Healthy lifestyle helps the environment
One reason to maintain a healthy body weight is to prevent diseases. But keeping your weight within normal limits is also good for the environment.
Food production is a major contributor to global warming. A population that maintains a healthy body weight consumes almost 20 per cent less food and produces fewer greenhouse gases than a population in which 40 per cent of people are obese.
According to scientists at the London School of Hygiene and Tropical Medicine, transport-related emissions would be lower because it takes less energy to transport slim people.
They estimate that a population of 1 billion lean people would emit 1 billion tonnes less carbon dioxide equivalents per year than an overweight one.
In nearly every country in the world, the average body mass index (BMI) is rising.
Populations across the world including Hong Kong are getting bigger - 21.6 per cent of the adult population in 2004 were overweight compared with 22.2 per cent in 2008.
'When it comes to food consumption, moving about in a heavy body is like driving around in a gas guzzler,' said doctors Phil Edwards and Ian Roberts.
'The heavier our bodies become, the harder and more unpleasant it is to move about in them and the more dependent we become on our cars.
'Staying slim is good for health and for the environment. We need to be doing a lot more to reverse the global trend towards fatness, and recognise it as a key factor in the battle to reduce emissions and slow climate change.'
A healthy body weight
You can calculate your body weight by using the body mass index (BMI)
BMI = weight (kg) divided by height (m)?
If you are a boy aged 16 and you weigh 60kg and are 1.7 metres tall, then your BMI is: 60/1.7 x 1.7 = 20.76
How to read your BMI: 5 - underweight 5 to 84 - normal weight 85 to 95 - at risk of being overweight 95 - overweight
A BMI of 20.76 falls within the normal weight range. Girls will need to plot their BMI against the chart for girls.
(Source: Centres for Disease Control Growth Chart, US)
Keeping a healthy weight
If you consume more calories than you can use up, those excess calories will be converted into fat and stored in the body.
So maintaining a healthy weight is all about making lifestyle changes that includes eating a balanced diet and incorporating regular exercise. This will help you balance the amount of calories you eat with the number of calories you burn.
Top tips for maintaining the balancing act
Eat regularly and base your meals on starchy carbohydrates, vegetables and fruits.
Eat slowly, your brain needs some time to register the fact that you're feeling full. If you want seconds, wait for 10 minutes before asking for more
Choose fruits as puddings or desserts
Choose grilled or steamed meats and fish rather than deep-fried versions
Eat with your family rather than in front of the TV, you're usually unaware of what you're eating and this encourages you to overeat
Go easy on the amount of fast foods you eat, these are high in fat and calories
Join those extra-curricular sporting activities after school, you'll enjoy them
Walk instead of taking the minibus, bus or MTR for short distances
Use the stairs instead of escalators or lifts
Motivate your family and go for a hike, ride a bike or go skating at the weekends
