<DOCUMENT>
<TYPE>EX-32.1
<SEQUENCE>4
<FILENAME>v037843_ex32-1.txt
<TEXT>

EXHIBIT 32.1

CERTIFICATION PURSUANT TO
18 U.S.C. SECTION 1350,
AS ADOPTED PURSUANT TO
SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002



In connection with the Annual Report of Medifast, Inc. (the "Company") on Form
10-K for the year ended December 31, 2005 as filed with the Securities and
Exchange Commission on the date hereof (the "Report"), I Bradley T. MacDonald,
Chief Financial Officer of the Company, certify, pursuant to 18 U.S.C. Section
1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, to
the best of my knowledge, that:

(1)      The Report fully complies with the requirements of Section 13(a) or
         15(d) of the Securities Exchange Act of 1934, as amended; and

(2)      The information contained in the report fairly presents, in all
         material respects, the financial condition and results of the
         operations of the Company.



By: /s/ Bradley T. MacDonald
-------------------------------
        Bradley T. MacDonald
        Chief Executive Officer
        March 15, 2006


By: /s/ Michael S. McDevitt
-------------------------------
        Michael S. McDevitt
        Chief Financial Officer
        March 15, 2006










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