Obesity
Letter to the Editor PEDIATRIC OBESITY
Response to “Are the Results Likely Biased Toward the Null?” Alison E. Field1,2,3 and Carlos A. Camargo2,3,4 TO THE EDITOR: Dr. Lewis’ Letter-tothe-Editor, “Are the results likely biased toward the null?,” suggests that children may perceive sports drinks to be “healthful” and, therefore, over-report them due to a social desirability bias. Because the letter does not include any references to support this hypothesis, we searched the sparse literature on perceptions of (and reasons for) consuming sports drinks. More studies have investigated supplements and energy drinks, but O’Dea conducted a qualitative study of 78 adolescents who reported that the reasons for consumption of sports drinks were “thirst, taste, soft drink substitute, energy, sports performance, coaches preferences, and to prevent cramps” (1). While “health” was listed as a reason for consuming vitamins and minerals, it was not reported for sports drinks. While this one small study is far from conclusive, the results do not support Lewis’ hypothesis that children and adolescents consider sports drinks to be “healthful.” Moreover, a clinical report from the American Academy of Pediatrics concluded that “frequent or excessive intake of caloric sports drinks can substantially increase the risk for overweight or obesity
www.obesityjournal.org
in children and adolescents” (2). In other words, a major professional society endorses the view that health promotion is based on limiting, rather than increasing, intake sports drinks among adolescents. An equally important point is that we wrote that “there may be some measurement error, that likely bias the results toward the null” (3). Contrary to Lewis’ interpretation, we did not state that all intakes were underestimated. We believe that some youth will over-report their intake while others will underestimate their intake. Several validation studies have shown that the misclassification on a FFQ results in moderate to severe underestimation of associations with disease (i.e., bias toward the null) (4,5), thus it is reasonable to assume that our results may have been attenuated due to using a Food Frequency Questionnaire. We concur with Lewis’ that future research should seek to understand youth’s perceptions about sports drinks and other beverages. However, the lack of better knowledge about why adolescents consume sports drinks should not deter us from counseling that sports drinks have the potential to promote weight gain. These products were developed to counteract the profuse sweating of athletes engaging in at least 60 continuous minutes of activity. For most youth today, there is no health benefit to consuming sports drinks. On the contrary, our study adds to growing evidence of adverse
health consequences, gain.O
including
weight
C 2014 The Obesity Society V
References 1. O’Dea JA. Consumption of nutritional supplements among adolescents: usage and perceived benefits. Health Educ Res 2003;18:98-107. 2. Committee on Nutrition and the Council on Sports Medicine and Fitness. Sports drinks and energy drinks for children and adolescents: are they appropriate? Pediatrics 2011;127:1182-1189. 3. Field AE, Sonneville KR, Falbe J, et al. Association of sports drinks with weight gain among adolescents and young adults. Obesity 2014 Jul 14. doi: 10.1002/ oby.20845. 4. Schatzkin A, Kipnis V, Carroll RJ, et al. A comparison of a food frequency questionnaire with a 24-hour recall for use in an epidemiological cohort study: results from the biomarker-based observing protein and energy nutrition (OPEN) study. Int J Epidemiol 2003;32:1054-1062. 5. Kipnis V, Subar AF, Midthune D, et al. Structure of dietary measurement error: results of the OPEN biomarker study. Am J Epidemiol 2003;158:14-21. 1 Division of Adolescent Medicine, Department of Medicine, Boston Children’s Hospital and Harvard Medical School, Boston, Massachusetts, USA. Correspondence: Alison E. Field ([email protected]) 2 Channing Division of Network Medicine, Department of Medicine, Brigham and Women’s Hospital and Harvard Medical School, Boston, Massachusetts, USA. 3 Department of Epidemiology, Harvard School of Public Health, Boston, Massachusetts, USA. 4 Department of Emergency Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA.
