If the jaculate volume is less than 1 ml a work-up might be warranted. The normal volume in ejaculation is 1.5ml to 5ml. The first thing you should due if you are concerned is to have a semen analysis performed. If at that time the volume is determined to be low, than you must first determined that the specimen was obtained properly(48-72hrs abstinence) and retrograde ejaculation has been ruled out. Low volume may represent a rare decreased in androgen levels.
Another cause for low volumes involve obstruction of the ejaculatory ducts, Vas Deferens, or epididymus. These obstructed areas could be determined by radiologic studies (ultrasound of prostate,Vasography)
I don't think that your diet has anything to do with your low ejaculatory volumes. I do think that you need to start at the beginning a have a semen analysis. In response to your comment about equating volume with sexual health, I think if you are able to have an erection and experience climax than your sexual health is fine. However , if you are trying to have a child and you are having difficulty then a complete infertility evaluation needs to be done.
This information is provided for general medical educational purposes only. Please consult your physician for diagnostic and treatment options pertaining to your specific medical condition.
Sincerely,
HFHS M.D.-AK
*keyword: Ejaculate volume