Hello, Thanks for using healthcaremagic. Young man, there is no need to stop masturbation habit as it is not harmful but it is natural.It is not going to cause and loss of concentration.I guess your concentration problem is just due to anxiety regarding masturbation. Note carefully whatever I am going to explain. Normally after age of 13 or 14 almost all boys enters in to phase of adolescence. In this phase testosterone secretion increased, beard mustache growth started, hair around genitalia started growing and adolescent boys attracts towards opposite sex and gradually learn masturbation(excitation and ejaculation by sexual thoughts though rubbing penis by own hands). With this semen production (majority by prostate and sperms by testis) started. As semen produce daily and it accumulate in prostate.Its production generally cost 1-2 % part of your daily calorie intake,so missing 1 % from your whole day food has nothing to do with your concentration.It is just perception of yours. Your habit of masturbation is not bad at all until it s compulsion. As most of the young man like you do masturbation(almost 95%). Frequency of masturbation varied from once in a day to once in a week individually.You should not suppress your desire.If you completely stop doing this, after a storage capacity level exceeds in prostate, semen has to come out in night during sleep or during toilet. So just understand this physiology of body . I think don t suppress your sexual tension. Just continue your masturbation whenever you desire, it will automatically release your built up semen until you married. For your concentration problem, you need to have one sitting with psychiatrist to rule out any other cause.Some multivitamin might help. Hope I have answered your query.late me know if still any info needed. Regards, Dr. Chintan Solanki