The energy equation

When it comes to weight, we all know the maths: do more, eat less and lose weight; do less, eat more and gain weight. But is it really as simple as that? Sports therapist, Katie Hiscock talks figures...


What's in a calorie?

A kcal is a unit of energy contained in food and drink. UK guidelines currently advise an average of 2,000 calories per day for women, 2,500 calories for men and 1,800 for children aged 5 to 10. These guidelines help steer us in the right direction but they are approximate figures. If you're keen to find out a more accurate figure you need to work out your Total Daily Energy Expenditure - there are numerous tools available to help you calculate this online.

Generally speaking, how many calories your body really uses each day depends on a number of key factors:

  • Your age, height and sex
  • Your basal metabolic rate (BMR) - the number of calories you'd burn even if you stayed in bed all day
  • The amount of lean muscle mass you hold - lean muscle burns calories faster, even at rest
  • The activities you do - a minute of running is rarely the same as a minute of cycling (see the list below to see calorie expenditure by sport)
  • How much you push yourself in the activities you do - the more you sweat and struggle to catch a breath, the more calories you'll be burning

In reality, a body builder or well-trained athlete may need three times as many calories as the 'average' person a day just to maintain their weight, that can be up to 6,000 kcal for some athletes!

Move more - eat more

Running on bridge

Because exercise builds muscle and muscle is the body's most efficient calorie burner, keeping active can be a more efficient way to watch your weight than shunning scones and dodging doughnuts. And upping your activity level doesn't necessarily mean entering next year's marathon either. Walking the dog for 10 minutes longer each day or hoovering the stairs that bit more rigorously all counts. Here's what that slice of cake equates to in activity terms...

  • Aerobics for an hour: 533 calories
  • Rowing for an hour: 438 calories
  • Running for 30 mins at 7.5 minute miles: 420 calories
  • Running for 30 mins at 12 minute miles: 303 calories
  • Skiing for an hour: 314 calories
  • Swimming for an hour: 423 calories
  • Slow walking for an hour: 204 calories
  • Leisurely cycling for an hour (10mph): 292 calories

(Estimated calorie expenditure based on a person with a weight of 72kgs)

How to have your cake and eat it...

You don't need to forgo your favourites completely when counting calories. Instead pick the healthier option when it comes to meal choices and cooking ingredients and save the treats for a special occasion. One gram of fat contains nine calories, while both protein and carbohydrate contain just four calories per gram, therefore if you replace high saturated fat foods with those rich in protein and carbs you can still tuck into a hearty meal without feeling guilty.

Here are some low calorie recipe ideas to get you started


Katie Hiscock is a fitness writer with diplomas in personal training and sports massage therapy. With an interest in sports nutrition, antenatal exercise and injury prevention, she works as a therapist for Brighton & Hove Albion

All health content on is provided for general information only, and should not be treated as a substitute for the medical advice of your own doctor or any other health care professional. If you have any concerns about your general health, you should contact your local health care provider. See our website terms and conditions for more information.

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