Cameron Dixon, 28, was twice the limit when he was seen riding unsteadily over the pavement before falling off his bike.
Staff alerted a policeman who was on a break inside the Admiral Retail Park McDonald’s in Eastbourne.
Dixon, of Whitley Road, Eastbourne, admitted driving over the limit.
He was disqualified from driving for 17 months and ordered to pay a £346 fine, £85 costs, and a £138 surcharge.