20120412 - Nutrition claims and balance of breakfast cereals - 2012

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# Nutrition claims and balance of breakfast cereals

Nutrition and health claims are commonly used when marketing breakfast cereals. As claims cannot be legally made unless products meet such claims, it is of little interest testing the truth of individual claims. However, it is of interest to test whether individual claims inform about overall nutritional balance (BNI). This way, a consumer may rely on any significant claim for choosing more balanced breakfast cereals. This article summarizes research done in this regards (for more detail see Perezgonzalez, 2012b3).

Illustration 1 collates statistical information for seven claims: group medians for cereals with and without a particular claim, tests for equality of independent rank distributions (Mann-Whitney U, used to assess group differences), correlations of each claim with the BNI (Spearman's rho), and regression coefficients of each claim on the BNI4.

Illustration 1: Medians, Mann-Whitney U tests, and correlation and regression coefficients per group
Claims Md 'no' Md 'yes' U rho β R
Wholegrain 55.58 34.27 416.0** -.323** -.318** .482**
Low fat 35.40 44.65 405.0* .256* .272** Adj.R
Low sugar 39.68 22.04 61.5* -.224* -.270** .449
High fiber 56.21 36.81 608.5 -.190 ---
Low sodium 40.89 33.14 337.5 -.171 ---
Pick Me sun 39.59 29.53 62.5 -.150 ---
Heart health 36.99 40.89 609.0 .043 ---
(Dependent variable = BNI. Medians closer to 0.0 indicate greater balance. * p ≤ .05; ** p ≤ .01. Sig ≤ .05, 2-tailed)

According to above results, it can be concluded that:

• Cereals with a 'wholegrain' claim have a BNI distribution significantly lower (median = 34.27; U = 416, p ≤ .01) than products without such claim (median = 55.58). Such claim alone could help identify some 32% of more nutritionally balanced products (rho).
• Cereals with a 'low fat' claim have a BNI distribution significantly higher (median = 44.65; U = 405, p ≤ .05) than products without such claim (median = 35.40). The absence of such claim alone could help identify some 26% of more nutritionally balanced products.
• Cereals with a 'low sugar' claim have a BNI distribution significantly lower (median = 22.04; U = 61.5, p ≤ .05) than products without such claim (median = 39.68). Such claim alone could help identify some 22% of more nutritionally balanced products.
• The combined appearance of above three claims on the same product could help identify some 49% of more nutritionally balanced products in the sample (R), and may help identify about 45% of more nutritionally balanced products in the population (adj.R).
• The remaining claims have BNI distributions not significantly different between groups. They are, thus, less dependable for identifying nutritional balance.

# Methods

### Research approach

Exploratory study.

### Sample

A stratified sample of 79 breakfast cereals (ie, oats, wheat, rice, corn, bran and muesli), collected in a convenient manner (see Perezgonzalez, 2012a2).

### Materials

The main (or dependent) variable was the balanced nutrition classification as assessed using the Balanced Nutrition Index™ (BNI™) technology (see Perezgonzalez, 20111).

Grouping (or independent) variables were seven nutrition-related or health-related marketing claims: high fiber, low sodium, low sugar, low fat, wholegrain, heart health, and Pams' "Pick Me sun" logo. A claim was considered valid for research independently of whether the claim was a broad statement (eg, low fat) or a specific one (eg, 98% fat free).

### Analysis

• The distribution of the BNI variable was significantly non-normal, some groups were too small in size and not all variables related linearly with the dependent variable. Therefore, a non-parametric approach was used for data analysis4.
• Main analyses: tests of significance (Fisher's approach) based on sig ≤ .05 or more extreme probabilities, 2-tailed.
• Main tests: Mann-Whitney U test for equality of ranked distributions of independent groups, Spearman's rho correlations, and multiple correlation on ranked data.
• All analyses were carried out with SPSS-v18 (PASW Statistics 18).

### Generalization potential

Most breakfast products were produced locally or imported and exported from or to Australia, respectively. Thus, the results of this study may be generalizable to the following populations (in order of decreasing generalization power):

• Australia.
• Internationally, if one assumes breakfast products to be of approximately similar nutritional composition anywhere.
References
1. PEREZGONZALEZ Jose D (2011). Balanced Nutrition Index™ (BNI™). Journal of Knowledge Advancement & Integration (ISSN 1177-4576), 2011, pages 20-21. Also retrievable from Wiki of Science.
2. PEREZGONZALEZ Jose D (2012a). Breakfast cereals. The Balanced Nutrition Index (ISSN 1177-8849), 2012, issue 3. (Retrievable from The Balanced Nutrition Index journal.)
3. PEREZGONZALEZ Jose D (2012b). Marketing claims and the nutritional balance of breakfast cereals. Journal of Knowledge Advancement & Integration (ISSN 1177-4576), 2012, pages 97-104. Also retrievable from Wiki of Science.
+++ Footnotes +++
4. Regression analyses were carried out on ranked data.

# Want to know more?

BNI™ journal (2012, issue 3) - Breakfast cereals
This issue of the Balanced Nutrition Index™ journal collates all BNI™ nutrition information for the original sample in a single book. You can also access information about each individual breakfast cereal on the BNI™ database and aggregated information on Wiki of Science (nutritional balance of food)
Wiki of Science - Marketing claims and the nutritional balance of breakfast cereals