Several years ago, I was unsuccessfully searching for a study that evaluates the efficacy of many different interventions in the context of addictions. However, I did find a cognitive behavioral therapy (Copeland et al. 2001) that included a mindfulness technique called urge surfing and it was compared to other CBT interventions in cannabis use disorders. A definition follows from Marlatt (2002):
Other clients have described the successful use of "urge surfing" as a
mindfulness technique (Marlatt, 1985, 1994). Clients are taught to
visualize the urge as an ocean wave that begins as a small wavelet and
gradually builds up to a large cresting wave. As the urge wave grows
in strength, the client's goal is to surf the urge by allowing it to
pass without being "wiped out" by giving into it. I tell clients that
urges are often conditioned responses triggered by cues and high-risk
situations. Like a wave, the conditioned response grows in intensity
until it reaches a peak level of craving. Giving in to the urge when
it peaks only serves to further reinforce the addictive behavior. Not
acting on the urge, on the other hand, weakens the addictive
conditioning and strengthens acceptance and self-efficacy. Like any
skill, learning how to "urge surf" takes practice and improves over
time as the client attains greater balance on the mindfulness
surfboard.
Copeland et al. mention the use of urge surfing in their program:
The second session discussed urge management strategies such as‘‘urge
surfing’’ and nonreinforcement.
and reported
significantly better treatment outcomes than those receiving
notreatment. They were more likely to report abstinence during the
follow-up period, were significantly less concerned about their
control over cannabis use (as measuredby the SDS), and were more
likely to have significantly fewer cannabis-related problems than
those in the delayed treatment control group. Further, those receiving
six sessions of treatment significantly reduced their level of
cannabis consumption. These outcomes were unaffected by the therapist
delivering the intervention, but were affected by treatment
compliance.
Note that the study included a lot of other lessons. Regarding how often it should be done: The subjects were advised to use this technique whenever the urge appeared.
More info about urge surfing can be found in the freely accessible book Cognitive behavior therapy: Applying empirically supported techniques in your practice (2003) in Chapter 67.
Regarding the question about lifestyle factors, there have been countless studies (some cited in McGonigal's book) that indicate a positive effect of cardiovascular exercise, sufficient sleep, low-glycemic diets on self-regulation and so I will not cite them here.
Sources
Copeland, J., Swift, W., Roffman, R., & Stephens, R. (2001). A randomized controlled trial of brief cognitive–behavioral interventions for cannabis use disorder. Journal of substance abuse treatment, 21(2), 55-64. doi:10.1016/S0740-5472(01)00179-9
Marlatt, G. A. (2002). Buddhist philosophy and the treatment of addictive behavior. Cognitive and Behavioral Practice, 9(1), 44–50. doi:10.1016/s1077-7229(02)80039-6
Lloyd, A. (2003). Urge Surfing. In W. O'Donohue, J. E. Fisher & S. C. Hayes (Eds.), Cognitive behavior therapy: Applying empirically supported techniques in your practice (pp. 451-455). New York: John Wiley & Sons Inc.