METABOLISM
What is metabolism/metabolic rate/BMR?
Metabolism is the mechanism by which the food and drink we consume is transformed into a usable form that
enables our bodies to function, and repair and renew its tissues.
Metabolic rate is the rate at which your body burns calories – uses the energy you put in. The younger you are the
higher your metabolic rate, but as we get older it starts to slow down. This explains why some young people seem
able to ‘eat anything and stay slim’ while older people think they ‘only have to look at a cream cake’ to gain weight!
Basal metabolic rate (BMR) is the amount of energy used while at rest.
If you can increase your metabolic rate you can help to speed up your weight loss.
There are 3 main ways that your food uses the calories you consume
1. Basal metabolic rate (BMR)
This is the amount of calories you burn by just being alive – even when you are lying down. BMR accounts for
approximately 60 per cent of calories on average e.g. 1200 calories in someone who consumes 2000.
2. Burning calories by activity
This is the energy used for movement – from blinking to running! This accounts for 30 per cent of calories
burned on average e.g. 600 calories in someone who consumes 2000.
3. Dietary thermogenesis
These are the calories burned in the process of eating, absorbing and digesting food.
Eating
Breakfast really is the most important meal of the day and if you skip it you will impede your weight loss.
Without food your body goes into ‘starvation mode’. This mechanism, which is thought to have evolved as a
defence against starvation, means the body becomes super efficient at making the most of the calories it does
get from food and drink. The main way it does this is to protect its fat stores and instead use lean tissue or muscle
to provide it with some of the calories it needs to keep functioning. This directly leads to a loss of muscle, which in
turn lowers metabolic rate so that the body needs fewer calories to keep ticking over and weight loss slows down.
If someone doesn’t eat breakfast recommend the ‘small changes’ approach – if they don’t eat until 11am each
day, encourage them to start eating for the first time each day at 10.30am for a week or so and then move it to
10am, etc, etc until they are ’ideally’ eating within one hour of waking up.
If someone ‘can’t face food’ that early just reiterate that it only has to be something small to start with – half a
piece of toast, cereal bar, rich tea biscuit, small banana, etc.
• Do not be tempted to cut your calories too far
• Make sure you have sufficient calories to burn fat rather than muscle
• There is even some suggestion that eating spicy foods, especially those containing chilli, can raise your
metabolic rate by up to 50 per cent for up to three hours!
Increase muscle
While aerobic activities such as jogging, swimming, fast walking and aerobic classes help to tone muscle and burn
fat, strength or resistance training, in particular, will increase the amount of muscle you have in your body.
Your metabolic rate which – the rate at which the body burns calories – is partly determined by the amount of
muscle we have. In general, the more muscle we have, the higher our metabolic rate.
This explains why men, who have a higher proportion of muscle, have a faster metabolism than women, and why
a 20-year-old has a higher metabolism than a 70-year-old – again, they have more muscle.
Muscle burns calories 600 per cent more than fat!
1kg muscle burns 120 kcal per day.
1kg of fat burns 20 kcal per day or less.
Having more muscle means that your body is burning those extra calories all the time, even while you are sleeping!
Whereas cardiovascular exercise will burn those calories as a ‘one off’. Therefore, it is important to have a variety
of exercise to assist with your weight loss.
Resistance exercise
Resistance training is another name for exercising muscles using an opposing force e.g. weights or resistance bands.
The beauty of resistance exercise is that it can be done in small spaces i.e.- at home, doesn’t need lots of extra
equipment (your own body weight can be all the resistance you require) and doesn’t need to take up a lot of time.
Does muscle weigh more than fat?
The answer is yes and this may slow down your weight loss initially but this will only be for a short length of time
and ultimately it will help speed up your weight loss. Some weeks you may not notice a weight loss – you may
even see a small gain – but you may also notice the difference in your clothes as you become more toned and lose
inches.
Muscle weighs roughly twice as much as fat...but which would you rather be, toned or fat?!
Eating and exercise
Like driving a car, your body will need to be fuelled to exercise. Aim to eat within two hours before activity (a fruit
portion or half a sandwich) and an hour after the activity. Take care not to add in extra meals and snacks – make
sure they are part of your diet plan.
Stay cool
Did you also know that our bodies burn more calories when we are cool so turn down the central heating! A brisk
walk on a chilly morning could be good for boosting weight loss!