Distributions sensitive to the underlying event are studied in events containing one or more charged particles. Jets are reconstructed using the anti-kt algorithm with radius parameter R varying between 0.2 and 1.0. Distributions of the charged-particle multiplicity, the scalar sum of the transverse momentum of charged particles, and the average charged-particle pT are measured as functions of pjet⊥ in regions transverse to and opposite the leading jet for 4GeV<pjet⊥<100GeV. In addition, the R-dependence of the mean values of these observables is studied.