MainActivity-toolbar_menu.java

@Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.main_menu, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()) {
            case R.id.meal_list_item:
                Intent intent = new Intent(this, MealListActivity.class);
                startActivity(intent);
                return true;

            default:
                return super.onOptionsItemSelected(item);

        }
    }