# GNUtrition 0.33.0rc5

Anton McClure <asm@gnu.org>
Edgar Denny
Ian Haywood

June 02, 2026

## Introduction

GNUtrition is a program designed to produce a detailed nutritional analysis of the human diet.

### Downloading GNUtrition

GNUtrition is is freely available at www.gnu.org. It is released under the GNU General Public Licence version 3 or later. See the file `LICENCE` for details.

#### Requirements

GNUtrition requires the following packages:

Build-time

- GNU Make

- C compiler with C99 support (e.g., GCC)

- GTK 3.0+ development headers and library

- sqlite3 development headers and library

- libm (typically part of the C standard library on GNU/Linux)

Run-time

- GTK 3.0+ library

- sqlite3 library

- A USDA food database (included with tarball as of 0.33.0rc3).

This list looks daunting, but all of these packages should be standard on modern GNU systems, but you may have to install SQLite separately.

### Running GNUtrition for the First Time

Install the database used for food information first:

    $./build_db.sh

Then you can start GNUtrition for the command-line simply:

    $gnutrition

#### Entering your Information

The profile options give you the option to enter your age in years, your current height, your current weight, and your activity level. This is subject to change prior to GNUtrition 1.0.

## The Main Window

The main window shows you a daily budget based on USDA recommendations, along with the following options

- s `Search`

- l `Log`

- p `Profile`

- q `Quit`

The search tool lets you search by food names and descriptions.

The log lets you view foods you add, and lets you edit those entries.

## The Main GUI Window

At the top of the new main window is Search, Profile, and About.

Under that, you have both a daily budget based on USDA recommendations, along a daily food log.

The search window lets you search by food names and descriptions.

## The Nutrients in GNUtrition

This chapter contains some notes on the nutrients analysed by GNUtrition. They are not a definitive guide, for detailed information refer to a standard text of nutrition or dietetics.

### Caveat

When Ian was researching the information for the Recommended Daily Intakes (RDIs). he found the information conflicting but incomplete, so for some nutrients there may be a European value, a US value, and a UN value. In general, he chose the US value, in the hope this will be compatible with the database.

If you know of a good reference for RDIs, we would be eager to hear from you, mail us at bug-gnutrition@gnu.org

It also should be noted that RDIs are a guide to nutrition, not the definition of it. Individuals may vary from the RDIs provided for many reasons. For example, active people need more energy and protein than inactive people, and illness increases the RDIs for almost everything.

In summary, just because the program spits out a nice column of “100%”, that doesn’t automatically mean you have a healthy diet. The old rules about balance and lots of green vegetables still apply, we’re afraid.

### Macro nutrients

Macro nutrients constitute the bulk of the food we eat, they provide energy and chemical building-blocks for tissues.

Protein

  Proteins consists of long chains of amino acids, to which it is broken down to in the digestive system. Much of these amino acids are reconstituted by the body to form human proteins. Human proteins are universal in the body: as enzymes they regulate chemical reactions within cells and the blood, they form tendons and ligaments which hold the body together, and they provide muscle with its ability to contract. Excess protein can be converted to sugar by the liver.

Carbohydrate

  consists of sugar, and chains of sugar molecules called starches. Starches are broken down in a similar manner to protein. In plants and bacteria, carbohydrates provide structure, but in animals they are used for energy.

Fat

  consists of fatty acids (lipids), which are chain of carbon atoms with a acid group at the end. These fatty acids are linked in groups of three by glycerol. Once again,. this structure is broken down in the gut, only to be re-formed in fat cells. Some fatty acids have special functions, but mostly fat is a store of energy.

Alcohol

  Rightfully a drug, but its energy component, between fat and protein, can be significant in some people. There is no recommended intake for alcohol, but their are recommended maximum intakes, these being 40g a day for men and 20g a day for women.
  [according to the Drug and Alcohol Centre, St. Vincent’s Hospital, Melbourne, Australia.]

Energy

  A total calculated from the above, which is expressed in both kilocalories (the traditional unit in chemistry), and kilojoules (the physicist’s unit).
  There is a base requirement for energy, which can be estimated by age and weight. However, muscle mass requires more energy to maintain than fat mass, so persons of the same weight can have widely different base energy requirements. In addition, active people will obviously need more energy.

Fibre

  is indigestible by human enzymes, and is largely excreted, or digested by bacteria in the large intestine. Nevertheless, it is very important, and often deficient in first-world diets. It dilutes toxins that build up the gut and retains water. It softens faeces and increases its volume, making bowel motions more efficient. Deficiency causes constipation, and has been linked to bowel cancer.

