Calorie counting

The arithmetic of weight control has long been understood: we gain weight when we consume more energy (calories) than we burn off (through living, breathing, moving, etc.). We maintain weight when the input and output are equal. We lose weight when we burn off more than we consume. This is simple enough and in today’s world of smart-phones, smart-devices, smart-people, smart-cars, smart…well, you get the idea…it is a bit “old school” and it is not very fashionable. But it is the cornerstone of weight control because this simple arithmetic cannot be avoided and must be embraced if we are to control our weight. It is also true that many weight loss programmes, products and services prefer to avoid this truth because it is so simple (you cannot sell simple for big profit) and unfashionable (it is not “smart”) and hard (these companies know they have to offer something “easy” if they are going to make a sale) but that is really another whole story…..the point is this: if YOU want to control your weight you’re going to have to understand and accept this reality.

What is a calorie?

A calorie (Cal) is a unit of energy (specifically the ammount of energy required to heat 1000g of water by 1 degree celcius, but that is not important here) used when discussing food. The metric unit is a Kilojoule (kJ) and there are 4.2 KJ in 1 Cal. Calories and kilojoules are describing the same thing.

How many calories do I need to eat to lose weight?

This is the big question. the science is a bit complex here and the answer varies a bit depending on your gender, age, activity level, and some other things. But absolute precision is not really needed here because a practical guideline will work for most of us.

  • The average woman needs to consume 2000 calories (or 8800 kilojoules) to maintain her weight. Eating less will usually result in weight loss. A 10-20% reduction is usually recommended so the average woman, looking to lose weight, should consume around 1700 calories (or 7140 kilojoules).
  • The average man needs to consume 2500 calories (or 10 500 kilojoules) to maintain his weight. Eating less will usually result in weight loss. A 10-20% reduction is usually recommended so the average man, looking to lose weight, should consume around around 2100 calories (or 8820 kilojoules).

Younger and more active people living in cold climates may need to eat more. Older and sedentary people in warm climates may need to eat less. The heavier you are the more you do need to eat to maintain your weight. The lighter you are the less you can afford to eat to maintain weight. But as a rough guide, the above will work. There are many online calorie-calculators where you can plug in your particulars and be shown how many calories you need to eat to maintain, gain, or lose weight. Just google…

How do I do this?

This is the tricky part. all of the above is just basic science and some arithmetic, but using this knowledge is really the hard part.

  1. Set your target. Decide how many calories you want to eat per day.
  2. Read food labels. You need to understand how many calories are in the various foods you eat and that information is all on the label. It may be in calories or in kilojoules but either way it is there.
  3. Track your calorie intake. You can use a simple piece of paper or a sophisticated smart-phone app. It doesn’t matter. You will have to weigh your food or estimate its weight because the food labels will just give you “xxx calories per 100g” so you need to know if your portion is 100g or 300g or whatever, and then do the arithmetic (e.g. 200g of a “60 calories per 100g” food is 60 x 200/100 or 60 x 2 = 120 calories).
  4. Be honest.

Too complicated?

The calorie-counting method described above, and there are many variants on the theme of course, is too complicated and time-consuming for many of us. Mercifully there is another approach…

Understanding that you have been gaining weight and noting that you want to lose weight, what you need to do is eat less than you have been. By less we mean fewer calories. To do this you really just have to be honest about what you have been eating, and then reduce (by about 10-20%). A simple food-diary might help here or you could use a smart-phone app. But even without this, most of us know how to eat “less” don’t we?

Is that all there is to it?

Yes. And no. If you can follow one of the methods described above, honestly and consistently, you will lose weight. You must lose weight really (the basic science is that simple and that true). But of course there are many ways to make it easier and many ways to be healthy while doing so. You should, for example:

  • Only set realistic targets (losing 1/4 to 1/2 kg a week or so).
  • Eat fewer carbohydrates and or choose better (high fibre, low GI) carbs.
  • Eat quality proteins like lean meats, eggs, fish, soy and legumes.
  • Avoid sugar and sugary drinks.
  • Drink 1500-2000ml of water each day, especially before meals.
  • Be active.
  • Avoid crash diets and fad diets. You want gradual sustainable weight loss and a balanced diet.
  • Consider your food-habits and look out for triggers like boredom, stress, television, etc.

