This has been my experience with low carb - I can eat a high protein, high fat meal that will stuff me and be ~1000 calories, but I'll be satisfied for at least the rest of the day if not most of the next. Even if it's just calories in / calories out it's a clear win over my normal diet.

Of course people used to think this long fasting is really bad (my parents, for example), but it seems like new research says it's fine, if not healthy for weight loss.