翻译：令人惊讶的是（德克萨斯大学的心理学家提出来用于阻止女孩患上饮食紊乱症的）方法.


这是一个主从复合句.
主干是：What is surprising is the method.



主句主语为一个主语从句：What is surprising
其中引导词为what,并在从句中充当主语,从句谓语为系表结构：is surprising

主句谓语也是系表结构,其中系动词为is,而表语为the method,其后是一个定语从句（修饰表语the method)：psychologists at the University of Texas have come up with to keep girls from developing eating disorders

该定语从句中,主语为psychologists,其后为介词短语做后置定语（修饰psychologists)；
have come up with为谓语；
宾语即为关系代词which/that（代指先行词the method）,因为关系代词做宾语,所以在句中被省略；
不定式短语to keep girls from devloping eating disorders也是后置定语,修饰被省略的宾语.