Research and Evaluation

 

The Physical Activity and Obesity Epidemiology Laboratory was established in August 2007, and we are currently investing in establishing ourselves in the research community at the Pennington Biomedical Research Center. We have several on-going collaborations on large-scale epidemiological investigations. The summaries below describe some of our recent research activities.

 

Pennington Center Longitudinal Study (PCLS) 

The PCLS draws its data from screening and study-specific information contained in the central PBRC clinic database and the bio-repository. These data have been collected over the last twenty years during the clinical research studies conducted at PBRC. The existing PCLS cross-sectional dataset represents an extract of the central clinic database that has undergone further data management to identify unique individuals and establish a baseline that maximizes the currently available data. The PCLS represents an effort to utilize the data collected on research volunteers to develop a cohort that can be used for cross-sectional analyses and can be followed prospectively for the development of a variety of health-related outcomes.

Selected Publications

Camhi S.M. and P.T. Katzmarzyk. Physical activity and bone mineral density in a sample of adults. Applied Physiology, Nutrition and Metabolism (In Press: Accepted for Publication on April 27, 2012).


Barreira T.V., D.M. Harrington, A.E. Staiano, S.B. Heymsfield, S.R. Smith and P.T. Katzmarzyk. Anthropometric correlates of total body fat, abdominal adiposity and cardiovascular disease risk factors in a biracial sample of men and women. Mayo Clinic Proceedings 2012;87:452-460.

Barreira T.V., D.M. Harrington, A.E. Staiano, S.B. Heymsfield and P.T. Katzmarzyk. Body adiposity index, body mass index and body fat in white and black adults. Journal of the American Medical Association (JAMA) 2011;306:828-830.

Katzmarzyk P.T., T.V. Barreira, D.M. Harrington, A.E. Staiano, S.B. Heymsfield and J.M. Gimble. Relationship between abdominal fat and bone mineral density in white and African American adults. Bone 2012; 50:576-579.


Newton Jr., R.L., C. Bouchard, G.A. Bray, F.L. Greenway, W.D. Johnson, E. Ravussin, D.H. Ryan and P.T. Katzmarzyk. Abdominal adiposity depots are correlates of adverse cardiometabolic risk factors in Caucasian and African American adults. Nutrition and Diabetes Nutrition and Diabetes 2011; 1: e2; doi:10.1038/nutd.2010.2.


Hu G., C. Bouchard, G.A. Bray, F.L. Greenway, W.D. Johnson, R.L. Newton, E. Ravussin, D.H. Ryan and P.T. Katzmarzyk. Trunk versus extremity adiposity and cardiometabolic risk factors in white and African American adults. Diabetes Care 2011;34:1415-1418.


Katzmarzyk P.T., G.A. Bray, F.L. Greenway, W.D. Johnson, R.L. Newton, Jr., E. Ravussin, D.H. Ryan, and C. Bouchard. Ethnic-specific body mass index and waist circumference thresholds. Obesity 2011;19:1272-1278.


Broyles S.T., C. Bouchard, G.A. Bray, F.L. Greenway, W.D. Johnson, R.L. Newton, Jr., E. Ravussin, D.H. Ryan, S.R. Smith and P.T. Katzmarzyk. Consistency of fat to fat-free mass relationship across race and sex groups. British Journal of Nutrition 2011;105:1272-1276.


Camhi S.M., G.A. Bray, C. Bouchard, F.L. Greenway, W.D. Johnson, R.L. Newton, Jr., E. Ravussin, D.H. Ryan, S.R. Smith and P.T. Katzmarzyk. The relationship of waist circumference and BMI to visceral, subcutaneous, and total body fat: Sex and race differences. Obesity 2011;19:402-408.


Sullivan R., W.D. Johnson and P.T. Katzmarzyk. Waist circumference is an independent correlate of errors in self-reported body mass index. Obesity 2010;11:2237-2239.


Katzmarzyk P.T., G.A. Bray, F.L. Greenway, W.D. Johnson, R.L. Newton, Jr., E. Ravussin, D.H. Ryan, S.R. Smith and C. Bouchard. Racial differences in depot-specific adiposity in white and African American adults. American Journal of Clinical Nutrition 2010;91:7-15.


Johnson W., C. Bouchard, R. Newton, Jr., D. Ryan and Katzmarzyk P.T. Ethnic differences in self-reported and measured obesity. Obesity 2009;17:571-577.

