Nutritive and Non-Nutritive Sweeteners

NNNS: High Fructose Corn Syrup (HFCS) (2010)

Citation:

Duffey KJ, Popkin BM. High-fructose corn syrup: Is this what's for dinner? Am J Clin Nutr. 2008; 88(suppl): 1,722S-1.732S.

PubMed ID: 19064537

Study Design:

Descriptive Study

Class:

C - Click here for explanation of classification scheme.

Quality Rating:

NEUTRAL: See Quality Criteria Checklist below.

Research Purpose:

The authors' purpose was to determine and describe long-term trends in US consumption of added sugars and HFCS, including intake and availability from foods and beverages.

Inclusion Criteria:

Data were used from the following instruments:

Nationwide Food Consumption Surveys (1965 and 1977)
Continuing Survey of Food Intake by Individuals (1989 to 1991)
National Health and Nutrition Examination Surveys (1999 to 2000, 2001 to 2002, 2003 to 2004)
USDA Economic Research Service Food Availability databases.

Exclusion Criteria:

Not applicable.

Description of Study Protocol:

Design

The USDA Economic Research Service Food Availability databases were used to estimate total HFCS availability in pounds per person per day
- The proportion of HCFS-55 vs. HCFS-42 was calculated
- All soda and fruit beverages were assumed to contain 100% HFCS
USDA Food Composition Tables were used to estimate the HFCS content of foods and beverages:
- Two different estimation methods were applied to all foods and beverages:
  - NDS method: The University of Minnesota's Nutrition Coordinating Center [NCC] Nutrient Database System [NDS] sugars data was used along with data from the USDA Food Composition Tables
    - The NDS also contains information from manufacturers and the scientific literature
    - A three-step process was used to estimate HFCS:
      - The proportion of added sugar that was fructose was calculated by dividing fructose (grams per 100g food) by added sugars (grams per 100g food) for each individual food (988 food codes total)
      - The proportion of added sugar that was HFCS was calculated by multiplying the proportion of fructose by the total amount of added sugars, resulting in a gram amount of HFCS for each food code
      - HFCS consumption was calculated for each food, summed across food groups, and presented by food group across time
  - Glinsmann method:
    - The FDA produced estimates of added sugars in foods in 1986
    - Using FDA estimated, Glinsmann et al estimated the proportion of sugars including HFCS in food categories
    - For each food category, a factor was created for HFCS, which was multiplied by total added sugars to estimate total HFCS for that food category
- Although results from both methods are presented by the investigators, the Glinsmann method was preferred:
  - Glinsmann's results had been used successfully in at least one other HFCS study
  - NCC data were not intended to be used with USDA survey data, and used a different set of food identifiers
  - NCC foods were divided differently from USDA foods
- Accurate information regarding time and use of HFCS in the US food supply were available only from 1999 to 2004
- For the sake of consistency, the investigators modified and recategorized some food groups and foods during their analysis.

Statistical Analysis

SAS (v.9.1.3; SAS Institute Inc, Cary, NC) and Stata (v.9.2; Stata Corp LP, College Station, TX) were used
Level of statistical significance: 0.01
Results for all ages are combined since trends for Americans aged two to 18 years did not differ from Americans aged 19 or more years.

Data Collection Summary:

Timing of Measurements

Not applicable.

Description of Actual Data Sample:

Other relevant demographics: American study
Location: Department of Nutrition, North Carolina University, Chapel Hill, North Carolina.

Summary of Results:

