Office workers whose daily physical exertion amounts to stretching a hand into their bags for another sandwich followed - on a good day - by a few quiet laps around the photocopier would no doubt have been buoyed by recent research comparing their energy output to that of hunter-gatherers. The study showed that members of the Hazda tribe in Tanzania burned no more calories each day than Western office workers, despite walking large distances each day to forage for food.
Asked to explain this seemingly counter-intuitive finding, the team behind the study pointed out the vast majority of energy used by humans is consumed in vital unseen tasks - such as regulating organ functions and keeping our immune systems going. Exercise was "the tip of the iceberg" in energy use. While emphasising that physical activity remains a highly important of component of maintaining good health, the researchers say their study brings into clearer focus the key reason behind the obesity crisis in the Western world.
The bottom line is we are getting fatter because we eat too much - and we eat the wrong foods.
The findings are timely. They dovetail with the release of the Ministry of Health's updated food and nutrition guidelines for children and young people. In response to alarming statistics showing Kiwi kids are ballooning in weight, the ministry has reiterated some guidelines and redrawn others. It will be news to nobody that the guidelines say foods high in fat, salt and sugar should be eaten only occasionally, and children should exercise at least an hour a day.
What is new is a focus on highly caffeinated energy drinks, which are also high in sugar and other additives. In the previous guidelines, issued in 1998, the ministry said occasional consumption of energy drinks was not harmful to health. The new line is the drinks, increasingly being sold in bumper 600ml cans, should be banned for those under the age of 18.
"We're advising young people to avoid them. We think they're harmful to their health," ministry youth health advisor Dr Pat Tuohy said.
Those words should set alarm bells ringing among parents, particularly those with younger children, of whom increasing numbers can be seen consuming drinks which often contain enough sugar and caffeine to set an adult's heart racing. Dr Touhy's message should also send shivers through the ranks of the executives of the companies that make these drinks, fearful they will be deprived of a growing market. But it is probable they will elicit neither reaction.
Indeed, it was possible to detect a weariness in the words of Dr Tuohy, who was almost apologetic about "harping on" with the same messages. What he seemed to be saying was New Zealand has not got to where it sits on the league table of child obesity by heeding the words of experts. Parents ignorant of the long-term health effects of poor nutrition will continue down the same path - and marketing teams will continue to search for new consumers for these products.
A fresh front in the debate opened this week, with health authorities in Auckland pushing for a ban on fast-food advertising. They bemoaned a lack of political will to tackle what they identified as the root of childhood obesity problems, pointing out that the National Government threw out the previous administration's ban on pies in tuck shops.
It is clear the food and beverage landscape has changed markedly in recent years. There are many more options available, of which any number can be classed as being unhealthy. It is worth remembering the choices parents make now will have long-term impacts on their children's lives, and on the wider health system. It can be difficult to control how much exercise a child does, but it is easier to control what goes into their body. Guidelines are a good start - but once again we should point out that, when it comes to ensuring the health of our children and ourselves, the most important controls will forever be parental responsibility and a little self-control.
