jillianfan-- At your weight you probably could eat 1200 calories/day and be okay, but I think you need to not worry about trying to speed up the weight loss. Typically it is safe to average a weight loss of 1/2 to 1% of your body weight/week. At 149, you probably won't average more than 3/4-1.5 pounds per week!

As for the shows where people lose the weight quickly, what happens after the event?? Frequently when people lose weight for a specific event, they gain it back again afterward! Partly because they aren't planning for maintenance while losing, and they aren't engaging in behaviors that are sustainable for the long term.

So, think about your long term goals. Do you want to lose the weight and KEEP it off? Or do you want to lose it quickly and then gain it back again because you weren't focused on keeping it off?

It actually sounds like you're doing pretty well -- 1400 calories a day and regular exercise sounds safe. It's also effective! You're losing a pound a week!!

I do a lot of biking, running and swimming in my training for triathlons so I end up with about 2-3 hours of activity some days. I'm only trying for a slightly bigger loss per week because I have group training beginning in Feb and the more I lose before then the easier it will be.

Let us know how it goes with what you decide!

A pound a week sounds very good to me, especially at your current weight - don't knock it! Some women settle into a slower rate than that.

I don't believe it's physically possible to run a calorie deficit over a prolonged period and not lose weight. By a prolonged period I mean months; not a week or two. If you run a calorie deficit for long enough, you'll lose weight.

Having said that, there are healthy and unhealthy ways to lose weightl sustainable and unsustainable. Starvation mode can happen; your metabolism can slow down to conserve energy and make you feel tired and horrible. It won't stop you from losing weight in the long run, but it will make you feel like crap and make your body eager to pack the weight right back on as soon as you are no longer running the deficit. That's why you've heard recommendations on this thread of not going below a certain amount of calories.

What that amount is, as others have pointed out, is going to vary from body to body. You can use calculators like the one at fitday.com to estimate your base metabolic rate and get a sense of what you are burning in your workouts, and then adjust yourself to a healthy calorie deficit of maybe 500-700 calories per day (which will amount to about 1-1.5 pounds per week of weight loss).

But your body may vary, and the only way to find out is to do the science experiment. You can try one calorie deficit for a month or two, see how the results are, and then adjust for the next month or two. This is a long-term prospect for a long-term process. It might even mean slowing down your weight loss for a month or two as you explore different amounts of calorie deficit. But if you want to know the optimum level for yourself, you'll have to run the experiment on your own body.

Today I'm beginning to believe in caloriecycling... I've been really good, eating about 1600 calories per day (theoretical 500 deficit for me), for a week without ANY change on the scale. Then in a moment of madness I ate about 2500 calories yesterday, which is definitely more than I burn a day, and hey presto the scale has finally moved.