Is a motivational interviewing based lifestyle intervention for obese pregnant women across Europe implemented as planned? Process evaluation of the DALI study by Jelsma, JGM, Simmons, D, Gobat, N, Rollnick, S, Blumska, K, Jans, G, Galjaard, S, Desoye, G, Corcoy, R, Juarez, F, Kautzky-Willer, A, Harreiter, J, Van Assche, A, Devlieger, R, Timmerman, D, Hill, D, Damm, P, Mathiesen, ER, Wender-Ożegowska, E, Zawiejska, A, Lapolla, A, Dalfrà, MG, Del Prato, S, Bertolotto, A, Dunne, F, Jensen, DM, Andersen, L, Snoek, FJ, Van Poppel, MNM