|[Data]||[<Normal page] [PEREZGONZALEZ Jose D (2011). Nutrition claims and the BNI of yogurts. Journal of Knowledge Advancement & Integration (ISSN 1177-4576), 2012, pages 228-230.]|
Nutrition claims and the BNI of yogurts
Nutrition claims are commonly used when marketing yogurts. As many of these claims cannot be legally made unless products meet such claims, it is of little interest to test the truth of individual claims. However, it is of interest to test whether such claims inform about overall nutritional balance (BNI). This way, a consumer may rely on any significant claim for choosing more balanced products. This article summarizes research done in this regards (for an in-depth description see Perezgonzalez, 2011c3).
Illustration 1 collates relevant statistical information about three nutritional claims appearing on yogurts: low sugar, low fat and high fiber4. The results seem to support several main inferences. Firstly, regarding yogurts with 'high fiber' claims, that yogurts with such claims have an average BNI lower (median = 76.93) than other yogurts (median = 90.50), that such difference is also found between groups (U = 480, p < 0.01) and that the corresponding correlation indicates a trend between sporting a fiber claim and lower nutritional unbalance (rho = -0.225, p < 0.01). Secondly, regarding yogurts with 'low fat' claims, that yogurts with such claims have an average BNI lower (median = 89.62) than other yogurts (median = 96.76), and group differences and correlation are also statistically significant. And thirdly, that yogurts with 'low sugar' claims also have a BNI lower than other yogurts, although this inference may seem contradictory given that the median of yogurts with 'low sugar' claims (= 92.19) is higher than that of other yogurts (= 90.50) (which is due to a discrepancy when reporting results5, see Perezgonzalez, 2011c3 for more information in this regards). In any case, even when statistically significant, differences in medians and correlations for low sugar and low fat claims are rather small, and they may not be that important in practical terms.
|Illustration 1: Nutrition claims on yogurts|
|Claim »||Low sugar||Low fat||High fiber|
|U (p)||4982.05||( .000 )||8355.5||( .000 )||480.0||( .000 )|
|rho (p)||-.186||( .000 )||-.223||( .000 )||-.225||( .000 )|
|(Sig ≤ 0.05, 2-tailed; source: Perezgonzalez, 2011b2)|
A stratified sample of 342 yogurts (ie, soy and cow's milk yogurts, natural and flavored yogurts, and fat-free, low-fat, standard and creamy yogurts), collected in a convenient manner (see Perezgonzalez, 2011b2).
The grouping (or independent) variables were whether products sported nutrition-related claims such as high-fiber, low-fat, low-sugar and low-sodium.
- The distribution of the BNI variable was significantly non-normal and some groups were too small in size. The variables did however relate linearly with the dependent variable (BNI). In any case, a non-parametric approach was used for data analysis.
- Main analyses: tests of significance (Fisher-Perez's approach) based on sig ≤ 0.05 (ie, results falling within the 5% or more extreme probabilities area), 2-tailed.
- Main tests: Mann-Whitney U test for equality of ranked distributions of independent groups, Spearman's rho correlations, and multiple regression on ranked data.
- All analyses were carried out with SPSS-v18 (PASW Statistics 18).
Most yogurts 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):
- Internationally, if one assumes breakfast products to be of approximately similar nutritional composition anywhere.
Want to know more?
- BNI™ journal (2012, issue 1) - Yogurts galore
- This issue of the Balanced Nutrition Index™ journal collates all BNI™ nutrition information about the original sample in a single book. You can also access information about individual yogurts on the BNI™ database and aggregated information on Wiki of Science (nutritional balance of food).
- Wiki of Science - Nutrition topics
- This Wiki of Science page provides access to a variety of nutrition topics, including research related to the one summarised above and a related article providing an in-depth description of above results.
Jose D PEREZGONZALEZ (2012). Massey University, Turitea Campus, Private Bag 11-222, Palmerston North 4442, New Zealand. (JDPerezgonzalez).