-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
 EUxit7DfcY1gAb/7GRgnZrIx+kpC1SEDlrie2x6MM2nwepCjcHnPskAgMMCI6Kqq
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<SEC-DOCUMENT>0001420506-10-000071.txt : 20100617
<SEC-HEADER>0001420506-10-000071.hdr.sgml : 20100617
<ACCEPTANCE-DATETIME>20100617214148
ACCESSION NUMBER:		0001420506-10-000071
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20080731
FILED AS OF DATE:		20100617
DATE AS OF CHANGE:		20100617

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:			0802

	BUSINESS ADDRESS:	
		STREET 1:		PO BOX 999
		STREET 2:		260 LAKE RD
		CITY:			DAYVILLE
		STATE:			CT
		ZIP:			06241
		BUSINESS PHONE:		8607792800

	MAIL ADDRESS:	
		STREET 1:		PO BOX 999
		STREET 2:		260 LAKE RD
		CITY:			DAYVILLE
		STATE:			CT
		ZIP:			06241

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			FUNK MICHAEL S
		CENTRAL INDEX KEY:			0001240663

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-15723
		FILM NUMBER:		10904563

	MAIL ADDRESS:	
		STREET 1:		260 LAKE ROAD
		CITY:			DAYVILLE
		STATE:			CT
		ZIP:			06241
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>doc4_422.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2008-07-31</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001240663</rptOwnerCik>
            <rptOwnerName>FUNK MICHAEL S</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>313 IRON HORSE WAY</rptOwnerStreet1>
            <rptOwnerStreet2></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>2008-07-31</value>
                <footnoteId id="F2"/>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>F</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>1788</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>19.22</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>60369</value>
                    <footnoteId id="F3"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1504</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See footnote</value>
                    <footnoteId id="F1"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Includes 1,504 shares of common stock allocated to Mr. Funk under the United Natural Foods, Inc. Employee Stock Ownership Plan as of June 14, 2010.</footnote>
        <footnote id="F2">This report is being filed solely to report shares withheld to satisfy certain tax obligations in connection with the July 31, 2008 restricted stock award vesting for Mr. Funk, which were inadvertently omitted from filing.</footnote>
        <footnote id="F3">The ending shares beneficially owned are reported as of June 14, 2010.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Lisa N'Chonon, Power-of-Attorney, in fact</signatureName>
        <signatureDate>2010-06-17</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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