How to delete Backbone model from localStorage collection - backbone.js

Question

I have created some models all saved in local storage collection. My challenge is how to delete a model fom the collection in local storage using one of the model attributes value. Below is extract of my code:
var Food = Backbone.Model.extend({
defaults: {
title: '',
calories: 0,
date: '',
history: false
}
});
var Foods = Backbone.Collection.extend({
model: Food,
localStorage: new Backbone.LocalStorage('Health-Tracker')
});
my_foods = new Foods({});
var ls = new Backbone.LocalStorage('Health-Tracker');
var res = ls.findAll();
var n = res.length;
var i, id;
for (i = 0; i < n; i++) {
food = res[i];
id = food['id'];
title = food['title'];
calories = food['calories'];
date = food['date'];
history = food['history'];
//I am stuck here
if (history) {
ls.remove(food); // Not working
// I have also tried this
ls.remove(id); // not working
}
}
Note that history is set to true successfully for some models in other section of the bigger codes. Above is only where I need to take action if history value is true. And it is bad code for now.
Any assistance is appreciated

Answer 1

Note that this app does not use server to store/retrieve data. All models are stored in the local storage. It is a very long process to use findAll() and remove() as I used above to delete from the localstorage. The following was added to delete models from the local storage:
my_foods.fetch();
my_foods.models.forEach(function(food){
day = food.get('day');
new_day = get_new_day();// this function isn't included above
if (new_day > day) {
food.destroy();
}
});