The word ‘calorie’ has been ingrained in minds over the years.
What’s a calorie, and why are people so worried about it?
The scientific definition: one calorie is equal to the amount of energy needed to heat up a kilogram of water by 1 C, when measured at normal atmospheric pressure and between 14.5 and 15.5 C.
What do calories have to do with any of that?
An easier way to think about it: calories equal energy.
When food is broken down in your digestive system, it releases energy for your body to use. Ten per cent of that energy is used to digest the food itself. Another 20 per cent is for the energy required to do any physical activities. The remaining 70 per cent is spent on your basal metabolic rate: basic life-maintaining functions like breathing and keeping the heart beating.
These three categories together give us the amount of calories someone would need to eat to have enough energy to live. They are affected by age, sex, height, body composition, stage of life, hormones, and how active you are. The average woman needs about 2,000 calories, while the average man typically needs a bit more than that.
In general, women have less lean muscle mass and more fat when compared to men, and fat tissue doesn’t need as much energy to maintain.
However, a pregnant woman needs extra calories during the second and third trimesters because her baby needs calories to grow.
On the other hand, seniors usually needs less because they may not be as physically active.
Food is made up of macronutrients called carbohydrates, protein, and fats, as well as micronutrients, such as vitamins and minerals.
Macronutrients contain calories, but micronutrients do not.
Dietitians generally recommend the following breakdown for your daily caloric intake: 45-65 per cent carbohydrate, 10-35 per cent protein, and 20-35 per cent fat.
These percentages were developed by the Institute of Medicine and are known as acceptable macronutrient distribution ranges.
All three types of macronutrients are useful for your body.
Carbohydrates fuel your brain and provides short term energy stores.
Protein not only maintains muscles and other body tissues, but also plays parts in your immune system and hormones.
Fats are another energy source that also keep most cells in your body intact.
Calories aren’t a bad thing – we need them.
The problem with calories is that what we don’t use is stored away for rainy days in the form of fat tissue.
Although it’s popular to frame carbs or fat as the cause of weight gain, this is a popular misconception.
Excess calories, whether you get them from eating whipped cream or eating quinoa like there’s no tomorrow, can lead to gaining weight.
Have you ever heard of ‘empty calories?’ This phrase refers to food or drink with insignificant amounts of important nutrients despite being full of calories. For example, a bottle of soda or a candy bar may be high in calories because of the sugar or fat content, but low in protein, fibre, and vitamins. So while it is possible to survive off of less healthy foods, your body would be lacking in other key building blocks it needs to keep you in top shape. Something low in calories isn’t necessarily healthy, just as something with more calories isn’t always bad for you.
In the end, it’s all about balance.
While being overly fixated on calories may cause stress and an unhealthy relationship with food, it can be helpful to know what you’re putting into your body if you’d like to make positive changes to your diet.
Joyce Chang is a graduate of the dietetics program at McGill University
(joyce.yile.chang@gmail.com).