Water

  Arguably the most important nutrient, in terms of amount (two-thirds of the body), and essentiality (people die of thirst long before they starve).

### Vitamins

Vitamins are cofactors – special molecules which support various biochemical reactions with in the body – required only in very small amounts, and can be stored for extended periods. They are divided into two groups:

#### Fat-soluble vitamins

Vitamin A

  is used for light-detecting chemicals in the retina of the eye, and maintaining proper skin moisture and softness. In deficiency, poor night vision, hard and rough skin, and anaemia can occur. Vitamin A is also an anti-oxidant and protects against cancer.

Vitamin D

  regulates calcium. Deficiency leads to rickets (soft, malformed bones) in children. With adequate sunlight, the body can make its own vitamin D, so little or none is required by the diet. It is not included in the USDA database, and so not analysed by GNUtrition.

Vitamin E

  is a strong anti-oxidant: it destroys cancer-causing chemicals called free radicals. No deficiency syndrome has been described.

Vitamin K

  is used by the liver to make special proteins, which circulate in the blood. When a person is injured, these proteins. help to form a clot. Intestinal bacteria can make vitamin K, however, it is also required in the diet, but in low amounts. It is not included in the database.

#### Water-soluble vitamins

Vitamin C

  is used in making collagen, a tough protein that provides a “glue” holding cells together. Vitamin C deficiency, known as scurvy, leads to easy bruising and bleeding, as lack of collagen weakens blood vessels. It also aids the absorption of of iron, and may be an anti-oxidant.
  It is not a cure for the common cold.

Vitamin B-1 (Thiamine)

  is used in the biochemical processes by which cells obtain energy from sugar. Deficiency causes mental disturbance, clumsiness, and double-vision, which can occur in alcoholics, and in third-world countries.

Riboflavin; Niacin; Pantothenic acid

  are also important in energy utilisation by cells, by forming parts of different enzymes. Niacin deficiency causes pellagra, characterised to dermatitis, diarrhoea, and dementia.

Vitamin B-6 (pyridoxine)

  is used for processing of amino acids, deficiency causes a type of anaemia.

Folate

  is used for the synthesis of DNA. Deficiency leads to anaemia. In pregnant women, higher intakes protects against neural tube defects in their children.

Vitamin B-12

  is also used for DNA synthesis, also leads to anaemia when deficient. Only available in animal sources, so strict vegans require supplementation.

### Metals

Iron

  is used mainly in haemoglobin, a chemical that binds oxygen in the blood, giving it its red colour. Deficiency, more common in women, leads to mild anaemia.

Calcium

  is used mainly in bones, to provide mechanical strength. Low calcium intake has been linked to osteoporosis (weakening of the bones) in old people.

Selenium

  is essential to an anti-oxidant enzyme, which works in a similar manner to Vitamin E.

Potassium; Sodium

  are used to provide electrical potentials across nerve and muscle cell membranes, also to provide the necessary osmotic force in body fluids. Excess sodium was once linked to high blood pressure, but this not emphasised today.

Magnesium

  is used in controlling nerve impulses, deficiency causes weakness and tremors.

Copper; Manganese; Zinc

  combine with specific proteins to form various different enzymes.

### Amino acids

Amino acids are the breakdown products of proteins. They are divided into two groups, essential and non-essential:

Essential | Non-essential
--- | ---
Histidine | Glycine
Isoleucine | Glutamate
Leucine | Aspartate
Lysine | Proline
Methionine | Serine
Phenylalanine | Alanine
Threonine | Tryptophan
Tryptophan | Arginine
Valine |

Deficiency of any of the nine leads to wasting as proteins cannot be made without them. This usually only occurs with a very monotonous vegan diet, where the chief food is a plant that does not have one or more essential amino acid. A varied vegetarian diet solves the problem.

The other amino acids can be synthesised by the liver. The liver can also interchange two pairs: cysteine and methionine, and tyrosine and phenylalanine. This means a shortage of one can be made up from the other, so total as the total requirement is met.

Amino acid supplements are of no proven benefit over proteins containing the amino acids (but are much more expensive).

### Lipids

Lipids include fatty acids (breakdown products of fat) and cholesterol.

Fatty acids

  can be divided into three main groups: saturated
  [‘saturation’ in this sense refers to hydrogen. Ask an organic chemist.]
  , mono-unsaturated and polyunsaturated. With these three the key is the ratio – lots of saturated fatty acids, relative to the others leads to atherosclerosis (hardening of the arteries).
  Their specific chemical structures are available in organic chemistry or biochemistry textbooks, in general they consists of a vary chain of carbon-atoms, with a carboxylic acid group at one end.
  Fatty acids are used to make certain types of hormones, as well as to store energy. Two fatty acids, linoleic and alpha-linoleic acid, are essential for humans.

