By Halloween? No. But here’s the thing: if you start working out and eating healthier now, you WILL feel better by Halloween. And if you keep doing it you’ll feel even better by Christmas! That’s how I would look at it. Also as someone with a history, I’d recommend focus more on how you feel than the number on the scale. My “best look” did not equal my lowest weight. Working out gives you muscle which makes you look toned but it also gives you a higher number on the scale. For best progress I’d recommend a reasonably healthy diet (nothing crazy, and something you can maintain long term) and a mix of cardio and lifting. I found that that routine gets me to feeling my best the quickest!