NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Determinants Affecting Physical Activity Levels In Animal ModelsWeight control is dependent on energy balance. Reduced energy expenditure (EE) associated with decreased physical activity is suggested to be a major underlying cause in the increasing prevalence of weight gain and obesity. Therefore, a better understanding of the biological determinants involved in the regulation of physical activity is essential. To facilitate interpretation in humans, it is helpful to consider the evidence from animal studies. This review focuses on animal studies examining the biological determinants influencing activity and potential implications to human. It appears that physical activity is influenced by a number of parameters. However, regardless of the parameter involved, body weight appears to play all underlying role in the regulation of activity. Furthermore, the regulation of activity associated with body weight appears to occur only after the animal achieves a critical weight. This suggests that activity levels are a consequence rather than a contributor to weight control. However, the existence of an inverse weight-activity relationship remains inconclusive. Confounding the results are the multi-factorial nature of physical activity and the lack of appropriate measuring devices. Furthermore, many determinants of body weight are closely interlocked making it difficult to determine whether a single, combination or interaction of factors is important for the regulation of activity. For example, diet-induced obesity, aging, lesions to tile ventral medial hypothalamus and genetics all produce hypoactivity. Providing a better understanding of the biological determinants involved in the regulation of activity has important implications for the development of strategies for the prevention of weight gain leading to obesity and subsequent morbidity and mortality in the human population.
Document ID
20020059587
Acquisition Source
Johnson Space Center
Document Type
Preprint (Draft being sent to journal)
Authors
Tou, Janet C. L.
(Lockheed Martin Sciences and Engineering Moffett Field, CA United States)
Wade, Charles E.
(NASA Ames Research Center Moffett Field, CA United States)
Dalton, Bonnie P.
Date Acquired
September 7, 2013
Publication Date
January 1, 2001
Subject Category
Life Sciences (General)
Funding Number(s)
CONTRACT_GRANT: NAG9-1162
PROJECT: RTOP 121-10-30
PROJECT: RTOP 121-10-40
PROJECT: RTOP 121-10-50
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
No Preview Available