  

Canadian Physical Activity Longitudinal Study (PALS)

PALS is a cohort study of individuals aged 15 years and older who originally participated in the nationally representative 1981 Canada Fitness Survey and/or the 1988 Campbell’s Survey of Well-Being in Canada. Participant information was used to match to the Canadian Mortality Database in 1994, and participants were traced and sent a follow-up self-administered questionnaire pertaining to a variety of health-related topics between 2002 and 2004. We are currently investigating the role of physical activity and obesity in the prevention of chronic disease and premature mortality in this cohort, which has now been followed for 20 years.

Selected Publications

 

Mason C., C.L. Craig, L. Gauvin and P.T. Katzmarzyk. Opposing effects of waist and extremity circumferences on the risk of incident diabetes. Canadian Journal of Diabetes 2009;33:85-91

Katzmarzyk P.T., T.S. Church, C.L. Craig and C. Bouchard. Sitting time and mortality from all causes, cardiovascular disease, and cancer. Medicine and Science in Sports and Exercise 2009;41:998-1005.

 

Herman K.M., C.L. Craig, L. Gauvin and P.T. Katzmarzyk. Tracking of obesity and physical activity from childhood to adulthood: The Physical Activity Longitudinal Study. International Journal of Pediatric Obesity 2009; 4:281-288. .

 

Barnett T.A., L. Gauvin, C.L. Craig, and P.T. Katzmarzyk. Distinct trajectories of leisure time physical activity in adults and predictors of trajectory class membership: a 22 year cohort study. International Journal of Behavioural Nutrition and Physical Activity 2008; 5:57 (E-Pub).

 

Mason C., C.L. Craig and P.T. Katzmarzyk. Influence of central and extremity circumferences on all-cause mortality in men and women. Obesity 2008;16:2690-2695.

 

Mason C., P.T. Katzmarzyk, C.L. Craig and L. Gauvin. Mortality and self-rated health in Canada. Journal of Physical Activity and Health 2007;4:423-433.

 

Katzmarzyk P.T., C.L. Craig and L. Gauvin. Adiposity, physical fitness and incident diabetes: The Physical Activity Longitudinal Study. Diabetologia 2007;50:538.

 

Brien S., P.T. Katzmarzyk, C.L. Craig and L. Gauvin. Physical activity, cardiorespiratory fitness and body mass index as predictors of substantial weight gain and obesity: The Canadian Physical Activity Longitudinal Study. Canadian Journal of Public Health 2007;98:121-124.

 

Barnett T.A., L. Gauvin, C.L. Craig and P.T. Katzmarzyk. Modifying effects of sex, age, and education on 22-Year trajectory of leisure-time energy expenditure in a Canadian cohort. Journal of Physical Activity and Health 2007;4: 153-166.

 

Mason C., S. Brien, C.L. Craig, L. Gauvin and P.T. Katzmarzyk. Musculoskeletal fitness and weight gain in Canada. Medicine and Science in Sports and Exercise 2007;39:38-43.

 

Katzmarzyk P.T. and C.L. Craig. Independent effects of waist circumference and physical activity on risk of all-cause mortality in Canadian women. Applied Physiology, Nutrition and Metabolism 2006;31:271-276.

 

Craig C.L., L. Gauvin, S. Cragg, P.T. Katzmarzyk, T.M. Stephens, S.J. Russell, L. Potvin, M. Keast and L. Bentz. Towards a social epidemiological perspective on physical activity and health: The aims, design, and methods of the Physical Activity Longitudinal Study (PALS). Journal of Physical Activity and Health 2005;3:272-284.

 

Katzmarzyk P.T., C.L. Craig and C. Bouchard.  Adiposity, adipose tissue distribution and mortality. International Journal of Obesity and Related Metabolic Disorders 2002;26:1054-1059.

 

Katzmarzyk P.T., C.L. Craig and C. Bouchard.  Underweight, overweight and obesity: Relationships with mortality in the 13-year follow-up of the Canada Fitness Survey. Journal of Clinical Epidemiology 2001;54:916-920.

 

Canadian Heart Health Surveys Follow-up Study

The Canadian Heart Health Surveys (CHHS) is a compilation of 10 provincial, independently conducted surveys on cardiovascular risk factors, behavior and risk factor knowledge. Participants in the CHHS were selected from provincial medical insurance registries between 1986 and 1992, and a two-stage probability sampling scheme was used to ensure geographical, sex and age representativeness. Several cross-sectional studies have been published using data from the CHHS. We have recently linked the original CHHS data from five provinces to the Canadian Mortality Database (CMDB), with follow-up through December 31, 2004. This linkage was completed in 2009, and analyses of obesity, cardiovascular disease risk factor and mortality are in development. 

