<?xml version="1.0" encoding="UTF-8"?>

<!--XBRL Document Created with the Workiva Platform-->
<!--Copyright 2026 Workiva-->
<!--r:019e74a1-161c-746e-88d7-2afcb53ec24d,g:5315ea8f-ad5d-42bf-ae59-cc0d9d3e9433-->
<link:linkbase xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd">
  <link:roleRef roleURI="http://www.medifast1.com/role/Cover" xlink:type="simple" xlink:href="med-20260529.xsd#Cover"/>
  <link:presentationLink xlink:role="http://www.medifast1.com/role/Cover" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_dei_CoverAbstract_019e74a1-161c-7a5b-8bca-42fb6f7f083e" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_CoverAbstract"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntitiesTable_019e74a1-161c-764c-a295-66c00684f0ba" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntitiesTable"/>
    <link:presentationArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_019e74a1-161c-7a5b-8bca-42fb6f7f083e" xlink:to="loc_dei_EntitiesTable_019e74a1-161c-764c-a295-66c00684f0ba" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityListingsExchangeAxis_019e74a1-161c-7fcb-96d3-926a05484a92" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityListingsExchangeAxis"/>
    <link:presentationArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_EntitiesTable_019e74a1-161c-764c-a295-66c00684f0ba" xlink:to="loc_dei_EntityListingsExchangeAxis_019e74a1-161c-7fcb-96d3-926a05484a92" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_ExchangeDomain_019e74a1-161c-71ce-91ec-0ac9971f4c9d" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_ExchangeDomain"/>
    <link:presentationArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_EntityListingsExchangeAxis_019e74a1-161c-7fcb-96d3-926a05484a92" xlink:to="loc_dei_ExchangeDomain_019e74a1-161c-71ce-91ec-0ac9971f4c9d" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_exch_XNYS_019e74a1-161c-7da8-b030-9e468f84745e" xlink:href="https://xbrl.sec.gov/exch/2025/exch-2025.xsd#exch_XNYS"/>
    <link:presentationArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_ExchangeDomain_019e74a1-161c-71ce-91ec-0ac9971f4c9d" xlink:to="loc_exch_XNYS_019e74a1-161c-7da8-b030-9e468f84745e" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityInformationLineItems_019e74a1-161c-7f88-8210-be8f86db7538" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityInformationLineItems"/>
    <link:presentationArc order="2" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_EntitiesTable_019e74a1-161c-764c-a295-66c00684f0ba" xlink:to="loc_dei_EntityInformationLineItems_019e74a1-161c-7f88-8210-be8f86db7538" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentType_019e74a1-161c-7837-ba47-da01e4feed6d" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentType"/>
    <link:presentationArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_EntityInformationLineItems_019e74a1-161c-7f88-8210-be8f86db7538" xlink:to="loc_dei_DocumentType_019e74a1-161c-7837-ba47-da01e4feed6d" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentPeriodEndDate_019e74a1-161c-77b6-a672-282f176ab298" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentPeriodEndDate"/>
    <link:presentationArc order="2" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_EntityInformationLineItems_019e74a1-161c-7f88-8210-be8f86db7538" xlink:to="loc_dei_DocumentPeriodEndDate_019e74a1-161c-77b6-a672-282f176ab298" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityRegistrantName_019e74a1-161c-7da4-a6d4-592884effe07" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityRegistrantName"/>
    <link:presentationArc order="3" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_EntityInformationLineItems_019e74a1-161c-7f88-8210-be8f86db7538" xlink:to="loc_dei_EntityRegistrantName_019e74a1-161c-7da4-a6d4-592884effe07" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressAddressLine1_019e74a1-161c-7795-b341-ab7ba3df3fcc" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityAddressAddressLine1"/>
    <link:presentationArc order="4" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_EntityInformationLineItems_019e74a1-161c-7f88-8210-be8f86db7538" xlink:to="loc_dei_EntityAddressAddressLine1_019e74a1-161c-7795-b341-ab7ba3df3fcc" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressCityOrTown_019e74a1-161c-7525-8f8b-474903679c5d" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityAddressCityOrTown"/>
    <link:presentationArc order="5" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_EntityInformationLineItems_019e74a1-161c-7f88-8210-be8f86db7538" xlink:to="loc_dei_EntityAddressCityOrTown_019e74a1-161c-7525-8f8b-474903679c5d" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressStateOrProvince_019e74a1-161c-7e49-b8f8-9ea1d38bd0ed" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityAddressStateOrProvince"/>
    <link:presentationArc order="6" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_EntityInformationLineItems_019e74a1-161c-7f88-8210-be8f86db7538" xlink:to="loc_dei_EntityAddressStateOrProvince_019e74a1-161c-7e49-b8f8-9ea1d38bd0ed" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressPostalZipCode_019e74a1-161c-76b1-b228-3c98d46e5534" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityAddressPostalZipCode"/>
    <link:presentationArc order="7" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_EntityInformationLineItems_019e74a1-161c-7f88-8210-be8f86db7538" xlink:to="loc_dei_EntityAddressPostalZipCode_019e74a1-161c-76b1-b228-3c98d46e5534" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_CityAreaCode_019e74a1-161c-72df-abb2-3bd03f1f4788" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_CityAreaCode"/>
    <link:presentationArc order="8" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_EntityInformationLineItems_019e74a1-161c-7f88-8210-be8f86db7538" xlink:to="loc_dei_CityAreaCode_019e74a1-161c-72df-abb2-3bd03f1f4788" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LocalPhoneNumber_019e74a1-161c-7211-9648-630e3ad8838b" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_LocalPhoneNumber"/>
