-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 HQREilKwahKePLdQWw/OKABLNSh4EiJ3UsYLXZeb+2/qjhOX+K63KHbJKVX8eD/U
 0SdfSTmQNG/lLe+NAplkyQ==

<SEC-DOCUMENT>0001144204-06-021456.txt : 20060518
<SEC-HEADER>0001144204-06-021456.hdr.sgml : 20060518
<ACCEPTANCE-DATETIME>20060518160044
ACCESSION NUMBER:		0001144204-06-021456
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20060516
FILED AS OF DATE:		20060518
DATE AS OF CHANGE:		20060518

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			MEDIFAST INC
		CENTRAL INDEX KEY:			0000910329
		STANDARD INDUSTRIAL CLASSIFICATION:	MISCELLANEOUS FOOD PREPARATIONS & KINDRED PRODUCTS [2090]
		IRS NUMBER:				133714405
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		11445 CRONHILL DRIVE
		CITY:			OWINGS MILLS
		STATE:			MD
		ZIP:			21117
		BUSINESS PHONE:		7327640619

	MAIL ADDRESS:	
		STREET 1:		11445 CRONHILL DRIVE
		CITY:			OWINGS MILLS
		STATE:			MD
		ZIP:			21117

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	HEALTHRITE INC
		DATE OF NAME CHANGE:	19951120

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	XX
		DATE OF NAME CHANGE:	19950619

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	00
		DATE OF NAME CHANGE:	19950619

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			MACDONALD MARGARET
		CENTRAL INDEX KEY:			0001224955

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-31573
		FILM NUMBER:		06852194

	BUSINESS ADDRESS:	
		STREET 1:		11445 CRONHILL DR
		CITY:			OWINGS MILLS
		STATE:			MD
		ZIP:			21117

	MAIL ADDRESS:	
		STREET 1:		9332 OWINGS CHOICE CT
		CITY:			OWINGS MILLS
		STATE:			MD
		ZIP:			21117
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>v043739_ex.xml
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2006-05-16</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000910329</issuerCik>
        <issuerName>MEDIFAST INC</issuerName>
        <issuerTradingSymbol>MED</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001224955</rptOwnerCik>
            <rptOwnerName>MACDONALD MARGARET</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O MEDIFAST INC.</rptOwnerStreet1>
            <rptOwnerStreet2>11445 CRONHILL DR</rptOwnerStreet2>
            <rptOwnerCity>OWINGS MILLS</rptOwnerCity>
            <rptOwnerState>MD</rptOwnerState>
            <rptOwnerZipCode>21117</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>N/A</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2006-05-16</value>
            </transactionDate>
            <deemedExecutionDate>
                <value>2006-05-16</value>
            </deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>50000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>15.19</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>137605</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <remarks>1. N/A</remarks>

    <ownerSignature>
        <signatureName>/s/ Margaret E. MacDonald</signatureName>
        <signatureDate>2006-05-18</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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