Selected Publications

Staiano A.E., B. Reeder, S. Elliott, M. Joffres, P. Pahwa, S. Kirkland, G. Paradis and P.T.
Katzmarzyk. Physical activity, obesity and mortality in the Canadian Heart Health Surveys
Mortality Follow-up Study. Applied Physiology, Nutrition and Metabolism (In Press: Accepted for
Publication on March 2, 2012)


Staiano A.E., B. Reeder, S. Elliott, M. Joffres, P. Pahwa, S. Kirkland, G. Paradis and P.T.
Katzmarzyk. Body mass index versus waist circumference as predictors of mortality in Canadian
adults. International Journal of Obesity and Related Metabolic Disorders 2012; Advance Online
Publication January 17, 2012.


Katzmarzyk P.T., B.A. Reeder, S. Elliott, M.R. Joffres, P. Pahwa, K.D. Raine, S.A. Kirkland and
G. Paradis. Body mass index and risk of cardiovascular disease, cancer and all-cause mortality.
Canadian Journal of Public Health 2012;103:147-151.


Brien S. and P.T. Katzmarzyk. Physical activity and the metabolic syndrome in Canada.
Applied Physiology, Nutrition and Metabolism 2006;31:40-47.


Mason C. and P.T. Katzmarzyk. Application of obesity treatment algorithms to Canadian
adults. European Journal of Clinical Nutrition 2005;59:797-800.


Ardern C.I., I. Janssen, R. Ross and P.T. Katzmarzyk. Development of health-related waist
circumference thresholds within BMI categories. Obesity Research 2004;12:1094-1103.

 

Bogalusa Heart Study

The Bogalusa Heart Study is a community-based investigation of the natural history of cardiovascular disease from childhood into adulthood.   Eligible participants were drawn from children and adolescents living in Ward 4 of Washington Parish in South East Louisiana, a bi-racial community (65% white, 35% black) of approximately 20,000 people.  Several cross-sectional surveys have been conducted between 1973 and 2002, and many individuals have participated in multiple surveys. A longitudinal cohort of participants in embedded into the cross-sectional surveys, allowing for the study of childhood risk factors and adult health outcomes. The Bogalusa Heart Study is administered by Dr. Gerald Berenson at the Tulane University Center for Cardiovascular Health. We have been collaborating with Dr. Berenson and the Bogalusa Heart Study investigators for several years.    

Selected Publications

Camhi S.M., P.T. Katzmarzyk, S.T. Broyles, S.R. Srinivasan, W. Chen, C. Bouchard and G.S.
Berenson. Subclinical atherosclerosis and metabolic risk: Role of BMI and waist circumference.
Metabolic Syndrome and Related Disorders 2011;9:119-125.


Freedman D.S., P.T Katzmarzyk, W.H. Dietz, S.R. Srinivasan and G.S. Berenson. The relation
of BMI and skinfold thicknesses to risk factors among young and middle-aged adults: The
Bogalusa Heart Study. Annals of Human Biology 2010;37:726-737.


Broyles S.T., P.T. Katzmarzyk, S.R. Srinivasan, W. Chen, C. Bouchard, D.S. Freedman and
G.S. Berenson. The pediatric obesity epidemic continues unabated in Bogalusa, Louisiana.
Pediatrics 2010; 125:900-905.


Camhi S.M., P.T. Katzmarzyk, S. Broyles, S.R. Srinivasan, W. Chen, C. Bouchard and G.S.
Berenson. Predicting adult BMI-specific cardiometabolic risk from childhood. Metabolic
Syndrome and Related Disorders 2010;8:165-172.


Freedman D.S., P.T. Katzmarzyk, W.H. Dietz, S.R Srinivasan, and G.S. Berenson. The
relation of BMI and skinfold thicknesses to cardiovascular disease risk factors among
children: The Bogalusa Heart Study. American Journal of Clinical Nutrition. 2009; 90:210-216.


Sisson S.B., P.T. Katzmarzyk, S.R. Srinivasan, W. Chen, D. Freedman, C. Bouchard and G.S. Berenson. Ethnic differences in BMI, subcutaneous fat and waist girth in children and youth. Obesity 2009; 17:2075-2081.


