The Journal of Nutrition Letters to the Editor
Association of Soft Drink Consumption with Increased Waist Circumference Should Be Adjusted for Body Mass Index Dear Editor:
1370
Author disclosures: P Traissac, J El Ati, A Gartner, Y Martin-Pre´vel, and F Delpeuch, no conflicts of interest.
Pierre Traissac Jalila El Ati Agne`s Gartner Yves Martin-Pre´vel Francis Delpeuch From the IRD (Institute of Research for Development), NUTRIPASS Research Unit (Population Nutrition in Southern Countries), Montpellier, France (PT, e-mail: [email protected], AG, YM-P, FD); and National Institute of Nutrition and Food Technology and Nutrition Surveillance and Epidemiology in Tunisia Research Laboratory, Tunis, Tunisia (JEA). ã 2015 American Society for Nutrition. J Nutr 2015;145:1370–2.
Downloaded from jn.nutrition.org at UNIV OF CALIFORNIA SAN DIEGO on June 5, 2015
We were very interested in the recent article by Funtikova et al. (1) entitled “Soft Drink Consumption Is Positively Associated with Increased Waist Circumference and 10-Year Incidence of Abdominal Obesity in Spanish Adults.” Their study, which was conducted in the city of Gerona, deals with a major public health issue and has a number of methodologic strengths including a prospective design with a high rate of follow-up, use of a validated FFQ for assessment of the main exposure, and careful control of confounding by other lifestyle factors, as well as the use of advanced statistical methods, including spline regression to assess associations, all highly commendable features. Nevertheless, we would like to point to a few issues regarding the choice of the main outcome in the analyses presented in the article. First, although the use of anthropometric proxies is standard in large-scale field studies, it is well documented that the use of waist circumference (WC) as a proxy for abdominal adiposity has its limits, and these should have been acknowledged more. One such limit is that WC does not distinguish between different types of abdominal fat accumulation, e.g., visceral vs. subcutaneous adipose tissues, which may be differently associated with adverse health outcomes (2, 3). This would be an interesting topic for discussion, especially when studying the specific association of soft drink consumption with central obesity (4). There are also technical difficulties involved in measuring WC in the field, especially among overweight or obese subjects, and these could also have been acknowledged (5). For example, the WHO recommends measuring WC in millimeters, rather than to the nearest 0.5 cm, as performed by Funtikova et al. (1). Although WC is a good predictor of cardiovascular disease risk, there also may be other reliable anthropometric proxies of abdominal adiposity and it would be interesting to assess whether the same associations are observed (6). Most importantly, it would be interesting to investigate if the associations observed by Funtikova et al. (1) are specific to abdominal adiposity (WC), or whether the same results would have been obtained using a proxy of overall adiposity such as BMI. Indeed, it is widely acknowledged that abdominal and overall adiposity in general and thus WC and, e.g., BMI, are extremely correlated. One consequence is that in many studies, similar associations with exposures are observed using either of these adiposity proxies. Unfortunately, the authors provide no data on the associations between the factors they studied and BMI either in the main text or in the extensive supplementary online material. Furthermore, as stated by the authors as one of the justifications for their study, it would seem that there is a current trend of increasing WC in all BMI categories and thus a growing discrepancy between the assessment of the burden of obesity using either abdominal or overall obesity (7–9). In addition, a number of authors consider that abdominal adiposity
is a better predictor of a variety of adverse health outcomes, including mortality risk (6), than a proxy of overall adiposity such as BMI. Thus, a major issue is being able to assess the factors involved in increased WC independently of increases in BMI. A number of studies deal with lifestyle correlates of WC (including the one we refer to here focused on association with soft drinks). But evidence of why people develop abdominal obesity independently of overall obesity is rare, although a few authors have put forward sedentary behavior, high energy intake, total and type of fat intake, alcohol intake, or lack of sleep as possible factors (10–12). Thus, a well-designed study such as that reported by the authors would seem to be an ideal instrument to disentangle the specific association of the exposure with increases in WC independently of increases in BMI from the association because of the strong correlation of WC with BMI. Adjusting WC for BMI is, indeed, not entirely straightforward statistically because of their strong correlation; however, there are a number of analytic modeling techniques [of which Funtikova et al. (1) are doubtless aware] available to achieve this goal, provided, of course, that height and weight data were available. Regarding height and weight, we assume they were measured because the Methods of the abstract does mention such measurements, but they are not listed in the anthropometrics paragraph of the article itself or referred to in the Results or Analyses, and there is only a very brief reference to the increase in prevalence of general obesity at the beginning of the Discussion. Thus, notwithstanding the merits of the results presented by Funtikova et al. (1), by adjusting the observed increase in WC associated with soft drink consumption for BMI, we believe the authors would have made an even more important contribution to the knowledge of why abdominal adiposity appears to be increasing more rapidly than BMI. This issue is indeed a major public health concern, especially in nutrition transition contexts where incidences of obesity are the highest and this discrepancy is especially worrisome.
