By IANS
New York : If identical twins eat and exercise equally, shouldn’t they then have the same body weight?
Not necessarily, say researchers, who found that identical twins with similar lifestyles can have different body weights and different amounts of body fat.
They relied on a branch of mathematics called “dynamical systems theory” to demonstrate that a class of model equations has an infinite number of body weight solutions, even if the food intake and energy expenditure rates are identical.
Findings of the study have been published in the open-access journal PLoS Computational Biology.
The work also shows, however, that another class of models directly refutes this assumption, predicting that food intake and energy expenditure rates uniquely determine body weight.
Existing data are insufficient to tell which is closer to reality, since both models can make the same predictions for a given alteration of food intake or energy expenditure.
Given the ongoing focus on the prevalence of obesity, researchers Carson Chow and Kevin Hall were interested in the factors that determined human body weight and its stability.
For example, the study considered whether weight lost from a liposuction procedure is permanent.
For the class of equations with an infinite number of body weight solutions, fat removal through liposuction could lead to permanent results. However, opposing models predicted that the body would return to its original weight.
Chow and Hall noted that neither class of models accounts for the many variables affecting how much a person tends to eat, an important factor determining bodyweight.
Nevertheless, for any food intake rate, this latest research suggests that an individual may have an infinite number of possible body weights.