Janssen I., P.T. Katzmarzyk, S. R. Srinivasan, W. Chen, R.M. Malina, C. Bouchard and G.S. Berenson. The clinical utility of childhood body mass index in the prediction of adult disease: Comparison of national reference and international guidelines. Obesity Research 2005;13:1106-1115.


Janssen I., P.T. Katzmarzyk, S. R. Srinivasan, W. Chen, R.M. Malina, C. Bouchard and G.S. Berenson. Combined influence of the body mass index and waist circumference on coronary heart disease risk factors in children and adolescents. Pediatrics 2005;155:1623-1630.


Katzmarzyk P.T., S. R. Srinivasan, W. Chen, R.M. Malina, C. Bouchard and G.S. Berenson. Body mass index, waist circumference, and clustering of cardiovascular disease risk factors in a biracial sample of children and adolescents. Pediatrics 2004;114:e198-e205.

 

National Health and Nutrition Examination Survey (NHANES) 

NHANES began in the early 1960s as a series of health surveys that became continuous in its implementation since 1999.  A nationally representative sample of approximately 5,000 people is surveyed each year, using a combination of interviews and physical examinations. NHANES uses a complex, multistage, probability sampling design to select participants representative of the civilian, non-institutionalized U.S. population. Oversampling of certain population subgroups (i.e., African Americans, Mexican Americans, low income European Americans, adolescents 12-19 years, and people over 60 years) is done to increase the reliability and precision of health status indicator estimates for these groups. Each individual in the NHANES is assigned a sample weight based on census population figures; this allows for the development of national prevalence estimates.

Selected Publications

Barreira T.V., P.T. Katzmarzyk, W.D. Johnson and C. Tudor-Locke. Cadence patterns and peak cadence in U.S. children and adolescents: NHANES, 2005-2006. Medicine and Science in Sports and Exercise 2012; Advance Online Publication March 26, 2012.


Katzmarzyk P.T. and I.-M. Lee. Sedentary behavior and life expectancy in the United States. BMJ Open (In Press: Accepted for Publication on February 13, 2012).


Tudor-Locke C., M. Brashear, P.T. Katzmarzyk and W.D. Johnson. Peak stepping cadence in free-living adults: 2005-2006 NHANES. Journal of Physical Activity and Health 2012; Advance Online Publication December 27, 2011.


Sisson S.B., S.M. Camhi, C, Tudor-Locke, W.D. Johnson and P.T. Katzmarzyk. Characteristics of step-determined physical activity categories in U.S. adults. American Journal of Health Promotion 2012;26:152-159.


Tudor-Locke C., S.M. Camhi, C. Leonardi, W.D. Johnson, P.T. Katzmarzyk, C.P. Earnest and T.S. Church. Patterns of adult stepping cadence in the 2005-2006 NHANES. Preventive Medicine 2011; 53:178-181.


Church T.S., D.M. Thomas, C. Tudor-Locke, P.T. Katzmarzyk, C.P. Earnest, R.Q. Rodarte, C.K. Martin, S.N. Blair and C. Bouchard. Trends over 5 decades in U.S. occupation-related physical activity and their associations with obesity. PLoS ONE 2011;6(5):e19657.


Camhi S.M., S.B. Sisson, W.D. Johnson, P.T. Katzmarzyk and C. Tudor-Locke. Accelerometer-determined lifestyle physical activities in U.S. adults. Journal of Physical Activity and Health 2011;8:382-389.


Tudor-Locke C., W.D. Johnson and P.T. Katzmarzyk. Relationship between accelerometer-determined steps/day and other accelerometer outputs in U.S. adults Journal of Physical Activity and Health 2011;8:410-419.


Camhi, S.M. and P.T. Katzmarzyk. Prevalence of cardiometabolic risk factor clustering and body mass index in adolescents. Journal of Pediatrics 2011;159:303-307.


Tudor-Locke C., C. Leonardi, W.D. Johnson, P.T. Katzmarzyk and T.S. Church. Accelerometer-determined steps/day translation to moderate-to-vigorous physical activity. Preventive Medicine 2011;53:31-33.


Tudor-Locke C., W.D. Johnson and P.T. Katzmarzyk. U.S. population profile of time-stamped accelerometer outputs: Impact of wear time. Journal of Physical Activity and Health 2011:8:693-698.


