Chips, crisps & cravers' BNI (description)

This article is a meta-analysis carried out on nine samples of chips⁶, crisps⁷ and cravers⁸ described individually in other articles (see Perezgonzalez, 2012a¹_d⁴) but here combined for the purpose of such meta-analysis. This article provides descriptive information both about the combined sample of products under research (foodBNI) as well as about a hypothetical diet based on those products (dietBNI).

foodBNI

The distribution of nutritional balance is shown in illustration 1. The median was located at BNI 74.58 and the middle 68% of products were located between BNI 49 (P₁₆) and BNI 93 (P₈₄). There was a positive skewness (zSkew=2.69), probably due to a few highly unbalanced foods, some of which also appeared separated from the rest of the distribution. There was also a positive kurtosis (zKurt=2.54), indicative of a distribution more peaked than normal. Notwithstanding this, the mean (72.57) appears more balanced than the median, reflecting a negative ordinal skewness (RSkew=-3.55) for the group at large. That is, the majority of products appeared grouped towards the unbalanced end of the distribution, with a nice sloping towards more balanced products and an abrupt cliff towards more unbalanced products (the high values of the few extreme cases help explain the opposite direction between parametric and non-parametric skewness).

The distribution of nutritional balance varied according to the particular recommended dietary intakes (RDIs) of reference, although all followed a pattern similar to the one just described. This group of products appeared less unbalanced under Australia's, UK's, and US' RDIs than under WHO's RDIs.

Illustration 1: Food's nutritional balance distribution
		International RDIs
Scale	BNI	WHO	US/CAN	AUS/NZ	UK
=0
>0
≥10		1	5	1	7
≥20	5	16	14	9	13
≥30	10	10	16	14	9
≥40	15	14	30	28	30
≥50	26	26	30	36	33
≥60	25	17	39	42	40
≥70	34	32	26	29	28
≥80	40	39	17	14	13
≥90	13	14	5	9	9
≥100	11	10
≥110	3	3	3	3	3
≥120	3	3	2	2	2
≥130			1	1	1
≥140	2	2
≥150	1	1
≥160
≥170
≥180
≥190
≥200

Median	74.58	74.42	59.63	62.18	60.83
SPR	21.52	24.92	20.39	18.88	19.60
P₁₆	49.51	42.59	36.32	41.97	40.34
P₈₄	92.55	92.42	77.09	79.73	79.54
RSkew	-3.55	-6.92	-2.93	-1.33	-0.89

Mean	72.57	69.86	58.96	61.93	60.40
StDev	23.39	26.01	21.88	20.03	21.45
zSkew	2.69	1.38	1.88	2.90	1.90
zKurt	2.54	1.07	1.64	2.74	1.87

Unstandardized	small	medium	large	( Avg.StDev )
effect size⁹	5	11	18	( 23 )

Correlations between indexes were high, thus supporting the idea of a common pattern in the distribution of nutritional balance across international indexes for this particular group of products.

Illustration 2: Correlations (Pearson and Spearman)
r / rho	BNI	WHO	US/CAN	AUS/NZ	UK
BNI		.989	.988	.985	.980
WHO	.986		.985	.962	.964
US/CAN	.993	.990		.982	.977
AUS/NZ	.989	.962	.983		.990
UK	.984	.967	.979	.990

dietBNI

As part of a hypothetical diet where all products contributed the same weight of chips, crisps and cravers, the resulting nutritional balance would improve slightly (more so under Australia's and UK's indexes, when attending to the unstandardized effect size for this group of products).

Illustration 3: Diet's nutritional balance
Protein	Carbs	Sugar	Fat	Sat.fat	Fiber	Sodium
6.5	58.3	3.1	25.1	8.4	0.9	0.734
International RDIs		BNI	WHO	US/CAN	AUS/NZ	UK
(diet)		66.84	66.24	52.19	52.32	50.05
(Values per 100g)

Methods

Research approach

Exploratory study for mapping the nutritional balance of chips, crisps and cravers in New Zealand.

Sample

A sample of 188 chip, crisp and craver products, including diverse brands and flavors, and other relevant categories. Relevant data were collated from previous research after visually ascertaining they shared a similar nutritional profile (see Perezgonzalez, 2012a¹_d⁴). Collating these related samples into one and performing further exploratory analyses help gain an overall view of the nutritional balance of these foods without being too affected by the small numbers of some of the subsamples.

Variables

Variables of interest for this research were the following:

Weight contribution of seven nutrients (protein, carbohydrate, sugar, fat, saturated fat, fiber and sodium) to 100g of a food product.
The Balanced Nutrition Index (BNI) of each food product, as calculated from above variables.
Aggregated information for the sample of products (foodBNI).
Aggregated information about the individual nutrients for the simulation of hypothetical diets (dietBNI).

Materials & analysis

Once collated, the data were assessed using the Balanced Nutrition Index™ (BNI™) technology (see Perezgonzalez, 2012e⁵).

SPSS-v18 was used for the computation of variables, including BNI and international indexes, and for descriptive statistical analyses.

References

1. PEREZGONZALEZ Jose D (2012a). Corn utopia. The Balanced Nutrition Index (ISSN 1177-8849), 2012, issue 6.

2. PEREZGONZALEZ Jose D (2012b). Tasty taytos. The Balanced Nutrition Index (ISSN 1177-8849), 2012, issue 5.

3. PEREZGONZALEZ Jose D (2012c). Crispy crisps. The Balanced Nutrition Index (ISSN 1177-8849), 2012, issue 7.

4. PEREZGONZALEZ Jose D (2012d). Yummy cravers. The Balanced Nutrition Index (ISSN 1177-8849), 2013, issue 1.

5. PEREZGONZALEZ Jose D (2012e). Balanced Nutrition Index™ (BNI™) (2e). Knowledge (ISSN 2324-1624), 2013, pages 38-40.

+++ Notes +++

6. They include both corn chips and potato chips.

7. Snacks made from extruded cereal or potato flour.

8. Savory crackers manufactured so as to compete in the same niche than chips and crisps.

9. This is the estimated unstandardized effect size for group differences (Cohen's d and Glass's Δ) given an average standard deviation and following Cohen's d effect size interpretation. It can be used to ascertain the relative importance of descriptive data without the need to perform inferential tests.

Want to know more?

WikiofScience - Chips, crisps & cravers (index): This WikiofScience page contains the full list of topics for chips, crisps and cravers, with links to the appropriate files.
WikiofScience - Nutritional balance of chips, crisps and cravers (further knowledge): Two WikiofScience pages provide further introductory and inferential information about the nutritional balance of chips, crisps and cravers.
WikiofScience - Nutritional balance of foods: This WikiofScience page collates information about several foods on a single page and provides useful links to the appropriate files.