18th April, 2012
Most of us are familiar with the term calories, especially if we have ever counted them in a diet! But what are they? Calories are the amount of energy our bodies get out of the food we eat. They measure food energy.
Eating food is like filling your car with petrol. Foods provide the fuel your body needs to run on. Just as about five to ten litres of petrol enable your car to go a certain number of kilometres, food allows your body to move and function. How long it functions depends on the amount of energy (number of calories) you put into your body through the food you eat.
If you don’t fill up the gas tank with fuel, the car can’t start and won’t run. If you don’t feed your body with good food, it can’t function properly and it won’t stay healthy.
Most people associate calories with weight. If a person is overweight, he has to cut calories to lose, or watch his calories in order to maintain his weight. Unfortunately, many people do not understand enough about the caloric value of food to be able to balance their energy input with energy output. Recently, I asked a group of women to name the foods they think are fattening, they immediately reeled out: White bread, butter, White rice, doughnuts, cakes, potato chips, fried plantain, eggs and sweets.
There is no such thing as fattening food in the sense that you will get fat just because you eat any given food. A food can make you fat only if you eat more total calories than you are using up in your daily activities. Any food, even orange juice, carrots, or cabbage, can make you fat if it is consumed when you have already had your daily quota of calories.
We often fool ourselves about the amount of food we are eating. If one-half cup of ice cream has 150 calories, we forget that a full cereal (pap) bowl can have as many as 500-700!
Another easy way to mount up hundreds of calories is to add butter or sugar to our meals. You can add as many as 350 calories to the innocent little 90-100 calorie slice of wheat bread or combining a small bowl of beans with fried plantain. These extras are high in fat, something known to cause hardening of the arteries and heart disease.
I have seen youngsters and adults alike eat a handful of chocolate chip, biscuit, rinsing them down with a large bottle of soft drink. Want to guess how many calories you can consume that way? Don’t be surprised if it is 600-750, or even more!
An average adult man or woman, who is working in a sedentary job can eat only a total of 1,500-1,800 calories per day without gaining weight! Can you understand why it is so easy to gain weight on a typical Nigerian diet? Just 150 unneeded calories a day result in a weight gain of six kilograms in a year.
A fast food meal of fried rice, French fries, or fish sandwich and a soft drink total from 900-1,400 calories. After a lunch like that, there aren’t many calories left for dinner!
With all this talk about burning calories, you wouldn’t think that undereating is a problem, but it is. Low-calorie eating will damage your metabolism. Even 1,200 calories is too low for most people.
We each burn a large number of calories while just resting. Lying still for 24 hours, you burn about 60 to 70 per cent of your total calories. That rate of calorie burn is called your resting metabolic rate, or RMR. It is different for everyone, and it’s determined largely by your age, weight, and lean body mass (or muscle). It can also be influenced by other genetic or hormonal factors. To protect and enhance your metabolism, never eat less than your RMR for a sustained period of time. Otherwise, after several days, your body’s engine will begin to gradually slow down.
Perhaps your relationship with your car will help you better understand how this works. Have you ever waited to fill your tank until after the warning light goes on? I bet you have! In fact, a close friend said she had gone so far as to figure out that she had exactly forty kilometres after her light went on before she actually ran out of fuel. You would think her car would figure this out and start to conserve fuel when she gets that close to the bottom of the tank. No! It just keeps burning petrol at the same number of kilometres per litre.
However, the body is a much smarter machine What happens when you consistently eat less calories than your resting metabolic rate requires is that your body starts to have a conversation with itself that sounds something like this: “Hey, here she/he goes again. She/He is not even going to feed us enough calories for basic survival. Slow the engines….all systems cool down to basic maintenance. We will not starve!”
Yes your body actually slows down the rate at which you burn calories. So, for many dieters, a dangerous cycle begins. And over time, your Toyota jeep has been converted to an incredible economy car – like the original Volkswagen Bug! Now this is great if you’re worried about never having enough food on the table or going into a time of severe famine. But for those of us who enjoy food, it’s best to keep those engines burning high.
A 50-year-old, 5 foot 7 inch, 63 kg female, resting metabolic rate is about 1,400 calories per day. Yet how many of us have been on 800-, 1000-, or 1200-calorie diets? For a clearer idea of your RMR, multiply your current weight times 10 for women and 11 for men. If you are 68 kg, your resting rate is about 1,500 calories.
Does your RMR seem high to you? It may, but don’t fall into old diet habits and eat less than that number. Remember that the only way to burn fat and protect your metabolism is to eat and burn. That means eat your RMR and move, move, move!
Note: If you are more than 30 pe rcent over your recommended weight, it may seem like eating your RMR calories is excessive. In this instance, you may be able to eat slightly lower than your RMR without damaging your metabolism if you are 25 or more kilogrammes overweight.
I encourage you to seek the advice of a registered dietician or licensed professional to determine the right minimum calorie requirement for you. I believe that most obese individuals can safely lose weight eating no more than 2,000 to 2,400 calories per day.
For example if you are a 5 foot 8 inch woman weighing 100kg, your RMR is about 2,200 calories. Nevertheless, it is probably safe for you to eat about 2,000 calories a day which is 200 calories less than your RMR.
You need to also know that while calories are not nutrients, some nutrients do provide calories (energy). Carbohydrates, fat, and protein give your body energy because they contain calories. When you are on a diet, you count calories from foods containing one or more of those nutrients.
While vitamins and minerals do not provide calories, some B vitamins makes it possible for the body to make the best use of the energy that carbohydrates, fat, and protein provide.
Think of it as trying to open a can of liquid condensed milk. You have to use a can opener to open the can to get the milk out. You don’t get milk from the can opener; you get it out of the can. But you need the can opener to get to the milk.
Water and some of the vitamins and minerals are like can openers. They get the energy value out of the carbohydrates, fat, and protein we eat.
New studies have shown that even moderate dieting creates a rebound phenomenon. This means that the body wants to bounce back to it’s old weight. Only slow and steady weight loss that doesn’t “shock” your body will last.