Tudor-Locke C., M.M. Brashear, W.D. Johnson and P.T. Katzmarzyk. Accelerometer profiles in normal weight, overweight, and obese U.S. men and women. International Journal of Behavioral Nutrition and Physical Activity 2010;7:60.


Tudor-Locke C., W.D. Johnson and P.T. Katzmarzyk. Accelerometer-determined steps/day in U.S. children and youth. Medicine and Science in Sports and Exercise 2010;42:2244-2250.


Sisson S.B., S.M. Camhi, T.S. Church, C. Tudor-Locke, W.D. Johnson and P.T. Katzmarzyk. Accelerometer-determined steps/day and metabolic syndrome. American Journal of Preventive Medicine 2010;38:575-582.


Sisson S.B., S.M. Camhi, T.S. Church, C.K. Martin, C. Tudor-Locke, S.R. Smith, C. Bouchard, C.P. Earnest, T. Rankinen, R.L. Newton and P.T. Katzmarzyk. Leisure-time sedentary behavior and metabolic disease risk in U.S. men and women: National Health and Nutrition Examination Survey 2003-2006. Metabolic Syndrome and Related Disorders 2009;7:529-536.


Sisson S.B., T.S. Church, C.K. Martin, C. Tudor-Locke, S.R. Smith, C. Bouchard, C.P. Earnest, T. Rankinen, R. Newton, Jr. and P.T. Katzmarzyk. Profiles of sedentary behavior in children and adolescents: The U.S. National Health and Nutrition Examination Survey, 2001-2006. International Journal of Pediatric Obesity. 2009; 1-7.


Tudor-Locke C., W.D. Johnson and P.T. Katzmarzyk. Accelerometer-determined steps/day in U.S. adults. Medicine and Science in Sports and Exercise 2009; 41:1384-1391.


Johnson, W.D., J. Kroon, F.L. Greenway, C. Bouchard, D. Ryan and P.T. Katzmarzyk. Prevalence of component risk factors for the metabolic syndrome in adolescents; NHANES 2001-2006. Archives of Pediatrics and Adolescent Health 2009;163:371-377.


Brien S., I. Janssen and P.T. Katzmarzyk. Physical fitness and metabolic syndrome: U.S. National Health and Nutrition Examination Survey 1999-2002. Applied Physiology, Nutrition and Metabolism 2007;32:143-147.


Ardern C.I., I. Janssen, R. Ross and P.T. Katzmarzyk. Development of health-related waist circumference thresholds within BMI categories. Obesity Research 2004;12:1094-1103.


Janssen I., P.T. Katzmarzyk and R. Ross. Duration of overweight and metabolic health risk in American men and women. Annals of Epidemiology 2004;14:585-591.


Janssen I., P.T. Katzmarzyk and R. Ross. Waist circumference and not body mass index explains obesity-related health risk. American Journal of Clinical Nutrition 2004;79:379-384.


Janssen I., P.T. Katzmarzyk and R. Ross. Body mass index, waist circumference and health risk: Evidence in support of current NIH guidelines. Archives of Internal Medicine 2002;162:2074-2079.

 

Anthropometric Assessment of Abdominal Obesity and Health Risk in Children and Adolescents

 

Abdominal fat, in particular intra-abdominal visceral adipose tissue, is considered to be the most dyslipidemic and atherogenic fat depot in the human body. Intra-abdominal visceral adipose tissue and total body fat can be measured precisely and reliably in a laboratory setting using advanced imaging techniques; however, reliable clinical measurements of pediatric intra-abdominal visceral adipose tissue and total body fat are yet to be developed. Thus, the specific aims of this study are to 1) identify reliable landmarks and methodology for the measurement of pediatric waist circumference that are associated with intra-abdominal visceral adipose tissue and total body fat across the pediatric age, total body adiposity, and maturity range among African American and Caucasian children and adolescents, 2) determine if waist circumference in combination with other anthropometric indices is a better predictor of intra-abdominal visceral adipose tissue and total body fat than waist circumference alone across the pediatric age, total body adiposity, and maturation range, and 3) develop and determine the clinical utility of pediatric race-sex-specific waist circumference thresholds for the identification of elevated chronic disease risk factors across the pediatric age, total body adiposity, and maturation range. We will accomplish these aims by conducting a cross-sectional study of 100 African American boys, 100 Caucasian boys, 100 African American girls, and 100 Caucasian girls 5 to 18 years of age. Waist circumference will be measured at the four common anatomic sites used in pediatric research: 1) superior border of the iliac crest, 2) midpoint between the iliac crest and the lowest rib, 3) umbilicus, and 4) minimal waist. Additional body dimensions will be obtained in order to determine the clinical utility of combining waist circumference with other measurements in predicting intra-abdominal visceral adipose tissue and total body fat, which will be assessed using advanced imaging techniques. The identification of the most appropriate waist circumference landmarks and measurement techniques is important for the clinical identification of children at elevated obesity-related health risk and for the standardization of obesity surveillance strategies within and between countries.  This study is funded by the U.S. National Institutes of Health.

