npm package: @stdlib/datasets-fivethirtyeight-ffq
Description: FiveThirtyEight reader responses to a food frequency questionnaire (FFQ).
Author: The Stdlib Authors
Latest version: 0.2.3

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# FiveThirtyEight Food Frequency Questionnaire

[![NPM version][npm-image]][npm-url] [![Build Status][test-image]][test-url] [![Coverage Status][coverage-image]][coverage-url] <!-- [![dependencies][dependencies-image]][dependencies-url] -->

> [_FiveThirtyEight_][fivethirtyeight-nutrition-studies] reader responses to a food frequency questionnaire ([FFQ][ffq]).

<section class="installation">

## Installation

```bash
npm install @stdlib/datasets-fivethirtyeight-ffq
```

</section>

<section class="usage">

## Usage

```javascript
var dataset = require( '@stdlib/datasets-fivethirtyeight-ffq' );
```

#### dataset()

Returns [_FiveThirtyEight_][fivethirtyeight-nutrition-studies] reader responses to a food frequency questionnaire ([FFQ][ffq]).

```javascript
var data = dataset();
// returns [ {...}, ... ]
```

</section>

<!-- /.usage -->

<section class="notes">

## Notes

-   The administered food frequency questionnaire ([FFQ][ffq]) was the proprietary [Block FFQ][block-ffq].

</section>

<!-- /.examples -->

<section class="examples">

## Examples

<!-- eslint no-undef: "error" -->

```javascript
var bifurcateBy = require( '@stdlib/utils-bifurcate-by' );
var inmap = require( '@stdlib/utils-inmap' );
var ttest2 = require( '@stdlib/stats-ttest2' );
var dataset = require( '@stdlib/datasets-fivethirtyeight-ffq' );

function predicate( v ) {
    return ( v.diabetes === 1 );
}

function createAccessor( field ) {
    return accessor;

    function accessor( v ) {
        return v[ field ];
    }
}

// Retrieve the data:
var data = dataset();

// Split the data into two groups based on whether a respondent has diabetes:
var groups = bifurcateBy( data, predicate );

// For each group, extract the frequency of green salad consumption:
var mapFcn = createAccessor( 'greensaladfreq' );
var g1 = inmap( groups[ 0 ].slice(), mapFcn );
var g2 = inmap( groups[ 1 ].slice(), mapFcn );

// Perform a two-sample two-sided Student's t-test to determine if green salad consumption is different between the two groups:
var results = ttest2( g1, g2 );
console.log( results.print() );
```

</section>

<!-- /.examples -->



* * *

<section class="references">

## References

-   Aschwanden, Christie. 2016. "You Can't Trust What You Read About Nutrition." <https://fivethirtyeight.com/features/you-cant-trust-what-you-read-about-nutrition/>.

</section>

<!-- /.references -->

<!-- <license> -->

## License

The data files (databases) are licensed under an [Open Data Commons Attribution 1.0 License][odc-by-1.0] and their contents are licensed under a [Creative Commons Attribution 4.0 International Public License][cc-by-4.0]. The original dataset is attributed to _FiveThirtyEight_ and can be found [here][fivethirtyeight-nutrition-studies]. The software is licensed under [Apache License, Version 2.0][apache-license].

<!-- </license> -->

<!-- Section for related `stdlib` packages. Do not manually edit this section, as it is automatically populated. -->

<section class="related">

## See Also

-   <span class="package-name">[`@stdlib/datasets-fivethirtyeight-ffq-cli`][@stdlib/datasets-fivethirtyeight-ffq-cli]</span><span class="delimiter">: </span><span class="description">CLI package for use as a command-line utility.</span>


</section>

<!-- /.related -->

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<section class="main-repo" >

* * *

## Notice

This package is part of [stdlib][stdlib], a standard library for JavaScript and Node.js, with an emphasis on numerical and scientific computing. The library provides a collection of robust, high performance libraries for mathematics, statistics, streams, utilities, and more.

For more information on the project, filing bug reports and feature requests, and guidance on how to develop [stdlib][stdlib], see the main project [repository][stdlib].

#### Community

[![Chat][chat-image]][chat-url]

---

## Copyright

Copyright &copy; 2016-2026. The Stdlib [Authors][stdlib-authors].

</section>

<!-- /.stdlib -->

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[@stdlib/datasets-fivethirtyeight-ffq]: https://github.com/stdlib-js/datasets-fivethirtyeight-ffq/tree/main

[umd]: https://github.com/umdjs/umd
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[odc-by-1.0]: http://opendatacommons.org/licenses/by/1.0/

[cc-by-4.0]: http://creativecommons.org/licenses/by/4.0/

[apache-license]: https://www.apache.org/licenses/LICENSE-2.0

[csv]: https://tools.ietf.org/html/rfc4180

[fivethirtyeight-nutrition-studies]: https://fivethirtyeight.com/features/you-cant-trust-what-you-read-about-nutrition/

[block-ffq]: https://nutritionquest.com/assessment/list-of-questionnaires-and-screeners/

[ffq]: https://en.wikipedia.org/wiki/Food_frequency_questionnaire

</section>

<!-- /.links -->