Omega-3, and -6

  Some fatty acids are referred as "omega-3" and "omega-6". This refers to the location of a double bond from the final (omega) carbon atom in the fatty acid.
  It is believed that omega-3 fatty acids, found in fish oil, may have beneficial health effects, but there is little hard evidence for this.

Cholesterol

  can be made by the liver, so there is little dietary need. When we eat cholesterol, the liver compensates by making less. Contrary to popular belief, dietary cholesterol seems to have little effect on blood-cholesterol levels, instead saturated fatty acids seem to be more important.

Phytosterols

  Not sure about these. Many be one and the same as phyto-oestrogens, plant mimics of the female sex hormone. Intake is believed to control symptoms of menopause.

## GNU Free Documentation License

Version 1.1, March 2000

    Copyright © 2000 Free Software Foundation, Inc.
    <http://fsf.org/>

    Everyone is permitted to copy and distribute verbatim copies
    of this license document, but changing it is not allowed.

1. PREAMBLE

   The purpose of this License is to make a manual, textbook, or other written document free in the sense of freedom: to assure everyone the effective freedom to copy and redistribute it, with or without modifying it, either commercially or noncommercially. Secondarily, this License preserves for the author and publisher a way to get credit for their work, while not being considered responsible for modifications made by others.

   This License is a kind of “copyleft”, which means that derivative works of the document must themselves be free in the same sense. It complements the GNU General Public License, which is a copyleft license designed for free software.

   We have designed this License in order to use it for manuals for free software, because free software needs free documentation: a free program should come with manuals providing the same freedoms that the software does. But this License is not limited to software manuals; it can be used for any textual work, regardless of subject matter or whether it is published as a printed book. We recommend this License principally for works whose purpose is instruction or reference. . APPLICABILITY AND DEFINITIONS

   This License applies to any manual or other work that contains a notice placed by the copyright holder saying it can be distributed under the terms of this License. The “Document”, below, refers to any such manual or work. Any member of the public is a licensee, and is addressed as “you”.

   A “Modified Version” of the Document means any work containing the Document or a portion of it, either copied verbatim, or with modifications and/or translated into another language.

   A “Secondary Section” is a named appendix or a front-matter section of the Document that deals exclusively with the relationship of the publishers or authors of the Document to the Document’s overall subject (or to related matters) and contains nothing that could fall directly within that overall subject. (For example, if the Document is in part a textbook of mathematics, a Secondary Section may not explain any mathematics.) The relationship could be a matter of historical connection with the subject or with related matters, or of legal, commercial, philosophical, ethical or political position regarding them.

   The “Invariant Sections” are certain Secondary Sections whose titles are designated, as being those of Invariant Sections, in the notice that says that the Document is released under this License.

   The “Cover Texts” are certain short passages of text that are listed, as Front-Cover Texts or Back-Cover Texts, in the notice that says that the Document is released under this License.

   A “Transparent” copy of the Document means a machine-readable copy, represented in a format whose specification is available to the general public, whose contents can be viewed and edited directly and straightforwardly with generic text editors or (for images composed of pixels) generic paint programs or (for drawings) some widely available drawing editor, and that is suitable for input to text formatters or for automatic translation to a variety of formats suitable for input to text formatters. A copy made in an otherwise Transparent file format whose markup has been designed to thwart or discourage subsequent modification by readers is not Transparent. A copy that is not “Transparent” is called “Opaque”.

   Examples of suitable formats for Transparent copies include plain ASCII without markup, Texinfo input format, LaTeX input format, SGML or XML using a publicly available DTD, and standard-conforming simple HTML designed for human modification. Opaque formats include PostScript, PDF, proprietary formats that can be read and edited only by proprietary word processors, SGML or XML for which the DTD and/or processing tools are not generally available, and the machine-generated HTML produced by some word processors for output purposes only.

   The “Title Page” means, for a printed book, the title page itself, plus such following pages as are needed to hold, legibly, the material this License requires to appear in the title page. For works in formats which do not have any title page as such, “Title Page” means the text near the most prominent appearance of the work’s title, preceding the beginning of the body of the text. . VERBATIM COPYING

   You may copy and distribute the Document in any medium, either commercially or noncommercially, provided that this License, the copyright notices, and the license notice saying this License applies to the Document are reproduced in all copies, and that you add no other conditions whatsoever to those of this License. You may not use technical measures to obstruct or control the reading or further copying of the copies you make or distribute. However, you may accept compensation in exchange for copies. If you distribute a large enough number of copies you must also follow the conditions in section 3.