Selected Publications

Broyles S.T., A.E. Staiano, K.T. Drazba, and P.T. Katzmarzyk. Household clustering of excessive television viewing time in youth. International Society for Behavioural Nutrition and Physical Activity. Austin TX, May, 2012.


Staiano A.E., S.T. Broyles, A.K. Gupta and P.T. Katzmarzyk. Physical activity relates to lower visceral adiposity in children and adolescents. Joint Conference - 52nd Cardiovascular Disease Epidemiology and Prevention and Nutrition, Physical Activity and Metabolism, American Heart Association, San Diego, CA, March, 2012.


Staiano A.E., S.T. Broyles, A.K. Gupta and P.T. Katzmarzyk. Sexual maturation independently contributes to adiposity differences between African American and Caucasian girls. Joint Conference - 52nd Cardiovascular Disease Epidemiology and Prevention and Nutrition, Physical Activity and Metabolism, American Heart Association, San Diego, CA, March, 2012.


Broyles S.T., A.E. Staiano, K.T. Drazba, A.K. Gupta and P.T. Katzmarzyk. Neighborhood crime and poverty and systemic inflammation in children. Joint Conference - 52nd Cardiovascular Disease Epidemiology and Prevention and Nutrition, Physical Activity and Metabolism, American Heart Association, San Diego, CA, March, 2012.


Staiano A.E., S.T. Broyles, A.K. Gupta and P.T. Katzmarzyk. Ethnic differences in visceral and subcutaneous adiposity in children and adolescents. Obesity 2011;(Supplement) Annual Meetings of the Obesity Society, Orlando, FL, October, 2011.


Harrington D.M., A.E. Staiano, S.T. Broyles, A. Gupta and P.T. Katzmarzyk. Comparison of waist circumference measured at different anatomic sites with depot-specific adiposity in children. Obesity 2011;(Supplement) Annual Meetings of the Obesity Society, Orlando, FL, October, 2011.


Staiano A.E., S.T. Broyles, A.K. Gupta and P.T. Katzmarzyk. Daily screen time and visceral and subcutaneous adiposity in children and adolescents. Obesity 2011;(Supplement) Annual Meetings of the Obesity Society, Orlando, FL, October, 2011.

 

 InSight

 

Dietary intervention and other strategies to prevent unhealthy weight gain and the development of obesity should be based on knowledge of dietary, physiological, genetic, and behavioral determinants and their contributing interactions.  Identifying these determinants is difficult because physiological susceptibility to specific dietary and behavioral factors implicated in unhealthy weight gain differs between populations and among individuals within populations.  The research challenge is identifying specific determinants in a free-living, U.S. adult population. InSight is a prospective longitudinal study of  free-living normal weight adults aged 20-35 at baseline. The primary aim of InSight is to identify the most important determinants of weight gain and the development of overweight and obesity.  As a secondary aim, we will identify a single parsimonious collection of factors and develop strategies to mitigate the risks of developing obesity. The sample is equally divided by sex and race (white and African American). The participants are undergoing a series of assessments in the domains of diet, physiology, genetics, and behavior at baseline and will return every 12 months for 10 years. Advanced longitudinal and multivariate statistical and epidemiologic techniques will be used to identify and model underlying correlation structures among the measurements collected by the research team pertaining to diet (dietary intake of fat, sugar-sweetened beverages, calcium, and fiber, and portion size) physiological factors (energy expenditure, insulin sensitivity and secretion, detailed body composition, skeletal muscle metabolism, adipocyte factors), genetic factors (sensory perception and candidate genes), behavioral factors (dietary restraint, disinhibition, food neophobia, sedentary behavior, and physical activity), demographics, and other possible contributing factors to unhealthy weight gain over time. 