    <link:presentationArc order="9" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_EntityInformationLineItems_019e74a1-161c-7f88-8210-be8f86db7538" xlink:to="loc_dei_LocalPhoneNumber_019e74a1-161c-7211-9648-630e3ad8838b" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_Security12bTitle_019e74a1-161c-753f-a1fe-04588162430d" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_Security12bTitle"/>
    <link:presentationArc order="10" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_EntityInformationLineItems_019e74a1-161c-7f88-8210-be8f86db7538" xlink:to="loc_dei_Security12bTitle_019e74a1-161c-753f-a1fe-04588162430d" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_TradingSymbol_019e74a1-161c-7813-bb81-ab6cdabab8ea" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_TradingSymbol"/>
    <link:presentationArc order="11" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_EntityInformationLineItems_019e74a1-161c-7f88-8210-be8f86db7538" xlink:to="loc_dei_TradingSymbol_019e74a1-161c-7813-bb81-ab6cdabab8ea" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_SecurityExchangeName_019e74a1-161c-787f-9c86-5dd459352cc2" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_SecurityExchangeName"/>
    <link:presentationArc order="12" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_EntityInformationLineItems_019e74a1-161c-7f88-8210-be8f86db7538" xlink:to="loc_dei_SecurityExchangeName_019e74a1-161c-787f-9c86-5dd459352cc2" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_WrittenCommunications_019e74a1-161c-7634-b7b0-31f58e3a7ab6" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_WrittenCommunications"/>
    <link:presentationArc order="13" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_EntityInformationLineItems_019e74a1-161c-7f88-8210-be8f86db7538" xlink:to="loc_dei_WrittenCommunications_019e74a1-161c-7634-b7b0-31f58e3a7ab6" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_SolicitingMaterial_019e74a1-161c-7a38-ae27-6786b94fbc38" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_SolicitingMaterial"/>
    <link:presentationArc order="14" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_EntityInformationLineItems_019e74a1-161c-7f88-8210-be8f86db7538" xlink:to="loc_dei_SolicitingMaterial_019e74a1-161c-7a38-ae27-6786b94fbc38" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_PreCommencementTenderOffer_019e74a1-161c-782c-ba9f-74c61b6c7879" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_PreCommencementTenderOffer"/>
    <link:presentationArc order="15" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_EntityInformationLineItems_019e74a1-161c-7f88-8210-be8f86db7538" xlink:to="loc_dei_PreCommencementTenderOffer_019e74a1-161c-782c-ba9f-74c61b6c7879" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_PreCommencementIssuerTenderOffer_019e74a1-161c-7f2d-a192-23571e257d8b" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_PreCommencementIssuerTenderOffer"/>
    <link:presentationArc order="16" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_EntityInformationLineItems_019e74a1-161c-7f88-8210-be8f86db7538" xlink:to="loc_dei_PreCommencementIssuerTenderOffer_019e74a1-161c-7f2d-a192-23571e257d8b" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityEmergingGrowthCompany_019e74a1-161c-7aa9-ad4f-df0270e2ab83" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityEmergingGrowthCompany"/>
    <link:presentationArc order="17" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_EntityInformationLineItems_019e74a1-161c-7f88-8210-be8f86db7538" xlink:to="loc_dei_EntityEmergingGrowthCompany_019e74a1-161c-7aa9-ad4f-df0270e2ab83" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityCentralIndexKey_019e74a1-161c-7d3e-a81e-cb9775f285aa" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityCentralIndexKey"/>
    <link:presentationArc order="18" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_EntityInformationLineItems_019e74a1-161c-7f88-8210-be8f86db7538" xlink:to="loc_dei_EntityCentralIndexKey_019e74a1-161c-7d3e-a81e-cb9775f285aa" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_AmendmentFlag_019e74a1-161c-740f-bea1-4bbfe9c1eb43" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_AmendmentFlag"/>
    <link:presentationArc order="19" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_EntityInformationLineItems_019e74a1-161c-7f88-8210-be8f86db7538" xlink:to="loc_dei_AmendmentFlag_019e74a1-161c-740f-bea1-4bbfe9c1eb43" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityTaxIdentificationNumber_019e74a1-161c-775c-bc80-0cd4d9d3d113" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityTaxIdentificationNumber"/>
    <link:presentationArc order="20" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_EntityInformationLineItems_019e74a1-161c-7f88-8210-be8f86db7538" xlink:to="loc_dei_EntityTaxIdentificationNumber_019e74a1-161c-775c-bc80-0cd4d9d3d113" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityFileNumber_019e74a1-161c-751e-88c2-cbd8977d8b98" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityFileNumber"/>
    <link:presentationArc order="21" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_EntityInformationLineItems_019e74a1-161c-7f88-8210-be8f86db7538" xlink:to="loc_dei_EntityFileNumber_019e74a1-161c-751e-88c2-cbd8977d8b98" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityIncorporationStateCountryCode_019e74a1-161c-744c-9163-b5078898a013" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityIncorporationStateCountryCode"/>
    <link:presentationArc order="22" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_EntityInformationLineItems_019e74a1-161c-7f88-8210-be8f86db7538" xlink:to="loc_dei_EntityIncorporationStateCountryCode_019e74a1-161c-744c-9163-b5078898a013" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
  </link:presentationLink>
</link:linkbase>
