If you are using MSTest, you may want to take a look at CollectionAssert.AreEqual.
Enumerable.SequenceEqual may be another useful API to use in an assertion.
In both cases you should prepare a list that holds the expected list in the expected order, and then compare that list to the result.
Here’s an example:
var studyFeeds = Feeds.GetStudyFeeds(2120, DateTime.Today.AddDays(-200), 20);
var expectedList = studyFeeds.OrderByDescending(x => x.Date);
Assert.IsTrue(expectedList.SequenceEqual(studyFeeds));