bang for your buck
下記の文のbecause 以下の意味がわからないので、教えていただけませんか。
よろしくお願いします。
"Most of my focus has been on diet, because the bang for your buck for changing your diet is really profound," Mozaffarian noted.
--補足--
【前後の文】
At the Harvard School of Public Health, Dr. Dariush Mozaffarian focuses on the connection between diet and chronic diseases.
"Most of my focus has been on diet, because the bang for your buck for changing your diet is really profound," Mozaffarian noted.
And Dr. Mozafarrian believes that just as growing numbers of Americans have quit their smoking habits, they can beat the obesity trap, and avoid the cancers and other diseases that result.
【出展】
VOA：http://www.voanews.com/english/news/health/Report-Obesity-Related-Cancers-Rising-136871703.html
お礼
ありがとうございます！！！！かなり助かりました☆