References 1.
Author disclosures: H Schro¨der and A Funtikova, no conflicts of interest.
doi:10.3945/jn.115.211912.
Helmut Schro¨der Anna Funtikova
Reply to Traissac et al.
From the Cardiovascular Risk and Nutrition Research Group, Hospital del Mar Medical Research Institut (IMIM), Barcelona, Spain (HS, e-mail: [email protected], AF).
Dear Editor: We thank Traissac et al. for their interest in our recent report on the association between caloric beverage consumption, waist circumference (WC), and incidence of abdominal obesity (1) and appreciate the opportunity to respond to their comments. As Traissac et al. point out, abdominal adiposity measured by WC as a surrogate marker is a strong predictor for cardiometabolic health and mortality (2, 3). Furthermore, a recent study showed a greater utility of WC for identifying adults at cardiometabolic risk compared to BMI, fat mass, and percentage body fat (4). These findings, along with the high prevalence and marked increase of abdominal obesity in the population we
References 1.
2.
3.
Funtikova AN, Subirana I, Gomez SF, Fito´ M, Elosua R, Benı´tezArciniega AA, Schro¨der H. Soft drink consumption is positively associated with increased waist circumference and 10-year in cidence of abdominal obesity in Spanish adults. J Nutr 2015;145: 328–34. Zhang C, Rexrode KM, van Dam RM, Li TY, Hu FB. Abdominal obesity and the risk of all-cause, cardiovascular, and cancer mortality: sixteen years of follow-up in US women. Circulation 2008;117:1658–67. Fox KA, Despres JP, Richard AJ, Brette S, Deanfield JE. Does abdominal obesity have a similar impact on cardiovascular disease and diabetes? A study of 91,246 ambulant patients in 27 European countries. Eur Heart J 2009;30:3055–63.
Letters to the Editor
1371
Downloaded from jn.nutrition.org at UNIV OF CALIFORNIA SAN DIEGO on June 5, 2015
Funtikova AN, Subirana I, Gomez SF, Fito´ M, Elosua R, Benı´tezArciniega AA, Schro¨der H. Soft drink consumption is positively associated with increased waist circumference and 10-year incidence of abdominal obesity in Spanish adults. J Nutr 2015;145:328–34. 2. Demerath EW, Reed D, Rogers N, Sun SS, Lee M, Choh AC, Couch W, Czerwinski SA, Chumlea WC, Siervogel RM, et al. Visceral adiposity and its anatomical distribution as predictors of the metabolic syndrome and cardiometabolic risk factor levels. Am J Clin Nutr 2008;88: 1263–71. 3. Fox CS, Massaro JM, Hoffmann U, Pou KM, Maurovich-Horvat P, Liu CY, Vasan RS, Murabito JM, Meigs JB, Cupples LA, et al. Abdominal visceral and subcutaneous adipose tissue compartments: association with metabolic risk factors in the Framingham Heart Study. Circulation 2007; 116:39–48. 4. Maersk M, Belza A, Stodkilde-Jorgensen H, Ringgaard S, Chabanova E, Thomsen H, Pedersen SB, Astrup A, Richelsen B. Sucrosesweetened beverages increase fat storage in the liver, muscle, and visceral fat depot: a 6-mo randomized intervention study. Am J Clin Nutr 2012;95:283–9. 5. Mason C, Katzmarzyk PT. Variability in waist circumference measurements according to anatomic measurement site. Obesity (Silver Spring) 2009;17:1789–95. 6. Song X, Jousilahti P, Stehouwer CD, Soderberg S, Onat A, Laatikainen T, Yudkin JS, Dankner R, Morris R, Tuomilehto J, et al. Comparison of various surrogate obesity indicators as predictors of cardiovascular mortality in four European populations. Eur J Clin Nutr 2013;67:1298– 302. 