We are not going to go into detail on all of this here, but we do recommend you do some homework on each of these points.

Weight control really does come down to some simple but powerful arithmetic and eating fewer calories is really the key to losing weight.

About the Author:

Colin was a medical practitioner (GP) from 1988 to 2000. Since then he has worked in the wellness field, designing, developing and delivering various products and services. Out of clinical practice for many years now he no longer practices medicine formally but retains a keen interest in helping people become more-well versions of themselves. He acts as a wellness coach and not as a medical practitioner today. Colin's approach and philosophy is based on empowerment: the notion that people only need a little help to make choices they usually already want to anyway - it's about respect and support rather than instruction or correction. Colin lives at the Vaal Dam with his wife Cathy. He spends time walking mountains, cycling, motorbike riding, kayaking, sailing and always looking for better & better balance.


  1. Evan Petersen February 6, 2019 at 7:05 pm - Reply

    There is never a better time to eat old school food. back in the days there was not much packaging stuff like today. You never have to count calories if you eat from nature and only singular items etc… Example A cooldrink is not singular as it contain many items, like sugar, water, flavours etc… A health bar contains muesli, sugar, yogurt etc…. You get it 🙂

    An apple is from nature and singular form and from nature and not packaged by Man.

    Sugar is the main killer of diets and Man and best to cut it out completely and get the sweetness from nature. Nature is made to fit the human biology and not man made things.

    basically look at a product and ask yourself who made it or where does it come from? If your answer is nature and nature only then you good to go.


    flavored water is clear to the eye and looks like water, but sugar and flavor was added. Nope the full product is not from nature , but put together by Man.

    muesli and yogurt for breakfast is supposed to be healthy, but the yogurt is filled with lots of sugar and flavors and the muesli is filled either golden syrup (cranola) or fruit pieces that has lots of sugar in the fruit pieces.

    Lets return to mother nature and start appreciating nature for what it is, the heavenly beauty we take for granted.

    • Monique MacDonald February 8, 2019 at 2:25 pm - Reply

      Hi Evan, you make very valid points regarding nature (natural) vs hidden sugar/carbs. Sometimes we are not always aware of the hidden ingredients that could be more harmful than good – it looks healthy – but a closer look – tells you – it is not!!

      You’ve given me quite a bit to think about – I don’t have a weight problem – but I enjoy training and feeling good – sugar makes me tired – but gives energy to some people.


  2. Sammy Rambali February 7, 2019 at 6:40 am - Reply

    I really enjoyed reading your article. It is so informative and tells me exactly how to eat properly. We work in such a pressurized environment on a daily basis and we tend to eat unhealthy everyday at meetings etc. The article really shows us what type of foods to focus on and what is the benefits for our bodies. As we grow older also, our metabolism slows down and this article really helps to put everything into perspective.
    Thank you for sharing such important info which can prolong one’s life by just eating properly.

  3. Mariska Erasmus February 7, 2019 at 6:52 am - Reply

    The first step is to accept that you want to and need to loose weight. Then you need to find a weight loss plan that works for you. And just eating right is not enough. You need to get moving too! And you cannot do it all on your own. It is a proven fact that you need help from someone that can guide you in the right direction. And it cannot be a one day wonder either. It must become a way of life. Change your mindset, change your habits and change your life for the better.

  4. Ntswaki Sedie February 7, 2019 at 7:23 am - Reply

    And it works, my Dr always says it is not the quality but the quantity that matters and yes I agree.

  5. nadia February 7, 2019 at 7:44 am - Reply

    I have always been a avid outdoor adventure type person and get a thrill from hiking, running or anything physical really. As one gets older your metabolism slows down and you somehow reduce the activity due to commitments and free time and still consume the same amount of food and some way somehow can’t seem to lose the weight. I have now started counting calories and try and eat as healthy as possible however along with my physical activity I was able to shed 500 grams a week. So yes I do agree with setting realistic and attainable eating goals along with a basic fitness plan or lifestyle one can keep down the weight.

  6. Vionne Tregurtha February 7, 2019 at 11:11 am - Reply

    Counting calories will help with weight control but for a good quality life and overall health moderate exercise and high quality food is key. This three pronged approach (portion control, exercise and quality food) also help cope with stress.
    There are some great apps which help to count calories – these apps are great to highlight the number of calories we consume.

