How many calories do you burn a day?
The average adult burns approximately 2000 calories per day. However a more accurate figure can be calculated by taking into account an individuals age, gender, height, weight and activity levels. Let’s see how these factors determine calorie expenditure.
- Age – generally speaking, the older you are, the fewer calories you burn. This is because as you get older you tend to lose muscle mass, and this slows down your metabolism.
- Gender – on average, men tend to be more muscular than women and so they burn more calories. However this does not mean that a woman cannot burn more calories than a man of the same size.
- Body size – as weight & height increases, so does metabolism. Body fat composition also plays a part; muscle has a higher metabolic activity than fat so the more lean muscle you have, the more calories you burn.
- Activity levels – as a person becomes more active, their calorie expenditure increases. Exercise intensity and duration both play a part in determining how many calories you burn.
Your body makes use of calories for ventilation, temperature regulation, digestion and blood circulation. Your BMR, or basal metabolic rate, gives you an indication of the number of calories you would use if you were to do nothing but rest for 24 hours.
BMR measurements are taken in a dark room, after you have slept for 8 hours and fasted for 12 hours. Your RMR or resting metabolic rate also provides an indication of the number of calories that you burn whilst at rest, but is measured under less strict conditions than BMR.
There have been a number of algorithms that have been formulated to provide an estimation of BMR and RMR. A relatively new algorithm which is considered to be one of the most accurate is the Mifflin-St.Jeor equation. Its formula is as follows:
Women: 10 x weight (kg) + 6.25 x height (cm) – 5 x age (years) – 161
Men: 10 x weight (kg) + 6.25 x height (cm) – 5 x age (years) + 5
These equations will provide you with an estimate of the number of calories you burn whilst at rest. You then need to multiply this number by an activity factor, to determine your actual calorie expenditure:
- sedentary lifestyle (little to no exercise): x 1.2
- slightly active (exercise 1 – 3 days a week): x 1.375
- moderately active (exercise 3 – 5 days a week): x 1.550
- very active (exercise 6 – 7 days a week): x 1.725
- extremely active (exercise more than once a day): x 1.9
We have created the easy to use calculator below to help you estimate your daily calorie expenditure. The “Maintain weight” number is what you should keep a note of.
This calculator will never show a number below 1000 calories per day. Please speak to a qualified health professional before attempting to eat less than that.
For example, a 25 year old lady who weighs 135 pounds, is 5 feet & 8 inches tall and exercises 4 times a week, will on average burn approximately 2200 calories per day.
The number of calories that you burn on one day can vary greatly from another (being largely dependent on how active you are on a given day), however the calculator above will provide an average daily estimate.
How many calories should you burn a day?
The number of calories that you should aim to burn depends on your overall goals and is based on two very important factors: diet and exercise.
Weight management comes down to a simple equation: calories in – calories out. If this number is positive, you will end up gaining weight over time. The opposite is also true; a negative number will lead to weight loss.
If you want to lose weight, you should aim to consume fewer calories than your body uses up. This can be achieved by eating foods that are low in calories but which are also satiating at the same time.
Foods differ in the number of calories that they provide. For example, 100 g of peanuts (which contain a lot of fat) will provide you with 567 calories. On the other hand, 100 g of cauliflower (which is mainly made up of water), will provide you with only 25 calories!
This doesn’t mean that a person who wants to lose weight should completely avoid nuts and other fat rich foods. They can still be enjoyed, but should be eaten in moderation. A large part of your diet should consist of vegetables, fruits, grains, lean protein and plenty of water (which has 0 calories!).
Consuming fewer calories than you require is known as a calorie deficit and will force your body to use its fat stores as a source of energy. An easy way to keep track of your calorie intake is to use an app such as myfitnesspal. The app is available for both iOS & Android devices and allows you to monitor your calorie intake on a daily basis.
It is recommended that you shouldn’t consume fewer than 1000 – 1200 calories a day without supervision from a medical professional.
If you want to lose weight, you should also aim to exercise at least 3 – 4 times a week; regularly engaging in physical activity keeps your metabolism running well and burns more calories.
High intensity interval training (also known as HIIT) is a well known way to boost your metabolism via exercise. Weight training is also important as it builds muscle, which in turn boosts metabolism.
To gain weight, you need to consume more calories than your body requires. However this doesn’t mean that you should eat calorie rich junk foods, whilst not exercising at all. Doing so will indeed lead to weight gain, but most of the weight will be in the form of fat. A muscular individual can have the same body mass as an overweight individual, however they will look radically different in the mirror.
You should eat foods that are both nutrient and calorie dense. Luckily there are lots of these types of foods available, including nuts, seeds, grains (such as oats & quinoa), beans, fish and avocados. It is important to include foods that are rich in high quality protein, carbohydrates & fat.
Weight training is crucial when you want to gain weight. This is because you want to build muscle and not just store fat. Regular weight training will force your body to use the extra calories that you are consuming (particularly from protein) to build muscle, rather than only storing them as fat. Granted, some of the excess calories may be converted to fat but not nearly as many as if you didn’t exercise at all.
If you aren’t able to gain weight, chances are that you aren’t eating enough food and simply need to increase your caloric intake. A lot of people who are trying to gain weight tend to overestimate the amount of food (and calories) that they consume, and need to eat more. You should not stop exercising (unless you have an injury or illness) in an attempt to burn fewer calories, as this can have negative consequences of its own in the long run.
Boosting your metabolism and calorie expenditure
There are a number of ways that you can boost your metabolism:
Make sure you are eating enough – when people are trying to lose weight, they sometimes reduce their caloric intake dramatically. This can be counter productive because it puts your body in starvation mode and forces your metabolism to plummet. Doing so also breaks down muscle tissue as a source of energy. So whilst it is true that you need to remain in a caloric deficit to lose weight, make sure you aren’t starving yourself.
Drink coffee – studies have shown that caffeine consumption can increase metabolic rate slightly. Caffeine also boosts exercise performance. So drinking one or two cups of coffee per day may help boost your metabolism. Green tea is a great alternative.
Eat enough protein – studies have shown that a high protein intake can boost metabolism. High protein diets have been shown to increase the number of calories burned per day by about 100; this is particularly effective when you are in a caloric surplus. There are plenty of protein rich foods available, including eggs, beans, fish, unprocessed meat and certain vegetables.
Drink lots of cold water – H20 is the healthiest beverage on the planet, yet most people don’t get enough of it. This study had particularly impressive results; it showed that drinking 500 ml of water increased metabolic rate by 30%!
Get enough sleep – researchers have noticed links between sleep and metabolism, so it is important to ensure that you are getting enough high quality sleep, on a daily basis. Everyone is different, but the general recommended amount is 7.5 – 9 hours per day.
High intensity interval training – this type of training involves doing short bursts of intense activity, followed by longer periods of the same activity at a more relaxed pace. For example you could sprint as fast as possible for 20 seconds and then jog at a comfortable pace for a minute; repeat this cycle for 15 minutes. HIIT has been shown to boost metabolism for up to 24 hours.