7. Walls HL, Stevenson CE, Mannan HR, Abdullah A, Reid CM, McNeil JJ, Peeters A. Comparing trends in BMI and waist circumference. Obesity (Silver Spring) 2011;19:216–9. 8. Traissac P, Pradeilles R, El Ati J, Aounallah-Skhiri H, Eymard-Duvernay S, Gartner A, Be´ji C, Bougatef S, Martin-Prevel Y, Kolsteren P, et al. Abdominal vs. overall obesity among women in a nutrition transition context: geographic and socio-economic patterns of abdominal-only obesity in Tunisia. Popul Health Metr 2015;13:1. 9. Freedman DS, Ford ES. Are the recent secular increases in the waist circumference of adults independent of changes in BMI? Am J Clin Nutr 2015;101:425–31. 10. Chaput JP, Despre´s JP, Bouchard C, Tremblay A. Short sleep duration preferentially increases abdominal adiposity in adults: preliminary evidence. Clin Obes 2011;1:141–6. 11. Halkjaer J, Sorensen TI, Tjonneland A, Togo P, Holst C, Heitmann BL. Food and drinking patterns as predictors of 6-year BMI-adjusted changes in waist circumference. Br J Nutr 2004;92:735–48. 12. Wahlqvist ML, Hodgson JM, Ng FM, Hsu-Hage BH-H, Strauss BJ. The role of nutrition in abdominal obesity. Nutr Res 1999;19:85– 101.
studied (5), led to our decision to determine the impact of caloric beverage consumption on these outcomes, using WC as the indicator. Technical problems related to WC measurements in overweight or obese subjects certainly may occur but can be readily resolved if the personnel involved have received adequate training; we have found no reports showing a technical problem that results in a BMI category-specific bias. Generally, independent of the measurement protocol, WC measurement has shown excellent intra- and interobserver reliability (6, 7). We addressed this topic using several statistical models to ensure the consistency of our findings. In our opinion, the inclusion of other anthropometric measures as outcomes such as BMI, waist-to-height ratio, or WC adjusted for BMI (as the residuals of WC regressed on BMI) would have overloaded the manuscript. Therefore, although Traissac et al. are correct that we had access to additional measurements, we chose to focus on WC as a promising indicator that is often ignored in clinical practice. Although the present manuscript did not discuss any association between exposure and intra- or subcutaneous fat tissue, several other studies have shown that, of the 2 fat tissues, visceral adipose tissue has a stronger association, albeit in the same direction, with cardiovascular risk factors (8, 9). A recent intervention study in 47 overweight subjects used DXA and MRI to determine the effect of different beverages on fat distribution and other endpoints, finding a significant increase in visceral fat but not subcutaneous or total fat tissue after 6 mo of sucrose-sweetened soft drink consumption, compared to other beverages (10). Again, our study data were based on WC measurements; any discussion of the specific impact of soft drink consumption and different types of abdominal fat accumulation would have been speculative. We fully agree with Traissac et al. that the association of changes in abdominal adiposity independent of general adiposity, and vice versa, is of interest, and we will address this topic in the near future using our soft drink consumption data. We appreciate their assessment of our study design as “an ideal instrument to disentangle” these questions and look forward to meeting that challenge.
