Results of Study on Diet Sodas and Older Adults Should be Treated with Caution Due to Study Limitations

ATLANTA (March 17, 2015) — The recent study “Diet Soda Intake Is Associated with Long-Term Increases in Waist Circumference in a Biethnic Cohort of Older Adults: The San Antonio Longitudinal Study of Aging (SALSA)” (1) suffers from several limitations, which likely confound the study’s conclusions.

  • The authors note that the waist circumference (abdominal fat) findings were not significant.
  • As men and women age they lose muscle mass, and typically there is an increase in abdominal fat (which is measured by waist circumference). (2)
  • This study cannot show cause and effect, but instead only indicates a possible association.
  • The study was not designed to evaluate the relationship between diet soda consumers and non-consumers in all subgroups, limiting the conclusions that can be made.
  • Without information regarding dietary or calorie intake, the implications of these results are limited.
In the study of Mexican-American and European-American individuals aged 65 and older, “a significant amount of important data was missing including diet records, family history, cultural differences and lifestyle, which are critical when studying Hispanics who usually continue to eat large portions yet become more sedentary as they become older,” said Sylvia Meléndez Klinger, MS, RDN, LDN, CPT and scientific advisor to the Calorie Control Council.
The use of low-calorie sweeteners (LCSs) in weight management has been shown to be beneficial. Dr. James O. Hill, a recognized obesity expert, said in the American Journal of Clinical Nutrition (AJCN), 2014, “In randomized controlled trials (RCTs), the use of LCSs is associated with lower body weight, BMI, and waist circumference. In prospective cohort studies, the use of LCSs is associated with less weight gain but a slightly greater BMI. Clear evidence that the use of LCSs helps—not hurts—in weight management.”
Previous research has shown that individuals consuming diet products have a healthier lifestyle and that many individuals consume diet products as an effective way to reduce calorie intake (3, 4).  Diet soda consumers in this study also tended to have increased physical activity as estimated by leisure-time energy expenditure.  While approaches to treat obesity in older individuals is controversial, diet modifications can be a successful part of a weight management program for older adults. (5, 6)
  1. S.P.G. Fowler, K Williams, and H.P. Hazuda.  Diet Soda Intake Is Associated with Long-Term Increases in Waist Circumference in a Biethnic Cohort of Older Adults: The San Antonio Longitudinal Study of Aging.  J Am Geriatr Soc 2015. DOI: 10.1111/jgs.13376.
  2. Janssen I, Heymsfield SB, Wang ZM, Ross R. Skeletal muscle mass and distribution in 468 men and women aged 18-88 yr. J Appl Physiol (1985). 2000 Jul;89(1):81-8.
  3. Drewnowski, A.; Rehm, C.D.   Consumption of Low-Calorie Sweeteners among U.S. Adults Is Associated with Higher Healthy Eating Index (HEI 2005) Scores and More Physical Activity. Nutrients 2014, 6, 4389-4403.
  4. Peters JC, Wyatt HR, Foster GD, Pan Z, Wojtanowski AC, Vander Veur SS, Herring SJ, Brill C, Hill JO. The effects of water and non-nutritive sweetened beverages on weight loss during a 12-week weight loss treatment program. Obesity (Silver Spring). 2014 Jun;22(6):1415-21. doi: 10.1002/oby.20737.
  5. Waters DL, Ward AL, Villareal DT. Weight loss in obese adults 65 years and older: a review of the controversy. Exp Gerontol. 2013 Oct;48(10):1054-61. doi: 10.1016/j.exger.2013.02.005.
  6. Mathus-Vliegen EM; Obesity Management Task Force of the European Association for the Study of Obesity. Prevalence, pathophysiology, health consequences and treatment options of obesity in the elderly: a guideline. Obes Facts. 2012;5(3):460-83. doi: 10.1159/000341193.
faq2Do you have questions about low-calorie sweeteners? Want to learn more about maintaining a healthy lifestyle? You asked and we listened. Our resident Registered Dietitians answered the most popular questions about low-calorie sweeteners.

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