Question

people in my opinoin should neither eat too often nor too mu

Answer 1

没什么大的错误,就是听起来有点怪怪的.改成下面这种表达就好了：

In my opinion,people should neither eat too often nor too much fast food.

当然,书面文字可以写成：

People,in my opinion,should neither eat too often nor too much fast food.