Assuming a person is in ketosis, eating clean, exercising, sleeping enough, and otherwise taking good care of herself, is there a limit to how fast it's safe to lose fat?
I'm interested in a general answer, but it might help to know a little about me. I'm a 32-year-old female who is about 70 pounds overweight. I've noticed that when I eat very clean (all real food, less than 50g carbs a day, 90-95% on plan), the scale drops .5 or 1 pound a day. For me, this has amounted to about 4 pounds a week. (The scale always holds steady after a cheat meal.) I eat whenever I get hungry and am not doing IF at this point.
Granted, I've only been doing this a few weeks. But my weight loss appears to be speeding up as my habits get better. My sense from reading Good Calories, Bad Calories is that my body will self-regulate, using up fatty acids as freely as they're available. I just wonder if there's a point where I would want to purposely slow down my rate of fat loss for some reason.
Well, I'd first have to say that there's a lot of people who wish they had your "problem."
Actually, it's not a problem at all and is quite normal for someone in the first couple of weeks that's got 70 pounds to lose. Assuming your normal weight is 130, then 70 pounds is quite a huge percentage of your total (I'm just guessing, of course).
The other thing is that if you've only been at this a few weeks (8-12 pounds lost?) then probably only about a half of that is fat, if that. The rest is water, assuming you're eating plenty of protein so as to preserve lean mass. Once you reduce the carbs so that your body has to begin depleting stored glycogen, water comes along with it. Off the top of my head, for every gram of stored glycogen in your system 1.5 – 2 grams of water is required to keep it there. When you use it, the water comes off too, and this is why low-carb dieters always get an initial burst of loss.
And now you say that it may be accelerating. I'd bet that's just temporary and is probably a function of your changing appetite. As you lose weight, you require less energy and as you become a fat burner, you're more in tune with hunger, so are probably eating less energy without even realizing it. So, you'll end up with a push & pull, manifest in periods of slower loss and then faster loss as your body adjusts.
The bottom line is that as you come closer and closer to your goal, your fat loss will almost certainly slow. This will be an excellent time to incorporate intermittent fasting into your way of living. You'll hit plateaus that may take weeks to break through but with IF can get you through in a few days. On the other hand, you're young, so this may end up being quite quick and easy for you.
In the end, don't worry. Congratulate yourself on finally finding a sustainable life. And, enjoy the rapid fat loss for as long as you can. Finally, think of this: how rapidly to hibernating bears lose fat, and does anyone think that's a problem?