  7. Noluhando Mvuka February 8, 2019 at 7:42 am - Reply

    I have always thought that eating healthy is expensive and exercising is a waste of time. In last two months I have challenged myself on eating lest amount off food. I can see the results but I know there is still a long way to go, its never too late to be healthy.

  8. Thato February 8, 2019 at 12:31 pm - Reply

    A 2005 study by Szabo and Allwood CW showed that up to 30% of South African women show signs of eating disorders such as Annorexia or Bullimia. This followed the 2002 study by Stein, that indicated an alarming rise in the number of patients suffering from these diseases, and it was suggested that the main causes were increased social media exposure, too rigid food monitoring processes and over-exercising.

    Please bare are in mind that this article can be very hurtful and destructive to some who are working very hard to actually gain weight, in the process of recovering from Anorexia or Bulimia, where controlling food portions, weighing food, reading labels, and measuring your weight continuously are the cornerstones for huge unhappiness and self harm to begin. It is often as important to NOT weigh, measure or count as it may be for others to do so.

    It is a common misconception that eating disorders such as Anorexia and Bulimia only show in people who are underweight. They are as common in those who are overweight. People with Anorexia or Bulimia have the same fears and ails about gaining weight and the same intrinsic desire to loose weight as those that are overweight, but have to fight against those mental ideas daily and do the exact opposite action of trying to maintain or gain weight to be healthy. So reading an article solely focused on weight loss speaks to the illness’s strength on those who suffer with it.

    Perhaps the next article can be on helping individuals gain weight in a world that continuously speaks to loosing it?

    For example, while running at a calorie deficit of 1700 for women (normally 2000, but different for each woman) could help for reducing weight,consuming less than approximately 1500 calories is a known cause of Anorexia.

    It may be more helpful to explain both sides of balance so as not to tip people to the opposite end of the scale unintentionally.

  9. Firoza Dawood February 11, 2019 at 12:51 pm - Reply

    I found that eating in our pause area was adding to inactivity and weight gain. I now manage my time. I take 20 minutes to eat and 15 minutes to walk. I cool down, reply watsapp msgs and return to my desk in 45 minutes. I have also replaced sandwiches at lunch time with salads which I pack with more protein so that it is more satisfying to my hunger. I throw in some chick peas, chicken, boil eggs, sometimes baked beans and I find my salads to be more wholesome. I have a fruit around 3.30 while I work and this keeps my energy levels up. I exercise 3x a week and its working great. Good luck to all my colleagues who want to stay fit. Just do it.

  10. Sharon Vester February 12, 2019 at 5:52 am - Reply

    no one it trained to count calories and our eating habits start as children by our parents – teach parents how to prepare kids meals and it will become a culture – our parents are used to giving us snack like chips and cooldrinks or sweets – they need to teach parents how to prepare meals for the day and that will become a lifestyle for years to come

  11. Mariette February 13, 2019 at 5:13 am - Reply

    Very informative article. Thank you. I have lost 4 kg in 2 weeks from just not eating bread, walking around the block after work and not drinking a glass of wine!

  12. Sarah February 13, 2019 at 9:17 am - Reply

    We need to go back to basics when it comes to what we consume, in this day and age everything is fast, processed and in a box. When we go to the shop we need to steer clear of the quick, boxed and fast food and opt for veggies, fruit and lean meats. It is so much cheaper actually and of course healthier. We need to accept that there is no easy fix. No diet pill, crash diet or shake will make us slim. It boils down to hard work, effort and more a mental and attitude change for sure.
    I keep a food journal and note in short and sweet what I ate for the day. If I have had a bad day I reflect on this and motivate myself to do better the next day. Checking food labels is so important when it comes to weight loss. There are many hidden sugars, preservatives, low quality carbs in foods that claim to be wholesome, healthy and good for you. Education is extremely important when it comes to diet and weight loss. Actually let me not call it diet. It is lifestyle change. A couple of years ago I weighed a whopping 25kgs more than what I do today. I did try all those expensive fads but of course they didn’t work. The day I started to educate myself, make a lifestyle change in what I ate and went back to the basics of not eating those boxed foods and processed take aways my weight dropped, I became healthy and had more energy. With the increased energy levels I started to work out again and today I am now at a healthy weight and nice and fit and this spills down to what I feed my family too. Why would I not want the same for them as I have for me.

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