我如何优化这个Linq查询来删除不必要的SELECT Count(*)

我有三个表，实体，期间和结果。Entity和Period之间是1:1的映射关系，Period和Result之间是1:Many的映射关系。

这是linq查询:

int id = 100;
DateTime start = DateTime.Now;
from p in db.Periods
where p.Entity.ObjectId == id && p.Start == start
select new { Period = p, Results = p.Results })

生成的SQL的相关部分:

SELECT [t0].[EntityId], [t2].[PeriodId], [t2].[Value], (
    SELECT COUNT(*)
    FROM [dbo].[Result] AS [t3]
    WHERE [t3].[PeriodId] = [t0].[Id]
    ) AS [value2]
FROM [dbo].[Period] AS [t0]
INNER JOIN [dbo].[Entity] AS [t1] ON [t1].[Id] = [t0].[EntityId]
LEFT OUTER JOIN [dbo].[Result] AS [t2] ON [t2].[PeriodId] = [t0].[Id]
WHERE ([t1].[ObjectId] = 100) AND ([t0].[Start] = '2010-02-01 00:00:00')

SELECT Count(*)来自哪里，我如何摆脱它?我不需要每个"Period"的"Results"计数，这会使查询速度降低一个数量级。