Know your daily energy requirement
WHETHER you want to lose weight, maintain your present weight or be able to practice a certain level of physical activity, it is good to know your body’s daily energy requirement.
The amount of food energy you need depends on several factors, one of which is your gender.
”Men’s and women’s energy requirements differ on account of their body composition,” points out dietitian Sara Ramminger.
Men typically have more muscle mass and less body fat than women do.
Since muscle tissue burns more calories than fat tissue does, their energy requirement is higher than women’s.
The body’s organs play a role as well.
”The organs are in fact, responsible for most of the body’s energy turnover,” says German Society for Nutritional Medicine president Dr
Anja Bosy-Westphal.
Although they make up only about 6% of the body’s weight, they account for 70% of the energy the body expends while at rest, she explains.
Energy expenditure drops in old age because you have less muscle mass, more fat and your organs shrink somewhat. Exercise is also a key factor. If you sit at a desk all day, your energy expenditure is low, and your calorie intake should be too.
”If, on the other hand, you help your friends move house, your energy requirement and energy turnover are high, so you can eat more (without gaining weight),” she says.
There are several ways to determine your energy requirement, the experts say.
In competitive sport, for example, energy turnover under physical exertion is sometimes measured.
There are also rules of thumb for calculating your resting energy expenditure, or how much energy you require daily when you’re not physically active.
”The estimation formulas are generally accurate enough for everyday life,” says German Association of Dietitians vice-president Sabine Ohlrich-Hahn.
A rule of thumb for your resting energy requirement (RER) is one calorie per kilogramme of body weight per hour.
So if you weigh 70kg, your daily RER is 1,680 calories.
To roughly calculate their total daily energy requirement, people of normal weight can multiply their body weight by 30, she says.
So, a physically active person weighing 70kg has a total daily energy requirement of 2,100 calories.
For a more precise calculation of your total daily energy requirement, you have to multiply your RER by your physical activity level (PAL) – a figure between 1.2 and 2.0 that represents a realistic estimate of how much exercise you get.
If you have a sedentary lifestyle, your PAL is estimated to be 1.4 to 1.5.
Raise this by 0.3 if you do sweat-inducing exercise four or five times a week.
”A PAL between 1.6 and 1.7 would be desirable from a health standpoint,” Ohlrich-Hahn says. — dpa