   You may also lend copies, under the same conditions stated above, and you may publicly display copies. . COPYING IN QUANTITY

   If you publish printed copies of the Document numbering more than 100, and the Document’s license notice requires Cover Texts, you must enclose the copies in covers that carry, clearly and legibly, all these Cover Texts: Front-Cover Texts on the front cover, and Back-Cover Texts on the back cover. Both covers must also clearly and legibly identify you as the publisher of these copies. The front cover must present the full title with all words of the title equally prominent and visible. You may add other material on the covers in addition. Copying with changes limited to the covers, as long as they preserve the title of the Document and satisfy these conditions, can be treated as verbatim copying in other respects.

   If the required texts for either cover are too voluminous to fit legibly, you should put the first ones listed (as many as fit reasonably) on the actual cover, and continue the rest onto adjacent pages.

   If you publish or distribute Opaque copies of the Document numbering more than 100, you must either include a machine-readable Transparent copy along with each Opaque copy, or state in or with each Opaque copy a publicly-accessible computer-network location containing a complete Transparent copy of the Document, free of added material, which the general network-using public has access to download anonymously at no charge using public-standard network protocols. If you use the latter option, you must take reasonably prudent steps, when you begin distribution of Opaque copies in quantity, to ensure that this Transparent copy will remain thus accessible at the stated location until at least one year after the last time you distribute an Opaque copy (directly or through your agents or retailers) of that edition to the public.

   It is requested, but not required, that you contact the authors of the Document well before redistributing any large number of copies, to give them a chance to provide you with an updated version of the Document. . MODIFICATIONS

   You may copy and distribute a Modified Version of the Document under the conditions of sections 2 and 3 above, provided that you release the Modified Version under precisely this License, with the Modified Version filling the role of the Document, thus licensing distribution and modification of the Modified Version to whoever possesses a copy of it. In addition, you must do these things in the Modified Version:

   1. Use in the Title Page (and on the covers, if any) a title distinct from that of the Document, and from those of previous versions (which should, if there were any, be listed in the History section of the Document). You may use the same title as a previous version if the original publisher of that version gives permission.

   2. List on the Title Page, as authors, one or more persons or entities responsible for authorship of the modifications in the Modified Version, together with at least five of the principal authors of the Document (all of its principal authors, if it has less than five).

   3. State on the Title page the name of the publisher of the Modified Version, as the publisher.

   4. Preserve all the copyright notices of the Document.

   5. Add an appropriate copyright notice for your modifications adjacent to the other copyright notices.

   6. Include, immediately after the copyright notices, a license notice giving the public permission to use the Modified Version under the terms of this License, in the form shown in the Addendum below.

   7. Preserve in that license notice the full lists of Invariant Sections and required Cover Texts given in the Document’s license notice.

   8. Include an unaltered copy of this License.

   9. Preserve the section entitled “History”, and its title, and add to it an item stating at least the title, year, new authors, and publisher of the Modified Version as given on the Title Page. If there is no section entitled “History” in the Document, create one stating the title, year, authors, and publisher of the Document as given on its Title Page, then add an item describing the Modified Version as stated in the previous sentence.

   10. Preserve the network location, if any, given in the Document for public access to a Transparent copy of the Document, and likewise the network locations given in the Document for previous versions it was based on. These may be placed in the “History” section. You may omit a network location for a work that was published at least four years before the Document itself, or if the original publisher of the version it refers to gives permission.

   11. In any section entitled “Acknowledgments” or “Dedications”, preserve the section’s title, and preserve in the section all the substance and tone of each of the contributor acknowledgments and/or dedications given therein.

   12. Preserve all the Invariant Sections of the Document, unaltered in their text and in their titles. Section numbers or the equivalent are not considered part of the section titles.

   13. Delete any section entitled “Endorsements”. Such a section may not be included in the Modified Version.

   14. Do not retitle any existing section as “Endorsements” or to conflict in title with any Invariant Section.

       If the Modified Version includes new front-matter sections or appendices that qualify as Secondary Sections and contain no material copied from the Document, you may at your option designate some or all of these sections as invariant. To do this, add their titles to the list of Invariant Sections in the Modified Version’s license notice. These titles must be distinct from any other section titles.

       You may add a section entitled “Endorsements”, provided it contains nothing but endorsements of your Modified Version by various parties—for example, statements of peer review or that the text has been approved by an organization as the authoritative definition of a standard.

