CICO:  The Calories In / Calories Out Method
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CICO: The Calories In / Calories Out Method

What is CICO?

CICO stands for Calories In, Calories Out and it means that you eat less than you burn.

Whenever you hear that you need to be in a calorie deficit to lose weight, this is CICO.

CICO is a no-frills no BS diet plan. It’s not a quick fix, it’s not sexy, it’s not trendy, it’s just a basic diet plan grounded on the idea that if you eat less food than you need then your body will go looking for additional fuel in your fat stores on your body.

It works slowly, but surely. Be prepared for a long haul. You won’t lose the weight you want to lose in a couple of weeks. You need willpower, you need consistency, you need to be honest with yourself.

To do this properly, you must find your TDEE (total daily energy expenditure) and subtract 500 calories from that and eat that amount. You can do this by counting calories using an app like Lose It! or MyFitnessPal and using a food scale.

What kind of sorcery is this?

It really is simple. Weight loss happens in the kitchen. You EAT calories and then you BURN calories. To lose weight, you need to BURN more than you are EATING. That’s what CICO is. You EAT 1,200 cals a day ad BURN 1,600 cals a day, which would put you in a caloric deficit, which allows you to lose weight.

What about exercise? How much exercise do I need to do?

You don’t even have to exercise as long as you are burning more calories than you are consuming.

It’s pure science and physics. Nothing fancy or fad about it.

Want to hear it again? As long as you consume less calories than your body burns, you should lose weight (assuming there is no medical reason not to), and you do not need to exercise your food calories away.

How do I work out how many calories I need on CICO?

Go to and enter your info, and put your activity as sedentary. If you know your body fat % (even roughly), make sure you put that in, too. This will give you an estimate of how many calories your body burns each day, just existing and going about everyday life with no intentional exertion/exercise. Select the cutting option and it’ll tell you how many calories you should eat to lose a pound or half a kilogram per week (basically it just deducts 500 – this is your “deficit”). Eating 500 calories less a day is 3500 calories less over the week. To lose 1lb / 0.5kg, you need to burn 3500 calories, so by eating this amount less per week you should be losing at least 1lb / 0.5kg a week. If you add some exercise, you will burn some more calories, which will make you lose a bit more.

There’s only one way to screw it up and that’s by not following these simple rules:

  • Track everything that you eat using Lose It! or MyFitnessPal and ensure that your total calories in are less than your TDEE.
  • Don’t count calories burnt by exercising or you might not make much progress – counting calories burnt in exercise is notoriously difficult and none of the fitness trackers out there are accurate for that. They will always overestimate, leaving you with thinking you’ve “earned” a doughnut when you’ve actually only “earned” a banana.

I went for a long run, do I get extra calories?

The amount of calories burned through exercise is difficult to accurately measure. For this reason, most people chose one of two methods.

  1. Ignore calories burned from exercise and stick to a calorie goal that assumes that you don’t work out at all and is the same each day.
  2. Use a set amount of exercise to compute your calorie goal.

What is eating back my calories mean?

Some people will vary their calories in (calories eaten) each day, based on their exercise. This is called ‘eating back.’

Eating back calories means that you have a set amount of calories for the day and if you exercise (eg you might go for a 5km run), you eat back all of the calories that you burned during that exercise.

This can be problematic because exercise calories are inaccurate. They are usually overstated, meaning that your fitness device says that you may have burned 400 calories in a run, however, the real number may be closer to 200. If you were to eat back the full 400 calories, then you will have consumed an additional 200 calories for the day, over and above your calorie allowance.

Some people, choose to eat back half of their calories burned during exercise, especially if you have done very intense, physical exercise like running or cycling.

What do you use to track calories?

I use the free version of Lose It! You can also use MyFitness Pal (MFP).

Because I generally eat the same thing for breakfast and lunch, it’s very easy to fill out. I just copy my meal from the previous day and update the weight of the food (sometimes I might eat 150g of my favourite food, cottage cheese. Other days, it may only be 90g (usually that’s because I’ve run out!).

Do I have to eat ‘diet food’

You can eat whatever you want, as long as it’s within your calorie limit and you stay active.

What’s the difference between CICO and Intermittent Fasting (IF)?

Fasting is about insulin control.

CICO is strictly calorie control.

True fasting is about keeping your insulin quiet as much as possible with short eating windows and water, black coffee or plain tea only during the fasting window. It is not having cream in your coffee or diet soda. It is doing absolutely nothing that might stimulate insulin production therefore keeping your body in fat burning mode for as much time as possible and as often as possible. You will only lose weight with fasting if you keep your manage your CICO. The shortened eating window is usually a good way to manage your calories, assuming that you still keep to your calorie allowance.

CICO isn’t time based, you can eat your 1200-1500 calories slowly throughout the day, or you can combine it with IF and only eat them during a small window of the day.

In theory they both would provide similar weight loss results, but the thing people usually like about IF is how it gives you more freedom to eat more during the hours you can eat, leaving you less hungry and craving more food.

So remember:

Fasting = insulin reduction

CICO = fat burning due to calorie reduction

Isn’t CICO all about restriction?

Absolutely not!

