Unsweetened Sparkling Water and Changes in Sweetness Perception in Adolescents
Condition: Obesity, Adolescent; PreDiabetes
MeSH terms: Pediatric Obesity
Study type: Interventional

Summary: 
      The study design is a prospective observational study in adolescents who are at risk for
      developing Type 2 Diabetes (T2D), to evaluate the effectiveness of sparkling water to reduce
      dietary intake of added sugars and thereby improve glycemia. Study data on consumption and
      the flavor profile of sparkling water will serve as a measure of acceptability. The study
      intervention will be to provide carbonated flavored sparkling water for 12 weeks to
      adolescents (and their families) who have a usual intake of 2 or more servings of sugar
      sweetened beverages (SSB) per day and are at a high risk for developing type 2 diabetes.
      Study measures will be obtained before and after the exposure to carbonated flavored
      sparkling water and each participant will serve as his/her own control. To encourage the
      participants to substitute the carbonated flavored sparkling water, study personnel will send
      them weekly iMessages through the Technology Assisted Dietary Assessment (TADA) app. In
      addition, investigators will monitor the participants' diet, using the TADA app, every two
      weeks, for 4 days. Study measurements will be obtained at baseline, before the intervention,
      during and at the end of the 12 week intervention.

      Objective: Determine the effect of reducing added sugars intake by substituting carbonated
      sparkling water on T2D risk in adolescents.

      Hypothesis: Adolescents who decrease consumption of SSB by substituting sparkling water will
      experience decreased blood glucose concentrations and increased insulin sensitivity during an
      oral glucose tolerance test and decreased glucose excursions during continued glucose
      monitoring, compared to those who do not decrease consumption of SSB.
    

Detailed description: 
      Importance of studying added sugars in adolescents. Research that leads to nutritional
      strategies to prevent T2D in adolescents is an urgent pursuit. One particular contributing
      factor to the growth of T2D and prediabetes in adolescents is the increased consumption of
      added sugars. Adolescents in the U.S. have high intakes of added sugars which could have poor
      health implications. Added sugars are found in sugar sweetened beverages and desserts and
      snacks, top sources of energy for adolescents, and calories from added sugars contribute to
      16% of the total energy intake. Levels are well above recommendations from leading scientific
      organizations, which suggest limiting added sugars to less than 10% of energy. However, it is
      not clear whether sugar reduction to less than 10% of energy is palatable for an adolescent
      population that prefers sweetened foods and beverages. Moreover, uncertainty about the
      evidence linking added sugar consumption to risk of disease has made policies that seek to
      reduce dietary intake of added sugar controversial. The controversy impairs large-scale
      implementation of recommendations to reduce intake of added sugars by individuals,
      clinicians, policy makers and industry stakeholders.

      Evidence linking added sugars and risk of type 2 diabetes and cardiovascular disease lacks
      information on adolescents. Many epidemiological studies in adults, but not all show the
      concept that after controlling for energy intake, high consumption of sugar-sweetened foods
      is a risk factor for T2D. Epidemiological studies also associate high consumption of added
      sugars, particularly from sugar sweetened beverages (SSB), with increased adiposity
      (including central adiposity) and dyslipidemia. These studies formed the basis of
      recommendations to limit added sugar consumption from the American Heart Organization. The
      data in youth is limited. Two small randomized studies compared the effects of glucose versus
      fructose beverages on insulin sensitivity in adolescents and findings were mixed. One
      longitudinal cohort study showed that higher consumption of added sugars, from SSB, was
      associated with hyperglycemia and impaired insulin sensitivity in youth aged 8 - 12 years.
      One study showed that high amounts of added sugars may induce insulin resistance and
      beta-cell dysfunction and such effects can occur independent of adiposity. The literature
      lacks evidence linking high consumption of added sugars to risk of developing youth-onset
      T2D.

      Substituting Flavored Sparkling Water for Sugar Sweetened Beverages. Instead of sugar, food
      manufacturers typically sweeten foods beverages using low-calorie or artificial sweeteners.
      "Diet" versions of SSB have been available for several decades and are widely used by adults
      and children. However the safety of low calorie sweeteners is controversial and many in the
      scientific and lay communities do not promote their use as a substitute for SSB. We propose
      that an alternative to SSB may be found in sparkling waters (carbonated water with flavoring,
      completely unsweetened), which are commercially available in soda-like flavors like cola or
      Dr. Pepper™. The rationale for the current project is the urgent need for an effective
      strategy to combat adolescent T2D which investigators will address by demonstrating the
      benefit of an intervention to reduce added sugars. The objective of the study is to
      demonstrate whether substituting sparkling water for SSB has benefits for in vivo
      physiological measures of glycemia while maintaining flavor acceptability to adolescents who
      are at risk for diabetes.
    

Intervention name(s): Unsweetened flavored sparkling water
Intervention type(s): Other
Intervention description(s): Unsweetened sparkling waters are carbonated water with flavoring, completely unsweetened, which are commercially available in soda-like flavors like cola
Intervention model: Single Group Assignment
Intervention model description: Prospective, before and after, cohort study
Masking: None (Open Label)
Primary purpose: Basic Science