How to count calories: a step-by-step plan for beginners

Where to start

You can get started in one evening: find your daily target, then spend a week logging everything you eat without changing a thing. Beginners usually do the opposite, cutting breakfast and dinner on Monday, giving in to a pizza on Friday and deciding that "counting doesn't work". It does, but the first week isn't about losing weight, it's about seeing how you really eat. In 2008 researchers at Kaiser Permanente followed almost 1,700 people on a weight-loss programme for six months, and those who wrote down their food every day lost twice as much as those who wrote down nothing.

Why count at all, and who shouldn't

A calorie is just a unit of energy, like a litre of fuel in a tank, and there's no morality in it. When the body gets more energy than it uses, it stores the rest, and when it gets less, it dips into its reserves, so counting simply tells you which way you're heading.

Almost everyone is sure they know how much they eat. In 1992 Steven Lichtman at Columbia University tested people who "couldn't lose weight" on a strict diet and found they were underreporting their food by almost half. They weren't lying, it's just that snacks, cooking oil and "just a taste" don't stick in memory.

Counting is useful if you want to lose or gain weight and can't work out why it isn't happening, or if you simply want to understand your eating without banning foods. But if you've had an eating disorder or numbers make you anxious and guilty, if you're pregnant or breastfeeding, or if a doctor has prescribed your diet for diabetes, kidney disease or after surgery, counting isn't needed and can even do harm, and these questions are for a specialist.

Step 1: find your daily target

Your target is how many calories your body burns in a day on breathing, heart and brain, movement and digesting food. It's calculated with the equation Mark Mifflin and Sachiko St Jeor published in 1990, from sex, age, height, weight and activity, and the easiest way is our calorie calculator, which shows both a maintenance number and a number for weight loss.

Take a 35-year-old woman who is 165 cm tall, weighs 72 kg, works in an office and goes for a couple of walks a week. She needs about 1,950 kcal a day to maintain her weight and about 1,650 kcal for gentle weight loss. There's no point chasing precision, since any formula is off by around ten percent either way, and after a few weeks of logging your actual weight will show where the truth is.

The most common calculator mistake is activity. If you go to the gym twice a week and sit at a computer the rest of the time, that's closer to "low" than "moderate", and an inflated activity level gives an inflated target, after which it's a mystery why the scale won't move.

Step 2: a week of logging without changing anything

This is the most important and most underrated step. For seven days you eat as usual, no diets and no "starting Monday", but you log absolutely everything. If you start eating less straight away, you'll never find out where the extra calories were coming from, and that is the main thing counting teaches you: for one person it's two syrup lattes a day, for another it's sandwiches in front of the TV at night, for a third it's the oil poured generously into the pan.

When the seventh evening comes, you'll have something most dieters have never seen, a map of how you actually eat. People are often startled by it, since the 1,500 calories a day they would have sworn to tends to come out nearer 2,300 once the lattes, the biscuits at work and the oil in the pan are all written down.

What you must log

Most of the calories that never reach the diary hide in cooking oil: a tablespoon of sunflower oil is 135 kcal, as much as a whole apple and half a banana. Drinks come next, as a 300 ml latte is about 110-150 kcal, a glass of juice 90 and a half-litre bottle of cola 210. A tablespoon of mayonnaise adds about 100 kcal while ketchup adds only 15, a 30 g handful of nuts is about 180, a couple of biscuits with tea 100-150, and tasting while cooking plus finishing the kids' leftovers adds another 100-200 kcal a day. Bread, sugar in your tea and a piece of cheese "with coffee" are food too, and if you ate them, they belong in the diary.

Counting without a scale: palm, spoons and photos

A kitchen scale is the most accurate, but nobody takes one to a café, and that's fine. For everyday counting the measures you always carry with you are enough:

Taking a photo is even easier. A neural network recognises the food in the picture and estimates the grams, and while it does make mistakes, especially with oil and large portions, for counting without a scale it's comparable to eyeballing and takes less effort. How accurate it really is and where it slips is covered in Calories from a photo, and how to take a photo that keeps the error small is in our guide How to take a good photo.

Keep an eye on whether you log raw or cooked weight. Grains and pasta change a lot when cooked, as 100 g of dry buckwheat is about 310 kcal and 100 g of cooked buckwheat about 110, so if you weigh cooked porridge, use the figure for cooked.

Step 3: your first changes

After a week of logging you know your average, and now you can change things, a little at a time, to reach a weight-loss target rather than a starvation diet. Start with the two or three most "expensive" items of your week and drop or swap whatever brings a lot of calories and little pleasure: trading a syrup latte for a plain cappuccino saves 100 kcal with no willpower at all. Add protein to every meal, since it's the most filling nutrient and makes the deficit easier to hold, and how much you need is covered in our article on protein intake. Oil is easier to cut than portions: a non-stick pan and a measuring spoon instead of pouring by eye take off 150-200 kcal a day.

Don't cut more than 15-20% from your target. A deficit of 300-500 kcal a day gives 0.3-0.5 kg of fat a week, which feels slow, but that pace can be kept up for months and a hungry one can't. Why too big a deficit backfires is explained in A calorie deficit without relapses.

How not to quit after a week

People quit counting not because it doesn't work but because it gets tedious. It helps to judge the week rather than the day, since one day 300 kcal over target ruins nothing if the other six are on track. A 10% error won't stop you losing weight, but getting fed up with weighing every cucumber will. Log straight away rather than in the evening, when half the day is already forgotten, because a photo of the plate before eating takes five seconds, and if your breakfast is usually the same, save it once and add it with a tap. Weigh yourself if you like, but don't trust a single morning, as water and salt move the scale by 1-2 kg, and what matters is where the line goes over two or three weeks.

Somewhere around the third month most people can tell the calories in their usual porridge or soup at a glance and only log the new things they try. If the numbers start bringing guilt instead, so that you dread "going over" or skip dinner to keep the total pretty, stop for a while and talk it through with a specialist.

Sources

1. Lichtman SW et al. Discrepancy between self-reported and actual caloric intake and exercise in obese subjects. New England Journal of Medicine, 1992.
2. Mifflin MD et al. A new predictive equation for resting energy expenditure in healthy individuals. American Journal of Clinical Nutrition, 1990.
3. Skurikhin IM, Tutelyan VA. Tables of the chemical composition and caloric value of Russian food products. Moscow: DeLi Print, 2007.
4. Hollis JF et al. Weight loss during the intensive intervention phase of the weight-loss maintenance trial. American Journal of Preventive Medicine, 2008.

MyFoodMate editorial team

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