Selected Publications

Harrington D.M., C.K. Martin, E. Ravussin, J. Rood, D. Shepard, S.R. Smith and P.T. Katzmarzyk . Physical activity energy expenditure and measures of hunger and satiety. Obesity 2011;(Supplement) Annual Meetings of the Obesity Society, Orlando, FL, October, 2011.

 

Delta Obesity Prevention Research

Reducing the high and increasing prevalence of obesity is a federal priority. The current high levels of obesity are taking a staggering toll on public and personal health in the USA. The Pennington Biomedical Research Center is part of a research consortium that includes multiple universities in Louisiana, Mississippi, and Arkansas. The mission of this consortium is to conduct nutrition research to prevent obesity in at-risk, rural populations in the Lower Mississippi Delta of Arkansas, Louisiana, and Mississippi. The Agricultural Research Service (ARS) is coordinating this major research endeavor that brings together the talents of ARS and other research cooperators in the tri-state region with the ultimate goal of promoting optimal health and reducing the burden of obesity in this population. USDA funding for this research initiative at PBRC has been continuous since 1998. The partner institutions include the Pennington Biomedical Research Center, Southern University and A&M College, Baton Rouge, LA; University of Southern Mississippi, Alcorn State University, MS; University of Arkansas Pine Bluff, Arkansas Children’s Hospital Research Institute, AR; Delta NIRI Executive Office, AR. The current USDA funded project at PBRC is aimed at increasing physical activity among residents of the Lower Mississippi Delta. This project is being conducted in two phases. During Phase I we will determine the feasibility of adapting physical activity recommendations by incorporating pedometers (step-counters) as self-monitoring tools within the context of an education program. Specifically, participants will be instructed to achieve DG physical activity recommendations and monitor the number of steps they take congruent with this success. Lessons learned from the feasibility study will be incorporated into the design of Phase II, in which we will conduct a properly powered, randomized controlled effectiveness trial of physical activity and adapted DG eating patterns to reduce unhealthy weight gain. An expectation from the short-term nature of the feasibility study is an immediate increase in physical activity (both number of steps and time in moderate to vigorous activity as assessed by accelerometer) based on the adopted use of a pedometer. The Phase II study will determine if the implementation of these newly identified step-based physical activity recommendations can be used directly to achieve and sustain recommended levels of physical activity in the Lower Mississippi Delta population. 

Selected Publications

 

Barreira T.V., C. Tudor-Locke, C.M. Champagne, S.T. Broyles, D. Harsha, B.M. Kennedy, W.D. Johnson, Ray Allen and P.T. Katzmarzyk. Comparison of YAMAX pedometer and GT3X accelerometer steps/day in a free-living sample of overweight and obese adults. Journal of Physical Activity and Health (In Press: Accepted for Publication on December 13, 2011).


Katzmarzyk P.T., C.M. Champagne, C. Tudor-Locke, S.T. Broyles, D. Harsha, B.M. Kennedy and W.D. Johnson. A short-term physical activity randomized trial in the Lower Mississippi Delta. PloS ONE 2011;6(10):e26667. doi:10.1371/journal.pone.0026667.


Harrington D.M., C. Tudor-Locke, C.M. Champagne, S.T. Broyles, D. Harsha, B.M. Kennedy, W.D. Johnson, R. Allen and P.T. Katzmarzyk. Step-based translation of physical activity guidelines in the Lower Mississippi Delta. Applied Physiology, Nutrition and Metabolism 2011;36:583-585.

  

Evaluation of the Louisiana Tobacco Control Program

 

The Pennington Biomedical Research Center is funded from 2010 to 2012 through the Louisiana Department of Health and Hospitals, to serve as the external evaluator of the Louisiana Tobacco Control Program (LTCP). This will provide the LTCP with performance measurements and guidelines to effectively meet and surpass the goals and objectives of a variety of projects, partnerships, and policies aimed at promoting a Tobacco-Free Louisiana.  Key areas of evaluation include on-going efforts with community partners to promote Tobacco-Free Schools and reduce initiation of tobacco use among Louisiana’s youth; reduce exposure to secondhand smoke in workplaces and public spaces; assist individuals with the challenges of tobacco cessation through Quitlines and Fax-to-Quitlines; reduce tobacco-related disparities among vulnerable populations. Evaluation efforts will also include CDC’s recently created Communities Putting Prevention to Work program through which ARRA funds will be used to enhance this wellness agenda by specifically targeting school age youth through grants to public school districts, and underserved pregnant women through maternal and child healthcare providers and media campaigns.