Читать книгу The Little Book of Calorie Burning - Литагент HarperCollins USD, Ю. Д. Земенков, Koostaja: Ajakiri New Scientist - Страница 9

There’s a complicated way of working out your calorie needs, and there’s also a simple formula. Let’s start with the more complicated way, by first working out your Resting Metabolic Rate, as follows:

 If you are a woman around 20 years old, multiply your weight in kilograms × 24.2.

 If you are a woman around 30 years old, multiply your weight in kilograms × 24.2 then subtract 2 per cent.

 For each subsequent decade, subtract another 2 per cent. So, a woman of 40 weighing 70 kilos will make the following calculation: 70 × 24.2 = 1,694 1694 – 2% = 1,660.12 1660.12 – 2% = 1,628.92 Her RMR is 1,628.92

 If you are a man around 20 years old, multiply your weight in kilos by 26.4. Then subtract 2 per cent for each subsequent decade.

So, we’ve now established that our 40-year-old woman would burn 1,628.92 kcal a day while doing no exercise at all. But hang on a minute – it does get a little more complicated …

As well as through our RMR, we also burn calories through something called the ‘thermic effect of food’, again – and you’ll like this – requiring no effort at all. This means that when you eat a Danish pastry containing 411 kcal, for example, 10 per cent of these (i.e. 41.1 kcal) are burned in the sheer effort of digestion – leaving only 369.9 kcal to be stored in your hips. Interestingly, some claim that a celery stick uses more calories when being digested than it contains, making it a useful little weight-loss tool (shame it’s so boring to eat).

So, going back to our 40-year-old woman: she would so far have burned 1,628.92 kcal plus another 10 per cent of the total number of calories she eats in the day. But there’s still something else to take into consideration …

The other way in which you burn calories – and the one over which you have most control – is known as the ‘thermic effect of exercise’. This doesn’t just apply to formal exercise sessions, like going to the gym, running in the park or swimming. Every single movement your body makes calls for muscles to contract in some way and that requires energy – although the calories burned while updating your Facebook profile are negligible when compared with those burned running a marathon. In a lazy person the thermic effect of exercise might account for just 10 per cent of the calories burned but in an Olympic athlete, it could be up to 50 per cent.

So the 40-year-old woman we’ve been looking at will burn 1,628.92 kcal plus 10 per cent of her calorie intake, plus all the calories she burns daily through exercise/activity. The resulting figure represents the number of calories she can eat in a day without losing or gaining weight. It’s tricky, isn’t it? There’s a brief summary in the box at the bottom of page 26.

[Your weight in kg × 24.2 – 2% for each decade over 20] – [calories consumed in a day × 10%] – calories burned through activity in a day = no. of kcal you can eat in a day if you want to keep your weight stable

Now let’s look at the simpler formula for calculating the number of calories you can eat in a day without putting on weight:

 If you are female with a lifestyle involving mainly sitting on your butt (you drive everywhere, have a desk job and think exercise is a four-letter word), multiply your weight in kilos by 26.

 If you are the male equivalent of the lazy woman above, multiply your weight in kilos by 31.

 If you are female and tend to be on your feet doing some kind of physical activity (walking, housework, mowing the lawn, etc.) for at least an hour a day and you take proper exercise (running, gym, sport) three times a week, multiply your weight in kilos by 33.

 If you are the male equivalent of the moderately active woman above, multiply your weight by 37.

 If you are a super-fit woman who gets an hour of moderate activity a day and five or six sessions of proper exercise (that makes you out of breath) a week, multiply your weight in kilos by 39.

 If you are the male equivalent of the super-fit woman above, multiply by 44.