doi: 10.1002/oby.20864
Obesity | VOLUME 22 | NUMBER 11 | NOVEMBER 2014
2327
Letter to the Editor PEDIATRIC OBESITY
Response to “Are the Results Likely Biased Toward the Null?” Alison E. Field1,2,3 and Carlos A. Camargo2,3,4 TO THE EDITOR: Dr. Lewis’ Letter-tothe-Editor, “Are the results likely biased toward the null?,” suggests that children may perceive sports drinks to be “healthful” and, therefore, over-report them due to a social desirability bias. Because the letter does not include any references to support this hypothesis, we searched the sparse literature on perceptions of (and reasons for) consuming sports drinks. More studies have investigated supplements and energy drinks, but O’Dea conducted a qualitative study of 78 adolescents who reported that the reasons for consumption of sports drinks were “thirst, taste, soft drink substitute, energy, sports performance, coaches preferences, and to prevent cramps” (1). While “health” was listed as a reason for consuming vitamins and minerals, it was not reported for sports drinks. While this one small study is far from conclusive, the results do not support Lewis’ hypothesis that children and adolescents consider sports drinks to be “healthful.” Moreover, a clinical report from the American Academy of Pediatrics concluded that “frequent or excessive intake of caloric sports drinks can substantially increase the risk for overweight or obesity
www.obesityjournal.org
in children and adolescents” (2). In other words, a major professional society endorses the view that health promotion is based on limiting, rather than increasing, intake sports drinks among adolescents. An equally important point is that we wrote that “there may be some measurement error, that likely bias the results toward the null” (3). Contrary to Lewis’ interpretation, we did not state that all intakes were underestimated. We believe that some youth will over-report their intake while others will underestimate their intake. Several validation studies have shown that the misclassification on a FFQ results in moderate to severe underestimation of associations with disease (i.e., bias toward the null) (4,5), thus it is reasonable to assume that our results may have been attenuated due to using a Food Frequency Questionnaire. We concur with Lewis’ that future research should seek to understand youth’s perceptions about sports drinks and other beverages. However, the lack of better knowledge about why adolescents consume sports drinks should not deter us from counseling that sports drinks have the potential to promote weight gain. These products were developed to counteract the profuse sweating of athletes engaging in at least 60 continuous minutes of activity. For most youth today, there is no health benefit to consuming sports drinks. On the contrary, our study adds to growing evidence of adverse
health consequences, gain.O
including
weight
C 2014 The Obesity Society V
References 1. O’Dea JA. Consumption of nutritional supplements among adolescents: usage and perceived benefits. Health Educ Res 2003;18:98-107. 2. Committee on Nutrition and the Council on Sports Medicine and Fitness. Sports drinks and energy drinks for children and adolescents: are they appropriate? Pediatrics 2011;127:1182-1189. 3. Field AE, Sonneville KR, Falbe J, et al. Association of sports drinks with weight gain among adolescents and young adults. Obesity 2014 Jul 14. doi: 10.1002/ oby.20845. 4. Schatzkin A, Kipnis V, Carroll RJ, et al. A comparison of a food frequency questionnaire with a 24-hour recall for use in an epidemiological cohort study: results from the biomarker-based observing protein and energy nutrition (OPEN) study. Int J Epidemiol 2003;32:1054-1062. 5. Kipnis V, Subar AF, Midthune D, et al. Structure of dietary measurement error: results of the OPEN biomarker study. Am J Epidemiol 2003;158:14-21. 1 Division of Adolescent Medicine, Department of Medicine, Boston Children’s Hospital and Harvard Medical School, Boston, Massachusetts, USA. Correspondence: Alison E. Field ([email protected]) 2 Channing Division of Network Medicine, Department of Medicine, Brigham and Women’s Hospital and Harvard Medical School, Boston, Massachusetts, USA. 3 Department of Epidemiology, Harvard School of Public Health, Boston, Massachusetts, USA. 4 Department of Emergency Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA.
doi: 10.1002/oby.20864
Obesity | VOLUME 22 | NUMBER 11 | NOVEMBER 2014
2327
