I dare say 是主句,后边是宾语从句 I deserved a good meal是宾语从句的主干 after.losing the twenty pounds .是状语起修饰作用的,I gained from too many trips to Manhattan restaurants last year是定语从句 修饰the twenty pounds .
I dare say 后面接的是宾语从句(I deserved a good meal after losing the twenty pounds) Twenty pounds 后面接的是定语从句,也就是说后面一句(I gained from too many Manhattan restaurants last year)是形容twenty pounds的。