The extra pounds and inches that make a body overweight do not appear overnight. The same can be said of the causes and risk factors for an obese population. Researchers agree that it has taken a lifetime of experiences--perhaps several lifetimes across multiple generations--to build the momentum (and mass) that now dooms millions of Americans to a dismal future of ill health.
In a presentation titled "Obesity and the Life Course" during Cornell's Ecology of Obesity conference held June 6 and 7, 2005, experts viewed obesity from the life course perspective, which, they said, can reveal both early warning signs and opportune moments for constructive intervention.
The life course perspective brings together psychology, sociology, and human development to examine individuals' and groups' periods of stability and periodic changes in beliefs and behaviors over their life spans and over time, according to Elaine Wethington, an associate professor of human development and sociology, and a faculty member of the Bronfenbrenner Life Course Center in the College of Human Ecology. When those beliefs and behaviors involve human health, Wethington adds, the life course perspective helps scientists understand how the environment shapes activity levels, how dietary behaviors change over time, and how people adapt throughout their lifetimes to changing circumstances.
"That's why studies with children are so important. Childhood is when food preferences are formed, and those preferences will have an impact on health and behavior across the life course," Wethington said.
Adherents of the life course perspective think in terms of trajectories, pathways, transitions, and turning points, according to Wethington. They try to learn how culture, external events, and what they call contextual influences affect people's lives, as well as how linked lives--usually within families and workplaces or between partners--have an impact on how people change and adapt.
"Look at how significant others have an impact on health and behavior," Wethington said, "how parents have impact on how their children eat. Or how your work network has an impact on whether you go out to eat and what you eat. Marital partners have an impact on health and weight and how much you eat and when you eat it."
The timing of external events--the announcement of a scientific discovery with health implications, for example, or a major change in healthcare protocols--can be important if that event coincides with a critical period in an individual's life. "You can only adapt in ways that you know at that time, or with the types of strategies that are available to you at your particular age and level of experience," Wethington noted.
She said the concept of trajectories "has the promise of insights into how eating behaviors develop over time and why change can be so difficult. Studies of when trajectories appear to change suggest when it is easier to help someone; that is, when he or she is in a period of transition."
Kirsten Davison, assistant professor of health policy, management, and behavior at the University at Albany's School of Public Health, said she tries to combine knowledge of the "ecology of families" with the life course perspective. To reverse the trend to obesity, Davison said she would provide families "with the skills and support to promote healthy lifestyles among all family members. This is the key place we need to start in the prevention of obesity, and we need to start early. Eating behaviors, physical activity patterns, and TV viewing habits develop early in life, in the context of the family, before children enter school."
Early habits show continuity across time, according to Davison, "and they are more difficult to change as time elapses and habits become ingrained. Parents pass on the genes related to regulation of body weight and they create the environment in which young children live and grow; parents really load the gun and then they pull the trigger. …