Nutritional indices

In many studies of Insect dietetics, nutritional Indices have been... 

Three of the most useful nutritional indices are assimilation (AD), efficiency of conversion of assimilated food (ECD), and efficiency of conversion of Ingested food (ECI). These and a number of other indices were recently discussed by Scriber and Slansky (22). If growth is inhibited, then it must either be reflected in the amount eaten or in one or more of these Indices or both. 

The effects on nutritional indices can demonstrate an interaction between an allelochemlc and the nutritional status of the insect, but the number of actual compound-to-compound interactions that have been elucidated in Insects has been small. One of the most prominent examples is the structural analog of L-arginine, L-canavanine (see paper by G. A. Rosenthal in this symposium). Briefly, canavanlne is similar enough to arginine to be incorporated into the proteins of most insects, but these canavanyl proteins do not function properly (23). Thus, It can act as a competitive inhibitor of arginine metabolism (24, 25),... 

American Academy of Pediatrics Committee on Nutrition Indication for cholesterol testing in children. Pediatrics 1989 83 141-2. 

Manili L, Camerini C, et al. Predictive value of dialysis adequacy and nutritional indices for mortality and morbidity in CAPD and HD patients. A longitudinal study. Nephrol Dial Transplant 1995 10 2295-305. 

Relationships between heat processing and nutritional indicators of SFs are shown in Table 19.3. Increased heating reduces TI activity, which is reflected in lessened enlargement of the pancreas in test rats. Although minimum protein denaturation is desired to maximize SF solubility and functionality, the fabricated product must be adequately cooked before consumption (Fulmer, 1989a). 

Cousins. R.J. (1982). Mechanism of zinc absorption, in Prasad AS, Ed. Clinical, Biochemical and Nutritional Indices of Trace Elements, p.3, Alan Liss, New York. 

Reese, J. C. and Beck, S. D. (1978) Inter-relationships of nutritional indices and dietary moisture in the black cutworm (Agrotis ipsilon) digestive efficiency. J. Insect Physiol., 24, 473-9. 

Krasinski, S.D., Russell, R.M., Samlolf, I.M., Jacob, R.A., Dallal, G.E., McGandy, R.B., and Hartz, S.C., 1986. Fundic atrophic gastritis in an elderly population effect on hemoglobin and several serum nutritional indicators. Journal of the American Geriatrics Society. 34 800-806. 

The formulation of nutritional indices starts with the fundamental premise that the total mass of food ingested (7) can be partitioned into three quantities the mass excreted in feces F), the mass metabolized during respiration (M), and the mass incorporated into herbivore biomass B). From the basic equation, B = I -F - M, several rates and efficiencies can be calculated (Table 5.3), and the terminology has been reviewed extensively (e.g., Slansky Scriber 1985 Kogan 1986 Farrar et al. 1989 Raubenheimer Simpson 1992). 

Data for calculation of nutritional analyses are much the same for all methods of statistical analysis described above. Basic precautionary steps recommended for selection of individuals, pretest conditions, and standardization of both test animals and test diets have been discussed elsewhere (Berenbaum 1986). Nutritional indices are extremely sensitive to small errors in computation (Schmidt Reese 1986 Stamp 1991), thus, efforts to reduce such sources of variation are of utmost importance in such studies. All consumption experiments must provide food ad libitum unless effects of starvation are being tested, and careful planning and some preliminary experiments may be required to determine how much food must be prepared or obtained in advance to complete the entire experiment. This is especially important when insects are to be tested on plant food to avoid introducing variation in food quality due to difference in plant or leaf age into the experimental design. 

After consumption is determined in this way, then all other nutritional indices can be calculated as described above. 

Raubenheimer, D. S.J. Simpson. 1992. Analysis of covariance—an alternative to nutritional indices. Entomol. Exp. Appl. 62 221-231. 

---