Opinion: Danger zonesPOSTED: 07/27/12 12:42 PM
We always knew that stuffing yourself leads to predictable results. Like, your trousers don’t fit anymore, and worse. Scientists have now divined something we disagree with: eating too much has a larger influence on the increase of obesity among westerners than exercising too little. The number of calories we need is a set human characteristic, the Volkskrant wrote yesterday.
We happily beg to differ: the amount of calories someone needs per day depends on her or his activities. A construction worker burns more calories than a secretary or a politician, to name just a few extremes. A marathon runner burns more calories than a couch potato. And so on.
But the scientist who came up with their newly acquired wisdom studies the Hadza-tribe in Tanzania. They are traditional hunters with a history that goes back thousands and maybe even tens of thousands of years.
In general the western style of living is considered the cause of overweight and obesity. Several factors influence this, like larger portions, higher sugar and fat content, a sedentary existence wherein cars and machines are doing a large part of the work. But about the question whether eating too much and exercising too little is causing overweight, there is no consensus.
The scientists used the Hadza-tribe to examine whether less exercise would have more influence than eating habits. Using the tribe as a role model, the scientists measured the energy consumption of thirty male and female tribe members between the ages of 18 and 75.
When corrected for height, the energy consumption did not differ from that of westerners, while it had been established that the tribe members got much more daily exercise. But at the same time, they are not burning more calories. That is the basis for the conclusion that eating habits are the main cause for the fact that westerners are in general fatter.
Herman Pontzer of the New York-based Hunter College says that this does not mean that exercising is unhealthy.
“People have to exercise sufficiently to remain healthy. But it does not make us thinner; to achieve that we will have to eat less.”
That so? Marathon runners – not the fattest guys on the planet – usually stuff themselves with a carbohydrate diet in the four days before a race. Gaining four to five kilos during those days is not uncommon. But when the runners pass the finish after 42 kilometers and 195 meters, all that extra weight is gone.
Let’s assume that somebody needs 2, 200 calories per day. That is the energy consumption a body needs to stay on a given weight. Everytime this character consumes more than 2, 200 calories per day without chainging habits, weight will increase. Every time (s)he consumes less without chainging habits, weight will decrease.
It is really that simple. So somebody who wants to lose weight in a hurry does not have to go on a starvation exercise. Eating exactly what you always did, combined with a bit of exercise like running or jogging will do the trick.
How much weight someone will lose by exercising depands on several factors, like starting weight, distance and speed. Running 5 miles at a 12-minute pace will burn 472 calories for someone weighing 60 kilos, and 745 calories for someone weighing 93 kilos. At a faster pace, the body will burn more calories. All these figures are easily accessible on the internet.
To lose one kilo of weight, one needs to burn a bit more than 7, 700 calories. Keeping an eye on the balance between intake (food) and output (exercise) will show how much weight is on the way out or – in too many cases, on the way in.
The World Health Organization (WHO) predicts that in three years time, in 2015, one in every ten human beings will be obese (with a body mass index above 30), while 1 in every 4 will be overweight (a body mass index of at least 25). To stay out of these danger zones, we suggest you keep a keen eye on that balance between intake and output.