Non-exercise activity thermogenesis (NEAT) is the energy expended engaging in daily activities such as maintenance of posture, fidgeting, and other activities not specifically designated as "exercise." A growing body of evidence indicates that NEAT plays an important role in overall energy balance; for example, differences in NEAT account for the ease with which adults gain or lose weight during over- or under feeding. An intriguing and possibly modifiable component of NEAT is fidgeting-like activity. In lean and overweight adults, modulation of NEAT by augmenting fidgeting can increase short-term energy expenditure. It is unknown whether NEAT can be altered in children, or whether augmenting NEAT in children can change daily energy expenditure or body composition long-term. Children exhibit higher levels of daily activity than adults, suggesting potentially profound differences in energy balance. We propose to study the role of NEAT in children to determine if: a) the fidgeting component of NEAT can be measured accurately and reproducibly in children; b) NEAT can be increased by devices that remind children to engage in fidgeting-like activities; and c) manipulation of fidgeting-NEAT can significantly change energy expenditure and body composition. Thirty lean and thirty overweight children will be enrolled and treated in a pilot feasibility study. By adapting technologies developed to measure activity in adults, children's behavior and thermogenesis will be recorded and analyzed to study question (a). To address study questions (b) and (c), we will ask children to wear a timer that vibrate on a fixed interval schedule and be randomly assigned to two conditions: the intervention or active condition, during which children will be cued by the timer to engage in a fidgeting behavior (rapidly moving their heel up and down), and the control condition, during which children will be asked to perform a less thermogenic activity (noting the cue). Children will then cross over so that each child will complete both conditions. Primary outcome measures for question (a) will be changes in energy expenditure when subjects are asked to fidget in a laboratory environment. The correlation of these energy expenditure measurements with new activity monitoring technologies will also be obtained, so that such equipment can be used for measurements under free-living conditions. For study questions (b) and (c), compliance with prescribed fidgeting regimens in a free living environment and the changes in energy expenditure and body composition will be determined over a 2 week interval. This pilot study will enable the determination of the sample size needed to assess the efficacy of a longer term NEAT intervention in children.
