diff --git a/app/views/ingredients/_filters.html.erb b/app/views/ingredients/_filters.html.erb
index 7fa6e12..2944013 100644
--- a/app/views/ingredients/_filters.html.erb
+++ b/app/views/ingredients/_filters.html.erb
@@ -13,6 +13,11 @@
           visibility_options(session[:filters][:visibility]),
           :onchange => '$("#filters_form").submit(); return false;' %>
       </td>
+      <td>
+        <%= text_field_tag 'filters[nutrients]', session[:filters][:nutrients],
+          placeholder: 'conditional expression including nutrients', size: 40,
+          :onblur => '$("#filters_form").submit(); return false;' %>
+      </td>
       <td>
         <%= link_to l(:button_apply), '#', :class => "icon icon-checked",
           :onclick => '$("#filters_form").submit(); return false;' %>
diff --git a/lib/body_tracking/filter.rb b/lib/body_tracking/filter.rb
new file mode 100644
index 0000000..e69de29