The balanced nutrition index (BNI™) is a technological application used for nutrition analysis and better communication about nutrition. It uses a set of dietary recommended intakes (RDIs) for analyzing and indexing food products, recipes and diets (Pérezgonzález, 2011a1). The RDIs that the BNI™ uses approach the average values of other, mostly Western, RDIs (Pérezgonzález, 2011b2). However, the technology itself can use any of those RDIs to obtain national indexes of balanced nutrition; it can even use such idiosyncratic nutritional standards as those decided by health organizations (eg, heart associations), weight management associations (eg, WeightWatches) or wannabes diets (eg the Atkins diet)3.
This article aims to explore the strengths and weaknesses of such technological approach to the analysis of food, recipes and diets.
- The BNI™ is a technological application which 'translates' a set of dietary standards into a mathematical formulation. Although the dietary standards may be less scientific than desired, the mathematical formulation itself is not affected by such wanderings. Therefore, the formulation and its technological application to indexing foods can be mathematically (thus, scientifically) and technologically sound despise using pseudoscientific nutrition standards.
- The BNI™ mathematical formula itself seems sound. It is based on basic mathematical functions, namely the calculation of percentage contribution of nutrients to 100 grams of food, the subtraction of such percentages from "ideal" RDIs percentage contributions to 100 grams of food of equivalent energetic content (based on a standard 2000 kilocalories diet), and the addition of all deviations from the standard RDIs (in natural numbers) into a single numerical value. As deviations are 'zero' when actual contribution equals "ideal" contribution, then a BNI™ 0.0 represents a balanced food or diet (as per RDIs), while larger than 'zero' BNI™ represent differing degree of nutritional deviation from "ideal" RDIs (thus, an increasingly unbalanced food or diet).
- The use of quasi-scientific4 RDIs may be posed as a refuting evidence against the scientific value of the BNI™. However, as said earlier, the mathematical formulation is not affected by the nature of the RDIs. If in the future a scientifically validated set of RDIs was found, its use in the formula may increase the perceived value of the index, not the soundness of the formula itself.
- A different thing is the scientific value of the index itself. As it uses pseudoscientific RDIs, then any nutrition assessment it makes is equally pseudoscientific. To this, two clarifications may be made:
- Firstly, RDIs are set nationally by a panel of experts on nutritional science, who, one expects, would have decided on a set of RDIs based on available scientific nutrition research, among other considerations. The fact that differing standards exist hints to a process that is less 'scientific' than desired; yet, the resulting RDIs may probably best the best 'empirical' solution for the nutritional needs of the national population at large at the time. Such 'empirical' solution can then be used as the nutritional standard of reference for a balanced diet nationally.
- Secondly, the BNI™ uses an average of several national RDIs, thus compensating for part of the problems discussed above when trying to obtain an international set of standards. This does not make it necessarily more valid, but it does make it a bit more 'scientific' by way of applying mathematics (ie, statistics) to it.
- Correlations between the BNI and other nutritional standards are normally high, and significantly so (which also supports the adequacy of the BNI™ as a 'representative' international standard):
Foods r WHO US/CAN AUS/NZ UK Chocolate (N=50) BNI™ 1.000 .775 .947 .961 (p) (.000) (.000) (.000) (.000) Cured meats (N=21) BNI™ .996 .978 .982 .976 (p) (.000) (.000) (.000) (.000) Milk & milk alternatives (N=107) BNI™ .981 .950 .996 .966 (p) (.000) (.000) (.000) (.000) Yogurt (N=342) BNI™ .878 .891 .998 .929 (p) (.000) (.000) (.000) (.000) Standard milks (N=12) BNI™ .891 .836 .950 .925 (p) (.000) (.001) (.000) (.000) Breakfast cereals (N=79) BNI™ .957 .960 .998 .938 (p) (.000) (.000) (.000) (.000) Liquid breakfast (N=14) BNI™ .963 .972 1.000 .974 (p) (.000) (.000) (.000) (.000) Potato chips (N=63) BNI™ 1.000 .983 .983 .983 (p) (.000) (.000) (.000) (.000) (Statistical significance set at the 0.05 level, 2-tailed)
|Illustration 1: Food's nutritional balance distribution (n=1052)|
Contributors to this page
Authors / Editors
Jose D PEREZGONZALEZ (2011). Massey University, New Zealand (JDPerezgonzalez).