1．This trend, which was started by the medical community (医学界) as a method of fighting heart disease, has had some unintended side effects such as overweight and heart disease—the very thing the medical community was trying to fight.
[分析] which was started by the medical community as a method of fighting heart disease是非限制性定语从句，破折号后面的 the very thing the medical community was trying to fight 是对overweight和heart_disease的补充说明。
[翻译] 作为医学界为了抵抗心脏病而发起的这股潮流，它也有一些难以预料的副作用，如过度肥胖和心脏病，而这正是医学界试图抵制的。
