, pies, pasta, etc) but the deli aisle is your friend (cooked meats, cheese, olives, salads, etc)
  • It is more expensive; bread, milk alternative, eggs (shortage in the UK!), olives, etc
  • Lost too much weight on legs, have started exercising again

Other thoughts

  • I think doing it as a couple was easier; there is a lot of cooking and washing upland having someone to share the burden with is really helpful

Thoughts on food

What I missed

  • pastries (only at the start)
  • Chinese food

What I didn’t miss

  • chocolate biscuits
  • bread
  • pasta

What felt overrated when I finally tried it

  • White bread – actually felt blocked and bloated when I did eat it! Now, don’t want to get into the habit again
  • Pizza; no pizza is better than bad pizza, and good pizza is rare to find

What I loved when I finally got to eat it again

  • Ham and cheese sandwich on brown bread
  • A pastry with my morning coffee!
  • Still haven’t eaten lots of food, and it’s been two months since I stopped

What next?


  • Back to sensible eating, but more of a low-carb diet
  • The weight has stayed off since hitting my target two months ago (I’m still 80kg)
  • Won’t just be making pasta every night, actually have stuck to Green Chef keto
  • Staying away from really carby food – I just don’t really like it now, and I understand the costs of eating it
  • I generally eat less now, and am more mindful of what I buy

Going forwards

  • Need to come up with some sensible snacks to eat; have to watch I don’t just eat cheese
  • Trying not to slip into bad habits like biscuits, etc
  • Will use Keto and intermittent fasting as a tool


Here are some of the resources we found and created whilst on the journey:

Planning spreadsheets

Books and websites


Recipe boxes



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