Association of Soft Drink Consumption with Increased Waist Circumference Should Be Adjusted for Body Mass Index Dear Editor:
1370
Author disclosures: P Traissac, J El Ati, A Gartner, Y Martin-Pre´vel, and F Delpeuch, no conflicts of interest.
Pierre Traissac Jalila El Ati Agne`s Gartner Yves Martin-Pre´vel Francis Delpeuch From the IRD (Institute of Research for Development), NUTRIPASS Research Unit (Population Nutrition in Southern Countries), Montpellier, France (PT, e-mail: [email protected], AG, YM-P, FD); and National Institute of Nutrition and Food Technology and Nutrition Surveillance and Epidemiology in Tunisia Research Laboratory, Tunis, Tunisia (JEA). ã 2015 American Society for Nutrition. J Nutr 2015;145:1370–2.
Downloaded from jn.nutrition.org at UNIV OF CALIFORNIA SAN DIEGO on June 5, 2015
We were very interested in the recent article by Funtikova et al. (1) entitled “Soft Drink Consumption Is Positively Associated with Increased Waist Circumference and 10-Year Incidence of Abdominal Obesity in Spanish Adults.” Their study, which was conducted in the city of Gerona, deals with a major public health issue and has a number of methodologic strengths including a prospective design with a high rate of follow-up, use of a validated FFQ for assessment of the main exposure, and careful control of confounding by other lifestyle factors, as well as the use of advanced statistical methods, including spline regression to assess associations, all highly commendable features. Nevertheless, we would like to point to a few issues regarding the choice of the main outcome in the analyses presented in the article. First, although the use of anthropometric proxies is standard in large-scale field studies, it is well documented that the use of waist circumference (WC) as a proxy for abdominal adiposity has its limits, and these should have been acknowledged more. One such limit is that WC does not distinguish between different types of abdominal fat accumulation, e.g., visceral vs. subcutaneous adipose tissues, which may be differently associated with adverse health outcomes (2, 3). This would be an interesting topic for discussion, especially when studying the specific association of soft drink consumption with central obesity (4). There are also technical difficulties involved in measuring WC in the field, especially among overweight or obese subjects, and these could also have been acknowledged (5). For example, the WHO recommends measuring WC in millimeters, rather than to the nearest 0.5 cm, as performed by Funtikova et al. (1). Although WC is a good predictor of cardiovascular disease risk, there also may be other reliable anthropometric proxies of abdominal adiposity and it would be interesting to assess whether the same associations are observed (6). Most importantly, it would be interesting to investigate if the associations observed by Funtikova et al. (1) are specific to abdominal adiposity (WC), or whether the same results would have been obtained using a proxy of overall adiposity such as BMI. Indeed, it is widely acknowledged that abdominal and overall adiposity in general and thus WC and, e.g., BMI, are extremely correlated. One consequence is that in many studies, similar associations with exposures are observed using either of these adiposity proxies. Unfortunately, the authors provide no data on the associations between the factors they studied and BMI either in the main text or in the extensive supplementary online material. Furthermore, as stated by the authors as one of the justifications for their study, it would seem that there is a current trend of increasing WC in all BMI categories and thus a growing discrepancy between the assessment of the burden of obesity using either abdominal or overall obesity (7–9). In addition, a number of authors consider that abdominal adiposity
is a better predictor of a variety of adverse health outcomes, including mortality risk (6), than a proxy of overall adiposity such as BMI. Thus, a major issue is being able to assess the factors involved in increased WC independently of increases in BMI. A number of studies deal with lifestyle correlates of WC (including the one we refer to here focused on association with soft drinks). But evidence of why people develop abdominal obesity independently of overall obesity is rare, although a few authors have put forward sedentary behavior, high energy intake, total and type of fat intake, alcohol intake, or lack of sleep as possible factors (10–12). Thus, a well-designed study such as that reported by the authors would seem to be an ideal instrument to disentangle the specific association of the exposure with increases in WC independently of increases in BMI from the association because of the strong correlation of WC with BMI. Adjusting WC for BMI is, indeed, not entirely straightforward statistically because of their strong correlation; however, there are a number of analytic modeling techniques [of which Funtikova et al. (1) are doubtless aware] available to achieve this goal, provided, of course, that height and weight data were available. Regarding height and weight, we assume they were measured because the Methods of the abstract does mention such measurements, but they are not listed in the anthropometrics paragraph of the article itself or referred to in the Results or Analyses, and there is only a very brief reference to the increase in prevalence of general obesity at the beginning of the Discussion. Thus, notwithstanding the merits of the results presented by Funtikova et al. (1), by adjusting the observed increase in WC associated with soft drink consumption for BMI, we believe the authors would have made an even more important contribution to the knowledge of why abdominal adiposity appears to be increasing more rapidly than BMI. This issue is indeed a major public health concern, especially in nutrition transition contexts where incidences of obesity are the highest and this discrepancy is especially worrisome.
