Shorten datastore_v3.Next calls in Google App Engine when selecting objects (java), maybe?

I am trying to optimize code that reads objects from a Google data store. Using Java and JDO, here is my code:

List<Article> articles = (List<Article>) query.execute(articleId);
List<Article> detatchedArticles = (List<Article>) pm.detachCopyAll(articles);

When I look at the appstats logs, this results in:

datastore_v3.RunQuery   11ms (195ms api)
datastore_v3.Next   15ms (183ms api)
datastore_v3.Next   11ms (183ms api)
datastore_v3.Next   4ms (183ms api)

So my question is: can I somehow configure (JDO settings, other settings) how many objects are retrieved from the data store in datastore_v2.Next?

I am trying to win a few megabytes of API. Or, a lot, if what I want is possible.