I'm just starting also and I've never had a need to lose weight before, so I was a little bit confused on how to pick a number. I was told by a Dr. & nutritionist to start with a small obtainable goal. So although I'd like to lose 45 lbs by tomorrow, it would be much more reasonable for me to say I want to lose 5-10 lbs in the next 30 days (I chose 10). Since I'll be exercising and eating better the belief is the weight will initially come off fairly quickly and then taper down over time. After 30 days you re-evaluate if the goal was reasonable and achieved, reasonable and not achieved(Exercise and food tracking can give insight) or unreasonable and not achieved based on changes in diet and the amount of physical activity. Then set a new goal. I'm giving it a try, I'm hoping it works. Best of luck to you!