There are two ways to restrict yourself in the CICO method:

  1. You eat less than your calculated daily calorie allowance (usually equal to TDEE – 500 calories, which will result in a 1lb / 0.5kg loss per week). There’s no need to eat less than this amount.
  2. You nutrient-starve yourself during the day (eg maybe you don’t eat anything or you only eat cucumber) so that you can splurge on doesn’t-make-you-feel-good-and-has-low-nutritional-value junk food. It’s called junk food for a reason! Your calorie allowance is your fuel. Feed your body with the fuel that it needs to operate. This doesn’t mean that you can’t splurge. Have that piece of cake if you want it. The only point to remember is that splurging will make your weight loss journey take longer and that’s not necessarily a bad thing.

It’s important to live in a way that you want to eat for the rest of your life. Otherwise, once you’ve lost your weight and your ‘diet’ is over….well that’s when most of us gain it all back (plus some). Because we go back to our old ways. Because we were were on a ‘diet’, we changed (temporarily) how we eat.

I know that for me, I will need to count calories for years, perhaps my whole life. For this year, I’ve set a goal to count my calories for 365 days. Every single day. Even when I have over eaten. It makes me accountable for what I eat and shows me that it’s okay to sometimes have pizza, even when it is outside my calorie limit. It also shows me that losing weight is what they all say, 80% diet and 20% exercise.

So eat a balanced diet. Find the fuel that makes your body hum.

Your body is a furnace

Think of your body as a furnace. If you throw big logs onto a fire, they can burn all night, providing heat and light for hours. Imagine that fire being fuelled by paper and small twigs. It will also burn all night, but it will need constant ‘topping up.’

Protein, complex carbs (like brown rice, sweet potatoes, whole oats) and vegetables are like the big logs on the fire. They provide long lasting energy.

Simple carbs (like white rice and bread) and sugary, junk foods are the paper and small twigs in this analogy. They burn out quickly and need replenishing. Think about eating your daily allowance (say it’s 1600 calories) by eating chocolate and cake. It wouldn’t take much of that type of food to hit 1600 calories, You could practically do it in one sitting. Will that food sustain you (your furnace) for the day? Of course it wouldn’t! Your body will burn that food so quickly and you will be hungry sooner.

Can I lose weight just eating cake and chocolate?

Of course you can! You will lose weight so long as you maintain a calorie deficit (eg, calories in and less than calories burned). A word of warning. This won’t be as pleasing as it sounds. You will not get the volume of food that you need to feel satiated and the simple carbs will digest quickly, making you feel hungry again soon.

Things like cake and doughnuts are calorie dense. Whole foods, like lentils, are nutritionally dense. They will leave you feeling full and take longer for your body to digest so that feeling of fullness lasts longer.

CICO is about taking your existing diet and making it healthier. Eating less rubbish is healthier than eating more rubbish. Of course, eating good food is the healthiest approach, but CICO allows you to do what you can with where you are.

I’d encourage everyone to aim for more balance in the long-term, but I’d also point out you can phase that in. It’s about improving how you eat based on what you used to eat, not comparing yourself to anyone else.

Do I really need a kitchen scale?

Yes, you most definitely do. I have a digital scale that can weight down to a few grams and up to 5kg.

Before I bought the scale I was severely underestimating how much food I was eating. When you weigh almonds or cashews or any nuts for the first time, sit down. It will blow your mind how many calories are in a very small handful of nuts.

For measuring liquids, like oils and milk, I use measuring spoons and cups and enter the millilitres (or liquid ounces) into Lose It!

So liquids you measure in measuring spoons / cups. Everything else you weigh.

Tips for getting started with CICO

  • Get comfortable tracking calories because once you hit goal weight you’ll move into maintenance calories and you’ll have to track in one way or another going forward.
  • If you want to ‘save calories’ for the weekend, you can take your daily calorie allowance and multiply by 7. That gives you your total calorie allowance for the week. Then you can eat less calories during the week to save up calories for the weekend.
  • Weight loss isn’t linear. You will zig zag up and down but look at the overall downward trend.
  • Don’t be afraid of weighing everything (like, absolutely everything) on the kitchen scales!
  • If you feel physically hungry even though you’ve reached your ‘limit’, just eat something! Don’t drive yourself crazy with hunger, just have an extra 100-200 calorie snack if your body is telling you you need it. It’s a marathon, not a sprint 🙂
  • Learn how to read nutritional labels and portions.
  • Overestimate rather than underestimate
  • Enter your food into Lose It! or MyFitnessPal before you eat it. It may change your mind.
  • Some people like to eat the full fat options, and eat less of them. Other people like to switch out high calorie foods for lower calorie alternatives.
  • If you plan on going out to eat with friends or family, see if they have a menu available online ahead of time to check out the calories and decide what you want.
  • If you stay within your daily calorie allowance all week (ie you maintain a deficit) and then decide to have a ‘cheat day’ on the weekend to ‘reward yourself’, you may lose 100% of that deficit and nullify the entire week or weight loss.
  • Water, water, water! Our bodies often confuse signals making you think you’re hungry when you might just be a bit dehydrated.
  • Make small easy changes from refined grains to whole ones, i.e. wholegrain rice, pasta and bread.
  • Try to avoid drinking your calories. Soda / soft drink and sugary tea/coffee should be avoided.

The “am I actually hungry” flowchart


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