biteR-package: biteR-package: Body Intake Estimation with R (NHANES)

In ToxStrategies/biteR: Body Intake Estimator (NHANES)

Description

Provides tools for evaluating population-level statistics for additive or nutrient intake based on NHANES dietary survey data. Functionality is also included to return non-survey weighted descriptive statistics on the size of the portion, per occasion.

biteR functions

There are 5 user-initiated functions in this package; see the help pages for documentation of each. These steps are separated out, eventually to support a front end in which each step might include its own parameterization and validation.

param.bite(file_name = "") creates and parameterizes a bite object with the input use levels and population demographics and intake data required for population estimation

raw.bite(Bite.obj) processes the new bite object to calculate NHANES participant's raw intake of the additive under study

pop.bite(Bite.obj) processes the raw bite object and produces age/gender/total reference population daily intake, incorporating survey sampling psu, strata, and weights.

The function bite(file_name = "") combines all three into one transaction, to generate population survey weighted descriptive statistics on the intake of a food additive.

The function bite.size(file_name = "") calls reduced functionality to estimate only the size of the meal eaten per occasion, i.e. including no survey weighted statistics on an additive consumed per day. Rather, bite.size() returns the size of the portion consumed of the input food codes, per eating occasion, e.g. the typical portion size of fish.

The 3 seperate or 2 combined functions produce statistics in strata with the following features:

cycles c("09", "11") NHANES cycle start years 2009 and 2011 are included in available data

age bands c("2-80", "2-5", "6-18", "19-80", "19-29", "30-44", "45-59", "60-80")

gender c("all", "female", "male")

per c("user", "all") refers to values by consumer of the use vs. all particpants in the dietary survey

adjust c("person", "kg") refers to information by person (no adjustment) vs. by kilo of body weight

rank c("mean", ".9") refers to calculating the mean and 90th percentile

These strata of intake information are produced for each use and for the total of all uses. The total does not duplicate intake for food codes assigned in multiple uses; only the use associated with the highest (proportion * use level) is included.

biteR input file format

The input file to param.bite(file_name = "") and the wrap-around function bite(file_name="") must be a .csv file with at least these columns:

Food_code An 8-digit food code

Proportion A numeric 0 < Proportion <= 1.0 indicating the proportion of the food relevant to the additive under study.

Use The category of use to sum population statistics by, e.g. "Yogurt" or "Ice_cream"

Use_level A numeric 0 < Use_level < 1.0 indicating the proportion of additive in the relevant fraction of the food. That is, the raw amount of additive consumed by a person is: grams of the Food_code * Proportion * Use_level.

In subsequent versions it is expected that these strata and features of the input file will be parameterizable by the user.

Bite.size() does not expect an input file with use_level, as additive intake is not estimated.

ToxStrategies/biteR documentation built on May 9, 2019, 5:12 p.m.