Effect of Fructose-containing Sugar Sweetened Beverages (SSBs) on Body Weight: A Systematic Review and Meta-analysis of Controlled Feeding Trials to Provide Evidence-based Guidance for Nutrition Guidelines Development
Trial Snapshot
- Phase
- Not Applicable
- Sponsor
- Enrollment
- 1
- Locations
- 1
- Primary Endpoint
- Body weight
Study Overview
Brief Summary
Since uncontrolled observational studies first linked fructose to the epidemic of obesity almost a decade ago, it has become a focus of intense concern regarding its role in the obesity epidemic. Despite the uncertainties in the evidence,the recommendations of international health organizations have cautioned against moderate to high intakes fructose-containing sugars, especially those from sugar sweetened beverages (SSBs). To improve the evidence on which nutrition recommendations are based, the investigators propose to study of the effect of fructose-containing sugar sweetened beverages (SSBs)on body weight, by undertaking a systematic synthesis of the data taken from all available clinical studies in humans. This technique has the strength of allowing all of the available data to be pooled together and differences to be explored in groups of different study participants (healthy humans of different sex, weight, and age and in those with diseases which predispose to disturbances in metabolism, such as diabetes) with dietary fructose in different forms, doses, and with differing durations of exposure. The findings generated by this proposed knowledge synthesis will help improve the health of consumers through informing recommendations for the general public, as well as those at risk of diabetes and cardiovascular disease.
Detailed Description
Background: Fructose has become a focus of intense concern regarding its links to the obesity epidemic. There have been dozens of editorials, commentaries, and letters in the scientific literature and numerous pieces in the lay and social media calling for efforts to restrict its intake and even regulate it like tobacco or alcohol. Uncontrolled observational studies which have linked increasing fructose intake with increasing obesity rates since the 1970s and animal models of fructose overfeeding at levels of exposure far beyond actual population levels of intake have been used to underpin this debate. Evidence from observational studies and controlled feeding trials also suggest a positive association between the consumption of fructose-containing sugar-sweetened beverages, in which high fructose corn syrup (HFCS) is the main sweetener, and increased energy consumption and weight gain, but not all meta-analyses have supported this conclusion. Despite the limitations in extrapolating from these data and their inconsistency with data from controlled trials in humans (the highest level of evidence used in evidence based medicine), the American Heart Association (AHA) have taken a risk reduction approach to added fructose-containing sugars, especially those from sugar sweetened beverages (SSBs), setting highly restrictive upper thresholds for their intake to achieve and maintain healthy body-weights.
Objective: To improve the evidence on which recommendations and public health policy are based, we propose to conduct a systematic review and meta-analysis of the effect of fructose-containing SSBs on body weight in controlled feeding trials.
Design: The planning and conduct of the proposed meta-analyses will follow the Cochrane handbook for systematic reviews of interventions. The reporting will follow the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines.
Data sources. MEDLINE, EMBASE, CINAHL and The Cochrane Central Register of Controlled Trials (Clinical Trials; CENTRAL) will be searched using appropriate search terms, supplemented by manual, hand searches of bibliographies.
Study selection: We will include controlled feeding trials investigating the effect of fructose-containing (fructose, sucrose, and HFCS) SSBs in isocaloric exchange for other carbohydrate sources (isocaloric trials) or hypercaloric exchange for beverages containing a non-nutritive sweetener or added to a control diet as a source of excess energy (hypercaloric trials) on body weight in humans. Studies that are <7-days diet duration, lack a control, or do not provide viable endpoint data will be excluded.
Study Design
- Study Type
- Observational
- Time Perspective
- Prospective
Eligibility Criteria
- Sex
- All
- Accepts Healthy Volunteers
- No
Inclusion Criteria
- •Trials in humans
- •Oral fructose intervention
- •Suitable control (i.e. another carbohydrate source in isocaloric exchange for fructose or a control diet which is compared with the same diet supplemented with excess energy from fructose)
- •>= 7-days diet duration
- •Viable endpoint data
Exclusion Criteria
- •Non-human studies
- •IV or parenteral fructose
- •High fructose corn syrup or sucrose intervention (except where these are the comparators)
- •Lack of a suitable control
- •< 7-days diet duration.
- •No viable endpoint data
Outcomes
Primary Outcomes
Body weight
Time Frame: 1.5-years
Secondary Outcomes
No secondary outcomes reported
Investigators
John Sievenpiper
Adjunct Research Fellow
University of Toronto