References 1.
Author disclosures: H Schro¨der and A Funtikova, no conflicts of interest.
doi:10.3945/jn.115.211912.
Helmut Schro¨der Anna Funtikova
Reply to Traissac et al.
From the Cardiovascular Risk and Nutrition Research Group, Hospital del Mar Medical Research Institut (IMIM), Barcelona, Spain (HS, e-mail: [email protected], AF).
Dear Editor: We thank Traissac et al. for their interest in our recent report on the association between caloric beverage consumption, waist circumference (WC), and incidence of abdominal obesity (1) and appreciate the opportunity to respond to their comments. As Traissac et al. point out, abdominal adiposity measured by WC as a surrogate marker is a strong predictor for cardiometabolic health and mortality (2, 3). Furthermore, a recent study showed a greater utility of WC for identifying adults at cardiometabolic risk compared to BMI, fat mass, and percentage body fat (4). These findings, along with the high prevalence and marked increase of abdominal obesity in the population we
References 1.
2.
3.
Funtikova AN, Subirana I, Gomez SF, Fito´ M, Elosua R, Benı´tezArciniega AA, Schro¨der H. Soft drink consumption is positively associated with increased waist circumference and 10-year in cidence of abdominal obesity in Spanish adults. J Nutr 2015;145: 328–34. Zhang C, Rexrode KM, van Dam RM, Li TY, Hu FB. Abdominal obesity and the risk of all-cause, cardiovascular, and cancer mortality: sixteen years of follow-up in US women. Circulation 2008;117:1658–67. Fox KA, Despres JP, Richard AJ, Brette S, Deanfield JE. Does abdominal obesity have a similar impact on cardiovascular disease and diabetes? A study of 91,246 ambulant patients in 27 European countries. Eur Heart J 2009;30:3055–63.
Letters to the Editor
1371
Downloaded from jn.nutrition.org at UNIV OF CALIFORNIA SAN DIEGO on June 5, 2015
Funtikova AN, Subirana I, Gomez SF, Fito´ M, Elosua R, Benı´tezArciniega AA, Schro¨der H. Soft drink consumption is positively associated with increased waist circumference and 10-year incidence of abdominal obesity in Spanish adults. J Nutr 2015;145:328–34. 2. Demerath EW, Reed D, Rogers N, Sun SS, Lee M, Choh AC, Couch W, Czerwinski SA, Chumlea WC, Siervogel RM, et al. Visceral adiposity and its anatomical distribution as predictors of the metabolic syndrome and cardiometabolic risk factor levels. Am J Clin Nutr 2008;88: 1263–71. 3. Fox CS, Massaro JM, Hoffmann U, Pou KM, Maurovich-Horvat P, Liu CY, Vasan RS, Murabito JM, Meigs JB, Cupples LA, et al. Abdominal visceral and subcutaneous adipose tissue compartments: association with metabolic risk factors in the Framingham Heart Study. Circulation 2007; 116:39–48. 4. Maersk M, Belza A, Stodkilde-Jorgensen H, Ringgaard S, Chabanova E, Thomsen H, Pedersen SB, Astrup A, Richelsen B. Sucrosesweetened beverages increase fat storage in the liver, muscle, and visceral fat depot: a 6-mo randomized intervention study. Am J Clin Nutr 2012;95:283–9. 5. Mason C, Katzmarzyk PT. Variability in waist circumference measurements according to anatomic measurement site. Obesity (Silver Spring) 2009;17:1789–95. 6. Song X, Jousilahti P, Stehouwer CD, Soderberg S, Onat A, Laatikainen T, Yudkin JS, Dankner R, Morris R, Tuomilehto J, et al. Comparison of various surrogate obesity indicators as predictors of cardiovascular mortality in four European populations. Eur J Clin Nutr 2013;67:1298– 302. 