-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
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<SEC-DOCUMENT>0001420506-10-000067.txt : 20100617
<SEC-HEADER>0001420506-10-000067.hdr.sgml : 20100617
<ACCEPTANCE-DATETIME>20100617213310
ACCESSION NUMBER:		0001420506-10-000067
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20100615
FILED AS OF DATE:		20100617
DATE AS OF CHANGE:		20100617

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Luttecke Kurt
		CENTRAL INDEX KEY:			0001465456

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-15723
		FILM NUMBER:		10904556

	MAIL ADDRESS:	
		STREET 1:		15965 EAST 32ND AVENUE
		CITY:			AURORA
		STATE:			CO
		ZIP:			80011

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
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>doc4_416.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2010-06-15</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001465456</rptOwnerCik>
            <rptOwnerName>Luttecke Kurt</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>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Western Region President</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2010-06-15</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>826</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>32.5314</value>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>3473</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>346</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 304 shares of common stock allocated to Mr. Luttecke under the United Natural Foods, Inc. Employee Stock Ownership Plan and 42 shares of common stock allocated to Mr. Luttecke under the United Natural Foods, Inc. 401(k) Plan's UNFI Stock Fund as of June 15, 2010.</footnote>
        <footnote id="F2">The transaction price listed is a weighted average.  Actual sale prices for these dispositions ranged from $32.5300 to $32.5363.</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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