If you are near an academic library, you can try searching databases such as Academic Search, which gets 29 hits for the search: attention deficit and adult* and alternative*, 22 of them from scholarly/peer reviewed journals. Psycinfo, a highly technical and scholarly database, gets 64 hits for that same search. For more popular articles, you can search magazine databases such as Masterfile or Infotrac, or newspaper full text databases. Most public libraries allow even remote access to these, with a library card.
You can also search Pubmed, clicking on their "Limits" tab just to lower left of the search box, to choose Adults age group, and even "Links to free full text". Using these limits, I got 11 articles for the search: attention deficit and alternative, 7 for attention deficit and diet, and 10 for attention deficit and nutritional.
Even some highly respected publishers allow free search of their journals - just no free access to full text. For example, Science Direct, a VERY expensive full text database of Elsevier journals, is available at many academic libraries, but also allows anyone to see the titles, authors, and abstracts of most of their articles. The search: "attention deficit" and adult and alternative* gets 16 hits.
