NNNS: Estimated and Acceptable Intake (2011)

Citation:
 
Study Design:
Class:
- Click here for explanation of classification scheme.
Quality Rating:
Research Purpose:

To assess Italian teenagers' intake of saccharin, aspartame, acesulfame K and cyclamate and their associated food sources. The study also estimated this population's probability of exceeding the Acceptable Daily Intake (ADI) levels.

Inclusion Criteria:

Students aged 13 to 19 years, from 11 classes (second, third and fourth year) at a secondary school in Rome, Italy.

Exclusion Criteria:
  • Subjects who did not complete their food records
  • Subjects whose food records were determined to be unreliable.
Description of Study Protocol:

Recruitment

  • Eleven classes of students from a secondary school were selected to participate
  • Although the convenience sample was not a random sample of teenagers, the characteristics of the school chosen were such that subjects were fairly typical Roman teens
  • The specific purpose of the study was not disclosed to the students or their teachers: They were told that the study was to examine the typical eating patterns of teenagers
  • As an incentive, students were informed that at the end of the study they would receive a detailed analysis of their own diet and specific nutritional advice.

Design

  • Students were asked to maintain a 14-consecutive day food record
  • Subjects were asked to keep food package labels so that the field workers could check for weight, volume and presence of artificial sweeteners
  • Subjects were instructed on how to express food and beverage quantities with standard household measures. Photos were also used to help them understand portion sizes.
  • The food diaries were collected three times each week and at this time interviewers reviewed the food diary with each individual subject and checked food descriptions, brands, recipe ingredients and quantities. Queries were made to identify omissions.
  • Manufacturers provided the sweetener content of sugar-free products (soft drinks, candies, chewing gums, yogurts, jam and table-top sweeteners).

Statistical Analysis

  • All analyses were carried out using SPSS
  • High intakes were assessed as the 95th percentile of intake among consumers. For statistical reliablity, this N must be at least 140 subjects: If the number was fewer, then only the maximum intake was reported.
Data Collection Summary:

Timing of Measurements

  • Fourteen-consecutive day food diary.

Dependent Variables

  • Saccharin, aspartame, acesulfame K and cyclamate intakes were determined from analysis of 14-day food diaries and expressed in mg per kg of body weight of each respondent.

Independent Variables

  • Dietary intake: Measured using a 14-day food diary. Each food or beverage was codified with the quantity, unit of measurement and food code.
  • Validation routines were applied to ensure completeness and accuracy compared to the diary.
Description of Actual Data Sample:
  • Initial N: 241 students
  • Attrition (final N): Final N=212 (56 male, 156 female); 29 were excluded for the following reasons: One was absent from school, seven did not provide anthropometric data, six did not complete the 14-day food diary, 15 were determined by interviewers to be unreliable in reporting intakes
  • Age: 13 to 19 years old
  • Ethnicity: Italian.

Other Relevant Demographics

  • Healthy
  • Medium social class.

Anthropometrics

  • Weight, height, body mass index
    • Three subjects (one male and two female) were classified as "underweight"
    • Twenty-nine subjects (11 male and 18 female) were classified as "overweight."
  • Basal metabolic rate (BMR): Estimated from weight and height using Schofield equations. Individual BMR ratios were calculated by dividing energy intake by BMR.
  • Triceps and subscapular skinfold measurements, using standardized procedures (Lohman et al, 1988).
Location
  • Rome, Italy from September to December 1996.
Summary of Results:
  • Mean basal metabolic ratio in non-dieting subjects (N=197) was 1.61 for males and 1.50 for females; in dieting subjects (N=15 females), the BMR was 1.2
  • Sugar-free products were consumed by 77% of the subjects, however in male consumers the consumption was occasional (mean of only 2.4 eating occasions in 14 days). Female consumers reported 7.5 eating occasions and females who were dieting reported 13.1.
  • Mean daily intake among consumers was 0.24mg per kg of body weight for cyclamate (13 subjects), 0.21mg per kg of body weight for saccharin (nine subjects), 0.03mg per kg of body weight for aspartame (162 subjects) and 0.02mg per kg of body weight for acesulfame K (56 subjects)
  • None of the subjects exceeded the ADI (Acceptable Daily Intake) of for any of the intense sweeteners.
Author Conclusion:
  • The study projections were based on the present levels of use of intense sweeteners in sugar-free products and on the dietary pattern observed in the study population. Results suggest that consumption levels could approach the allowed Acceptable Daily Intake only if subjects with high intakes of both soft drinks and table-top sugar substituted these items with sugar-free beverages and table-top sweeteners containing either saccharin or cyclamate.
  • Since this study was conducted during the colder seasons of the year (fall and winter), results may have slightly underestimated the intake of beverages and therefore of intense sweeteners from diet soft drinks.
Funding Source:
University/Hospital: Universidade Estadual de Campinas
Reviewer Comments:

The Non-Nutritive Sweeteners Expert Working Group limited its conclusions to sweeteners that are currently available in the United States. Cyclamates are not sold in the US. Therefore, although this article and associated worksheet include data about cyclamates, it will not be included in the working group's evidence-based conclusions.

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) Yes
  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) Yes
 
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? Yes
  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? Yes
  2.3. Were health, demographics, and other characteristics of subjects described? Yes
  2.4. Were the subjects/patients a representative sample of the relevant population? No
3. Were study groups comparable? Yes
  3.1. Was the method of assigning subjects/patients to groups described and unbiased? (Method of randomization identified if RCT) Yes
  3.2. Were distribution of disease status, prognostic factors, and other factors (e.g., demographics) similar across study groups at baseline? Yes
  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? Yes
  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? Yes
  4.1. Were follow-up methods described and the same for all groups? Yes
  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%.) Yes
  4.3. Were all enrolled subjects/patients (in the original sample) accounted for? Yes
  4.4. Were reasons for withdrawals similar across groups? Yes
  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? No
  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.) No
  5.3. In cohort study or cross-sectional study, were measurements of outcomes and risk factors blinded? No
  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? Yes
  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? Yes
  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? Yes
  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? Yes
  10.2. Was the study free from apparent conflict of interest? Yes