Key Findings

When initially introduced during the 1970s, HFCS represented less than 1% of caloric sweeteners in the US; by 2004 it represented 42% of all caloric sweeteners used
HFCS-55 comprised 59.5% of HFCS use in 2004, compared to the introduction of HFCS when HFCS-42 was the only variety available
Although HFCS represents about 40% of total sweetener use in the US, it is important to remember that the proportion of HFCS is much higher in some food groups
Since 1970, total fructose intake has increased 18% (45.7 to 53.7g per day) while HFCS intake has increased from 0.5g per day to 52.4g per day
Total intake of fructose and HFCS may have slightly declined since 2000 (NS)
From 1989 to 2004 total calories consumed as HFCS increased from 77kcals per person per day to 189kcals per person per day
In 2004, HFCS provided 8.3% total kcals per person and 15.7% total carbohydrates per person
In 2004, fruit drinks and soft drinks provided the greatest number of calories from HFCS, accounting for 40kcal per person per day for fruit drinks and 158kcals per person per day for soft drinks. In 1989, these beverages provided 18kcals per person per day for fruit drinks and 82kcals per person per day for soft drinks
Other drinks, including sweetened tea and sports drinks, provided additional HFCS calories and showed similarly increased consumption over the same time period
HFCS in foods does not appear to provide significant calories per person as do sweetened beverages, but overall added sugars have increased
When stratified by sugar consumption, the highest quintile of intake from added sugars increased from 640kcals from added sugars per day in 1965 to 840kcals from added sugars per day in 2004
For beverages, the lowest quintile consumed 0% added sugars, and although quintiles two and three increased added sugar consumption over the time period, the upper two quintiles (fourth and fifth) appeared to drive the trends; results were similar for foods
HFCS calories increased 100% to 505kcals HFCS per day for the top 20% of the population between 1989 and 2004, and this trend toward increased consumption was driven by the top two quintiles
Beverages provided 450kcals HFCS in 2004 for the top quintile.

Author Conclusion:

The availability and consumption of HFCS has increased over the past 30 years
Because many foods that contain HFCS are consumed as snacks rather than meals, HFCS isn't necessarily what's for dinner; it's what's in addition to dinner.

Funding Source:

Other:

Unknown -- authors reported no conflicts of interest

Reviewer Comments:

The authors noted several study limitations:

Data regarding HFCS had to be estimated
Direct measures of fructose were not available for all foods calculated
Data were limited by different collection methods and different time frames for the data collected over several decades.

Quality Criteria Checklist: Primary Research
Relevance Questions
	1.	Would implementing the studied intervention or procedure (if found successful) result in improved outcomes for the patients/clients/population group? (Not Applicable for some epidemiological studies)	N/A
	2.	Did the authors study an outcome (dependent variable) or topic that the patients/clients/population group would care about?	Yes
	3.	Is the focus of the intervention or procedure (independent variable) or topic of study a common issue of concern to dieteticspractice?	Yes
	4.	Is the intervention or procedure feasible? (NA for some epidemiological studies)	N/A

