Interview conducted by April Cashin-Garbutt, BA Hons (Cantab)
Please could you give a brief overview of your recent research into childhood obesity?
Our research uses mathematical modelling to quantify calorie intake as
children grow at a healthy rate as well as when they develop
obesity.
We showed that the development of childhood obesity required a much
greater increase in calories than previously thought since prior
estimates did not properly account for metabolic changes as children
grow.
How does the new model you have created differentiate between the
healthy weight gain that is normal in childhood, and the excessive
weight gain that results in overweight and obesity?
We started by developing an accurate model of normal
metabolism
and weight gain associated with healthy childhood growth. This involved
understanding the different patterns of body fat changes in boys and
girls as well as their differing rates of growth.
Next, we simulated how increasing the calorie intake above normal leads
to excessive weight gain and obesity. We compared our model predictions
to measurements from real children and found a close agreement thereby
providing us with confidence in our model’s validity.
How does your model differ from existing models?
Our model is the first to accurately simulate both healthy weight gain
during normal growth as well as excessive weight gain during the
development of childhood obesity. Our model is also the first to
simulate the effect of weight loss interventions in obese children.
Is it true that your research indicated that some children may be able to ‘outgrow’ obesity during periods of rapid growth?
Yes, we showed that there may be windows of therapeutic opportunity
when children can outgrow obesity without necessarily losing weight.
By timing a weight management intervention over the course of a growth
spurt, it may be possible to harness the power of growth to
substantially reduce body fat while at the same time increasing muscle
mass.
If the child isn’t too overweight at the start of the intervention, he may be able to outgrow
obesity without even losing weight.
Why do you think fewer girls are able to outgrow obesity during periods of rapid growth?
Because boys typically have a higher growth potential than girls, we
found that timing a weight management intervention to occur during a
growth spurt might be particularly effective in overweight boys.
Nevertheless, overweight girls would also likely benefit from such a
strategy but might have to lose some weight to normalize their body fat.
What impact do you think your research model will have?
We think that our model provides a new tool for researchers,
clinicians, and public health investigators to relate calorie changes to
bodyweight in children. In other words, our model helps explain the
caloric equivalents of weight gain and loss in childhood.
The model can be used at a population level to better understand
childhood obesity prevalence as well as at an individual level to help
clinical management.
How important is the reduction of childhood obesity?
It is imperative to both our nation’s health and the economy that we
reduce childhood obesity. Obese children tend to become obese adults and
the duration of obesity likely has an impact on the risk of
diabetes,
cardiovascular diseases, and possibly some forms of
cancer.
What plans do you have for further research into childhood obesity?
We hope to investigate the use of our model in the weight management of
individual children. We would also like to form partnerships to create a
version of our model that is more useable by clinicians and public
health investigators.
What do you think the future holds with regards to the levels of childhood obesity?
The current levels of childhood obesity are much too high and appear to
be stabilizing at these high levels in certain groups, while continuing
to increase in others.
Where can readers find more information?
Our paper and an accompanying commentary can be found in The Lancet Diabetes &
Endocrinology:
http://www.thelancet.com/journals/landia/article/PIIS2213-8587%2813%2970051-2/abstract
About Dr. Kevin Hall
Dr.
Kevin Hall is a Senior Investigator at the National Institutes of
Health (USA) and his main research interests are macronutrient
metabolism, energy balance, and body weight regulation. His laboratory
performs experiments in humans and rodents and develops mathematical
models and computer simulations to help design, predict, and interpret
the experimental data.
Dr. Hall's mathematical models of human body weight dynamics have been used to quantify the energy imbalance underlying the
obesity epidemic and predict how interventions will impact body weight and composition in individuals as well as entire populations.
Dr. Hall is the recipient of the Lilly Scientific Achievement Award
from The Obesity Society, the Guyton Award for Excellence in Integrative
Physiology from the American Society of Physiology, and his
award-winning Body Weight Simulator (
http://bwsimulator.niddk.nih.gov) has been used by a million people to help predict how
diet and physical activity dynamically interact to affect human body weight