       You may add a passage of up to five words as a Front-Cover Text, and a passage of up to 25 words as a Back-Cover Text, to the end of the list of Cover Texts in the Modified Version. Only one passage of Front-Cover Text and one of Back-Cover Text may be added by (or through arrangements made by) any one entity. If the Document already includes a cover text for the same cover, previously added by you or by arrangement made by the same entity you are acting on behalf of, you may not add another; but you may replace the old one, on explicit permission from the previous publisher that added the old one.

       The author(s) and publisher(s) of the Document do not by this License give permission to use their names for publicity for or to assert or imply endorsement of any Modified Version. . COMBINING DOCUMENTS

       You may combine the Document with other documents released under this License, under the terms defined in section 4 above for modified versions, provided that you include in the combination all of the Invariant Sections of all of the original documents, unmodified, and list them all as Invariant Sections of your combined work in its license notice.

       The combined work need only contain one copy of this License, and multiple identical Invariant Sections may be replaced with a single copy. If there are multiple Invariant Sections with the same name but different contents, make the title of each such section unique by adding at the end of it, in parentheses, the name of the original author or publisher of that section if known, or else a unique number. Make the same adjustment to the section titles in the list of Invariant Sections in the license notice of the combined work.

       In the combination, you must combine any sections entitled “History” in the various original documents, forming one section entitled “History”; likewise combine any sections entitled “Acknowledgments”, and any sections entitled “Dedications”. You must delete all sections entitled “Endorsements.” . COLLECTIONS OF DOCUMENTS

       You may make a collection consisting of the Document and other documents released under this License, and replace the individual copies of this License in the various documents with a single copy that is included in the collection, provided that you follow the rules of this License for verbatim copying of each of the documents in all other respects.

       You may extract a single document from such a collection, and distribute it individually under this License, provided you insert a copy of this License into the extracted document, and follow this License in all other respects regarding verbatim copying of that document. . AGGREGATION WITH INDEPENDENT WORKS

       A compilation of the Document or its derivatives with other separate and independent documents or works, in or on a volume of a storage or distribution medium, does not as a whole count as a Modified Version of the Document, provided no compilation copyright is claimed for the compilation. Such a compilation is called an “aggregate”, and this License does not apply to the other self-contained works thus compiled with the Document, on account of their being thus compiled, if they are not themselves derivative works of the Document.

       If the Cover Text requirement of section 3 is applicable to these copies of the Document, then if the Document is less than one quarter of the entire aggregate, the Document’s Cover Texts may be placed on covers that surround only the Document within the aggregate. Otherwise they must appear on covers around the whole aggregate. . TRANSLATION

       Translation is considered a kind of modification, so you may distribute translations of the Document under the terms of section 4. Replacing Invariant Sections with translations requires special permission from their copyright holders, but you may include translations of some or all Invariant Sections in addition to the original versions of these Invariant Sections. You may include a translation of this License provided that you also include the original English version of this License. In case of a disagreement between the translation and the original English version of this License, the original English version will prevail. . TERMINATION

       You may not copy, modify, sublicense, or distribute the Document except as expressly provided for under this License. Any other attempt to copy, modify, sublicense or distribute the Document is void, and will automatically terminate your rights under this License. However, parties who have received copies, or rights, from you under this License will not have their licenses terminated so long as such parties remain in full compliance. . FUTURE REVISIONS OF THIS LICENSE

       The Free Software Foundation may publish new, revised versions of the GNU Free Documentation License from time to time. Such new versions will be similar in spirit to the present version, but may differ in detail to address new problems or concerns. See http://www.gnu.org/licenses/.

       Each version of the License is given a distinguishing version number. If the Document specifies that a particular numbered version of this License “or any later version” applies to it, you have the option of following the terms and conditions either of that specified version or of any later version that has been published (not as a draft) by the Free Software Foundation. If the Document does not specify a version number of this License, you may choose any version ever published (not as a draft) by the Free Software Foundation.

## Bibliography

Robert Bateman, Hamlyn, Every Boy’s Handbook, 1960. David Bender and Arnold Bender, Oxford, Nutrition: A reference handbook, 1997.

Stephen G. Chancy, Wiley-Liss, Principles of Nutrition I & II, 1997.

Textbook of Biochemistry, Edited by Thomas Devlin. Lubert Stryer, W. H. Freeman, Biochemistry, 4th ed., 1995.

U.S. Department of Agriculture, Agricultural Research Service, _Nutrient Database of Standard Reference, Relase 21_ , 2008.