Mongoose insert empty Object in array

I am trying to update collection using mongoose with NodeJS .when I log data to NodeJs console it prints the data but not data is not being pushed in collection. But when i run the same query on mongodb console then it works Here's the code

portoflio is array of objects

portfolio_user={ 'title' : 'this is the sample link', 'type" : 'link', 'url" : 'www.emumba.com' }

var user_id=req.user._id;
console.log(user_id);
var portfolio_user=req.body;
console.log(portfolio_user)
 User.update({_id:user_id},{
    $push:{
        "portfolio":portfolio_user
    }
},
function(err, user){
     if (err) {
        console.log(err);
    } else {
        console.log(user);
        res.jsonp(user);
    }
});

Note: I have also tried findOneAndUpdate and findById but they still dont work

via shaheer khan