<SEC-DOCUMENT>0001020859-17-000161.txt : 20171214
<SEC-HEADER>0001020859-17-000161.hdr.sgml : 20171214
<ACCEPTANCE-DATETIME>20171214161215
ACCESSION NUMBER:		0001020859-17-000161
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20171212
FILED AS OF DATE:		20171214
DATE AS OF CHANGE:		20171214

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			ROY PETER
		CENTRAL INDEX KEY:			0001239220

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-15723
		FILM NUMBER:		171256318

	MAIL ADDRESS:	
		STREET 1:		C/O WESTMARINE,
		STREET 2:		500 WESTRIDGE DRIVE
		CITY:			WATSONVILLE
		STATE:			CA
		ZIP:			95076

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			UNITED NATURAL FOODS INC
		CENTRAL INDEX KEY:			0001020859
		STANDARD INDUSTRIAL CLASSIFICATION:	WHOLESALE-GROCERIES & GENERAL LINE [5141]
		IRS NUMBER:				050376157
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			0730

	BUSINESS ADDRESS:	
		STREET 1:		313 IRON HORSE WAY
		CITY:			PROVIDENCE
		STATE:			RI
		ZIP:			02908
		BUSINESS PHONE:		401-528-8634

	MAIL ADDRESS:	
		STREET 1:		313 IRON HORSE WAY
		CITY:			PROVIDENCE
		STATE:			RI
		ZIP:			02908
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>wf-form4_151328592147419.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2017-12-12</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001020859</issuerCik>
        <issuerName>UNITED NATURAL FOODS INC</issuerName>
        <issuerTradingSymbol>UNFI</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001239220</rptOwnerCik>
            <rptOwnerName>ROY PETER</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O UNITED NATURAL FOODS, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>313 IRON HORSE WAY</rptOwnerStreet2>
            <rptOwnerCity>PROVIDENCE</rptOwnerCity>
            <rptOwnerState>RI</rptOwnerState>
            <rptOwnerZipCode>02908</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2017-12-12</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>2774</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>49.679</value>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>36864</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">The transaction price listed is a weighted average. Actual sale prices for these dispositions ranged from $49.67 to $49.68. The reporting person undertakes to provide United Natural Foods, Inc., any security holder of United Natural Foods, Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Joseph McGrail, Power-of-Attorney, in fact</signatureName>
        <signatureDate>2017-12-14</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
