EXHIBIT 31.1

                                CEO CERTIFICATION

I, Bradley T. MacDonald, the registrant, Chairman of the Board and Chief
Executive Officer certify that:

1.    I have reviewed this quarterly report on Form 10-Q of Medifast, Inc.;

2.    Based on my knowledge, this 10-Q does not contain any untrue statement of
      a material fact or omit to state a material fact necessary to make the
      statements made, in light of the circumstances under which such statements
      were made, not misleading with respect to the period covered by this
      report;

3.    Based on my knowledge, the financial statements, and other financial
      information included in this report, fairly present in all material
      respects the financial condition, results of operations and cash flows of
      the registrant as of, and for the periods presented in this report;

4.    I am responsible for establishing and maintaining disclosure controls and
      procedures (as defined in Exchange Act Rules 13a-14 and 15d-14) for the
      registrant and have:

      a.    Designed such disclosure controls and procedures to ensure that
            material information relating to the registrant, including its
            consolidated subsidiaries, is made known to us by others within
            those entities, particularly during the period by which this report
            is being prepared;

      b.    Evaluated the effectiveness of the registrant's disclosure controls
            and procedures and presented in this report our conclusions about
            the effectiveness of the disclosure controls and procedures, as of
            the end of the period covered by this report based on such
            evaluation; and

      c.    Disclosed in this report any change in the registrant's internal
            control over financial reporting that occurred during the
            registrant's most recent fiscal quarter (the registrant's fourth
            quarter in the case of an annual report) that has materially
            affected, or is reasonably likely to materially affect, the
            registrant's internal control over financial reporting; and

5.    I have disclosed, based on our most recent evaluation, to the registrant's
      auditors and the audit committee of registrant's board of directors:

      a.    All significant deficiencies in the design or operation of internal
            controls which could adversely affect the registrant's ability to
            record, process, summarize and report financial data and have
            identified for the registrant's auditors any material weaknesses in
            internal controls; and

      b.    Any fraud, whether or not material, that involves management or
            other employees who have a significant role in the registrant's
            internal control over financial reporting.

May 10, 2005

/s/ Bradley T. MacDonald
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Bradley T. MacDonald
Chairman of the Board & Chief Executive Officer