With more and more Australians suffering from obesity and excess weight and with most weight-loss methods proving to be incapable of meeting the challenge, more attention is being focused on the “energy gap”, the difference in the intake and the expenditure of energy and the behaviours needed in order to reduce weight and maintain healthy levels both in individuals and the population in general.
Researchers from the University of Colorado in Denver and the Procter & Gamble Company, Mason, Ohio, discussed how the concept of the energy gap could be used as a method for understanding and dealing with obesity. In the November 2009 issue of the Journal of the American Dietetic Association, the investigators detailed the two key factors of the energy gap: preventing excess weight gain and maintaining weight loss.
The researchers estimated that in order to maintain weight loss there needs to be an energy gap of around 100 kcal/day for adults and 100-150 kcal/day for children and adolescents. They estimate that 90% of the population of people could keep the weight they lost off if they could just maintain an energy gap of 100 kcal/day in adults and 100-150 kcal/day for children and adolescents.
In order to achieve weight loss however, the energy gap needs to be much larger, around 200 kcal/day for a 100kg individual in order to lose 10% of their body weight or around 300 kcal/day for a 15% reduction in body weight.
James O. Hill, Ph.D. professor of Paediatrics and Medicine at the University of Colorado states, “This analysis indicates that to create and maintain substantial weight loss (ie, obesity treatment), large behavioural changes are needed. This is in stark contrast to primary obesity prevention in which small behavioural changes can eliminate the small energy imbalance that occurs before the body has gained substantial weight. Because the body has not previously stored this 'new' excess energy, it does not defend against the behavioural strategies as happens when the body loses weight.”
If the energy gap can be properly measured, the concept can serve as a useful tool in creating tailored weight loss and weight maintenance plans. These flexible plans can specify physical exercise programs and diets that have can be adjusted so as to provide greater or lesser physical expenditure depending on the individual’s stamina and a calorie-reduced diet that can also be adjusted depending on the amount of exercise undertaken.
