Weight Loss Explained
Our body needs energy
Our body needs energy for two reasons: (1) To tick over, and (2) To support
any additional activity.
Tick over
Every second of our life, our body is constantly active. For example,
it takes in and transports oxygen to every cell, muscle, tissue and organ.
It builds, re-builds, maintains, repairs and cleans itself. It counters
infection. It maintains a constant safe temperature and regulates millions
of chemical reactions. So even when we sleep or do nothing, the body is
actively ticking over. About 70 per cent of our energy is used in this
tick over process. For more details, see Metabolism
Additional activity
The moment we get up or start moving around, we need extra energy. The
more active we are and the more exercise we take, the more energy we need.
On average, about 30 per cent of our energy is used up on this additional
activity.
Where do we get energy from?
Our body has two sources of available energy: (a) Energy we take in from
food, and (b) Stored energy.
Source No 1. Energy from food
Our body converts food into energy. This food-energy is measured in calories.
Source No 2. Stored energy
To put it very simply, when we eat more food than we need, the body stores
the excess energy as fat. Women tend to store this fat on their
hips and thighs; men store it around their middle.
THE BASIC LAW OF WEIGHT LOSS
In order to lose weight we must take in fewer calories than
our body needs.
In other words, if you are overweight, it is because your calorie intake
is greater than your energy requirement. Your only remedy? Eat fewer
calories.
Example
If we need 1500 calories a day to tick over and 200 calories for additional
activities, then our total energy requirement is 1700 calories. Therefore,
if we take in 1600 calories from food, our body will take 100 calories
worth of energy from our fat stores, and we will lose weight.
Problem No 1. Our body doesn't like
to lose weight
Our body is not interested in being slim. It is interested only in survival.
So if our food intake is insufficient, it starts to slow down in order
to conserve energy and boost it's chances of survival. This is why weight
loss tends to slow down as we continue to diet.
Solution
Don't just rely on eating less calories. In addition, start exercising.
Why? Because exercise raises your energy requirement. This pressurizes
your body into using up your fat stores thus speeding up weight loss.
Problem No 2. Not all weight lost is
fat
When we first start to lose weight, most of the weight lost is fluid,
not fat. Hence our initial weight loss can be quite rapid. Also, stored
fat requires less energy to maintain than (say) muscle. So as our body
tries to conserve energy, it prefers to retain fat (which costs less energy)
rather than muscle (which costs more). This process is not yet fully understood,
but it's clear that dieting by itself does not guarantee that all weight
lost will be fat.
Solution
The best way to increase your chance of losing fat, is to eat fewer calories
AND take regular exercise. Exercise does not have to be intense or vigorous,
but it must be regular and should amount to at least 20-30 minutes, per
day.
For more details
See Metabolism - Calorie
Guidelines
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