Laravel Eloquent with Eager Loading eat memory

why this query is increase my Memory after Each loop? how can i Free that result?

public function getUser($startId, $endId){
$query = User::where('action','register')
                    ->whereBetween('id', [$startId, $endId])
                    ->whereNotNull('user_id')
                    ->with(array('user.jPayUser' => function($query){
                        $query->select('id','gender','generation');
                    }));

return $query->get(array('users.*'));
}

User table have about 20k Record.

$chunk = 1000;

for($i = 1; $i <= $count; $i += $chunk)
    {
        $userLists = $this->getUser($i, $i + $chunk);

        echo memory_get_usage();//It increase
    }

I was research and put DB::disableQueryLogs() but still eat memory

via user3809000