Validity Questions
1.	Was the research question clearly stated?		Yes
	1.1.	Was (were) the specific intervention(s) or procedure(s) [independent variable(s)] identified?	N/A
	1.2.	Was (were) the outcome(s) [dependent variable(s)] clearly indicated?	Yes
	1.3.	Were the target population and setting specified?	Yes
2.	Was the selection of study subjects/patients free from bias?		N/A
	2.1.	Were inclusion/exclusion criteria specified (e.g., risk, point in disease progression, diagnostic or prognosis criteria), and with sufficient detail and without omitting criteria critical to the study?	Yes
	2.2.	Were criteria applied equally to all study groups?	N/A
	2.3.	Were health, demographics, and other characteristics of subjects described?	N/A
	2.4.	Were the subjects/patients a representative sample of the relevant population?	N/A
3.	Were study groups comparable?		???
	3.1.	Was the method of assigning subjects/patients to groups described and unbiased? (Method of randomization identified if RCT)	N/A
	3.2.	Were distribution of disease status, prognostic factors, and other factors (e.g., demographics) similar across study groups at baseline?	N/A
	3.3.	Were concurrent controls or comparisons used? (Concurrent preferred over historical control or comparison groups.)	N/A
	3.4.	If cohort study or cross-sectional study, were groups comparable on important confounding factors and/or were preexisting differences accounted for by using appropriate adjustments in statistical analysis?	N/A
	3.5.	If case control study, were potential confounding factors comparable for cases and controls? (If case series or trial with subjects serving as own control, this criterion is not applicable.)	N/A
	3.6.	If diagnostic test, was there an independent blind comparison with an appropriate reference standard (e.g., "gold standard")?	N/A
4.	Was method of handling withdrawals described?		N/A
	4.1.	Were follow-up methods described and the same for all groups?	N/A
	4.2.	Was the number, characteristics of withdrawals (i.e., dropouts, lost to follow up, attrition rate) and/or response rate (cross-sectional studies) described for each group? (Follow up goal for a strong study is 80%.)	N/A
	4.3.	Were all enrolled subjects/patients (in the original sample) accounted for?	N/A
	4.4.	Were reasons for withdrawals similar across groups?	N/A
	4.5.	If diagnostic test, was decision to perform reference test not dependent on results of test under study?	N/A
5.	Was blinding used to prevent introduction of bias?		N/A
	5.1.	In intervention study, were subjects, clinicians/practitioners, and investigators blinded to treatment group, as appropriate?	N/A
	5.2.	Were data collectors blinded for outcomes assessment? (If outcome is measured using an objective test, such as a lab value, this criterion is assumed to be met.)	N/A
	5.3.	In cohort study or cross-sectional study, were measurements of outcomes and risk factors blinded?	N/A
	5.4.	In case control study, was case definition explicit and case ascertainment not influenced by exposure status?	N/A
	5.5.	In diagnostic study, were test results blinded to patient history and other test results?	N/A
6.	Were intervention/therapeutic regimens/exposure factor or procedure and any comparison(s) described in detail? Were interveningfactors described?		Yes
	6.1.	In RCT or other intervention trial, were protocols described for all regimens studied?	N/A
	6.2.	In observational study, were interventions, study settings, and clinicians/provider described?	N/A
	6.3.	Was the intensity and duration of the intervention or exposure factor sufficient to produce a meaningful effect?	Yes
	6.4.	Was the amount of exposure and, if relevant, subject/patient compliance measured?	Yes
	6.5.	Were co-interventions (e.g., ancillary treatments, other therapies) described?	N/A
	6.6.	Were extra or unplanned treatments described?	N/A
	6.7.	Was the information for 6.4, 6.5, and 6.6 assessed the same way for all groups?	N/A
	6.8.	In diagnostic study, were details of test administration and replication sufficient?	N/A
7.	Were outcomes clearly defined and the measurements valid and reliable?		Yes
	7.1.	Were primary and secondary endpoints described and relevant to the question?	Yes
	7.2.	Were nutrition measures appropriate to question and outcomes of concern?	Yes
	7.3.	Was the period of follow-up long enough for important outcome(s) to occur?	Yes
	7.4.	Were the observations and measurements based on standard, valid, and reliable data collection instruments/tests/procedures?	Yes
	7.5.	Was the measurement of effect at an appropriate level of precision?	Yes
	7.6.	Were other factors accounted for (measured) that could affect outcomes?	Yes
	7.7.	Were the measurements conducted consistently across groups?	Yes
8.	Was the statistical analysis appropriate for the study design and type of outcome indicators?		Yes
	8.1.	Were statistical analyses adequately described and the results reported appropriately?	Yes
	8.2.	Were correct statistical tests used and assumptions of test not violated?	Yes
	8.3.	Were statistics reported with levels of significance and/or confidence intervals?	Yes
	8.4.	Was "intent to treat" analysis of outcomes done (and as appropriate, was there an analysis of outcomes for those maximally exposed or a dose-response analysis)?	N/A
	8.5.	Were adequate adjustments made for effects of confounding factors that might have affected the outcomes (e.g., multivariate analyses)?	Yes
	8.6.	Was clinical significance as well as statistical significance reported?	N/A
	8.7.	If negative findings, was a power calculation reported to address type 2 error?	N/A
9.	Are conclusions supported by results with biases and limitations taken into consideration?		Yes
	9.1.	Is there a discussion of findings?	Yes
	9.2.	Are biases and study limitations identified and discussed?	Yes
10.	Is bias due to study's funding or sponsorship unlikely?		Yes
	10.1.	Were sources of funding and investigators' affiliations described?	N/A
	10.2.	Was the study free from apparent conflict of interest?	Yes