EXHIBIT 31.1
                                CEO Certification

               CERTIFICATION PURSUANT TO RULE 13a-14(a)/15d-14(a)

I, Bradley T. MacDonald, certify that:

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

2.    Based on my knowledge,  this report 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-15(e) and 15d-15(e)) for
      the registrant and have:

      a)    Designed such  disclosure  controls and  procedures,  or caused such
            disclosure  controls  and  procedures  to be  designed  under  our (
            supervision,  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 in 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
            fiscal  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 my most recent  evaluation of internal control
      over  financial  reporting,  to the  registrant's  auditors  and the audit
      committee of the  registrant's  board of directors (or persons  performing
      the equivalent functions):

      a)    All significant  deficiencies and material  weaknesses in the design
            or operation of internal  control over  financial  reporting ( which
            are reasonably  likely to adversely affect the registrant's  ability
            to record, process, summarize and report financial information; 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.

Date: May 15, 2006


/s/ Bradley T. MacDonald
--------------------------------------------------
Bradley T. MacDonald
Chairman Of the Board and Chief Executive Officer


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