"Nunc cognosco ex parte" now we know partially - this leitmotif of Trent University is equally true for our knowledge of a suspected, growing epidemic of overweight and obesity in Canada, which indicates that some 30 per cent of children and 15 per cent of adults are either overweight or obese or both.

The Statistics Canada Health Report for 2002 is, like the previous 1999 report, based on self-reported heights and weights. Even for nonspecialists, such surveys must be suspicious for several reasons. First, people report their measures in feet, inches and pounds rather than in the more precise metric system.

Secondly, typical home scales weigh only to 130 or 136 kg; thus many very heavy people cannot know their weights anymore, being outside the maximum weighing range.

Thirdly, the reliability of self-reported heights and weights is suspect - a well-known fact. More important, weight is not an assessment of body composition. Under body composition, we understand the various components a body consists of, such as muscle, skeletal, nervous or adipose (fat) tissue. Theoretically, an overweight person could be over-muscular rather than fat, though I agree that this is rare and in reality, overweight is almost always over-fatness. But even normal weights can be over-fat, since weight means little regarding body composition.

However, height, weight and body mass data from 1939 through 1997 clearly points to a substantial increase in the height-weight relationship and proves that in addition to a height increase, well known under the term "secular trend," a real increase in weight has also taken place probably accompanied by an increase in width.

More than 10 years ago the Report of the Task Force on the Treatment of Obesity, stated that national action is urgently needed. Such action could take two directions. One would be an action plan to improve the food intake to energy output balance by stressing better (or less?) nutrition and increased physical activity. Another simultaneous strategy should be a large-scale, Canada wide health and anthropometry survey including many human dimensions, but aimed at the body fat issue. Further on, as in England, the U.S. and Germany, such an all-Canadian anthropometric survey would clarify the problem regarding weight and obesity and simultaneously modernize ergonomic data which are almost nonexistent for Canadians. These data could be taken to modernize school furniture for a young population which is growing in height and weight and suffering on outdated chairs and tables, for updating industrial norms for garments and clothing, transportation and a host of other ergonomic purposes.

Statistics Canada or the federal Health Department would eventually be able to arrive at reliable conclusions regarding changes in body size and shape, in overweight and obesity, which are the result of a modern socioeconomic environment. However, well founded signs for alarm already exist and suspicions regarding an increase in weight and obesity would almost certainly be confirmed. This should be used to activate people and to initiate another, hopefully longer "Participaction" health and fitness program after the first died some years ago.

Little or nothing has since been done to improve the overweight problem in this country though the problem was recognized some ten years before. Each level of administration can and should do something to try and improve the bad situation.

What can Peterborough do? The North End bicycle path from Hunter Street East to the Canal Bridge and then from Otonabee College to Lakefield seems to be very popular for roller skaters, "hikers" and cyclists. To avoid accidents, this path should be marked by a line along its middle and directions should be indicated on each side. Equally useful is the hiking and biking path in Jackson Park. Such paths should become available to more areas in the city, at each side and radiating out into the country. Two paths are not enough for an ever-increasing population.

Sports facilities for basketball, soccer and baseball should be added and more sports should be encouraged for the young and adult populations such as dedicated, organized tours for health similar to the recent "Ride for heart" tour in Toronto, but not only one a year. Rather, the few summer months should be used for some sort of physical activity every month to get families and children out. Two sub-population groups are particularly in need for preventive measures: the poor which have a higher rate of obesity and the Natives in which so-called "maturity-onset" (now starting in children!) diabetes (Type II) is alarmingly on the rise.

Knowing that diabetes type II is now starting in ever younger ages, and that other diseases such as blindness, kidney failure, strokes and heart attacks are associated with it, the health departments on all levels of governments should urgently start attacking these silent killers. Other beneficial effects of physical exerc ise, especially for children and adolescents, are a lessened probability of smoking and drinking, healthier eating habits and improved self-esteem.

I strongly believe that in spite of only partial, insufficient knowledge, the time is ripe for action!

Hermann Helmuth is a professor in the department of anthropology at Trent University. He can be reached by e-mail at hhelmuth@trentu.ca or by phone at 705 748-1011 x 1452.