Pilot study of a ketogenic diet in bipolar disorder: a process evaluation by P. Rigby, B, Needham, N, Grossi, H, Kamenska, I, H. Campbell, I, Meadowcroft, B, Creasy, F, Fisher, C, Bahuguna, P, Norrie, J, Thompson, G, C. Gibbs, M, Mitchell-Grigorjeva, M, McLellan, A, Moses, T, Burgess, K, Brown, R, J. Thrippleton, M, Campbell, H, J. Smith, D, A. Simpson, S