7. Walls HL, Stevenson CE, Mannan HR, Abdullah A, Reid CM, McNeil JJ, Peeters A. Comparing trends in BMI and waist circumference. Obesity (Silver Spring) 2011;19:216–9. 8. Traissac P, Pradeilles R, El Ati J, Aounallah-Skhiri H, Eymard-Duvernay S, Gartner A, Be´ji C, Bougatef S, Martin-Prevel Y, Kolsteren P, et al. Abdominal vs. overall obesity among women in a nutrition transition context: geographic and socio-economic patterns of abdominal-only obesity in Tunisia. Popul Health Metr 2015;13:1. 9. Freedman DS, Ford ES. Are the recent secular increases in the waist circumference of adults independent of changes in BMI? Am J Clin Nutr 2015;101:425–31. 10. Chaput JP, Despre´s JP, Bouchard C, Tremblay A. Short sleep duration preferentially increases abdominal adiposity in adults: preliminary evidence. Clin Obes 2011;1:141–6. 11. Halkjaer J, Sorensen TI, Tjonneland A, Togo P, Holst C, Heitmann BL. Food and drinking patterns as predictors of 6-year BMI-adjusted changes in waist circumference. Br J Nutr 2004;92:735–48. 12. Wahlqvist ML, Hodgson JM, Ng FM, Hsu-Hage BH-H, Strauss BJ. The role of nutrition in abdominal obesity. Nutr Res 1999;19:85– 101.
studied (5), led to our decision to determine the impact of caloric beverage consumption on these outcomes, using WC as the indicator. Technical problems related to WC measurements in overweight or obese subjects certainly may occur but can be readily resolved if the personnel involved have received adequate training; we have found no reports showing a technical problem that results in a BMI category-specific bias. Generally, independent of the measurement protocol, WC measurement has shown excellent intra- and interobserver reliability (6, 7). We addressed this topic using several statistical models to ensure the consistency of our findings. In our opinion, the inclusion of other anthropometric measures as outcomes such as BMI, waist-to-height ratio, or WC adjusted for BMI (as the residuals of WC regressed on BMI) would have overloaded the manuscript. Therefore, although Traissac et al. are correct that we had access to additional measurements, we chose to focus on WC as a promising indicator that is often ignored in clinical practice. Although the present manuscript did not discuss any association between exposure and intra- or subcutaneous fat tissue, several other studies have shown that, of the 2 fat tissues, visceral adipose tissue has a stronger association, albeit in the same direction, with cardiovascular risk factors (8, 9). A recent intervention study in 47 overweight subjects used DXA and MRI to determine the effect of different beverages on fat distribution and other endpoints, finding a significant increase in visceral fat but not subcutaneous or total fat tissue after 6 mo of sucrose-sweetened soft drink consumption, compared to other beverages (10). Again, our study data were based on WC measurements; any discussion of the specific impact of soft drink consumption and different types of abdominal fat accumulation would have been speculative. We fully agree with Traissac et al. that the association of changes in abdominal adiposity independent of general adiposity, and vice versa, is of interest, and we will address this topic in the near future using our soft drink consumption data. We appreciate their assessment of our study design as “an ideal instrument to disentangle” these questions and look forward to meeting that challenge.
