Plateau?
 

I am puzzled as to why the scale has not budged for three weeks. I have been faithful in logging, and have had a calorie deficit of between 500 and 800 each day (protein about 27%, carbs below 15%); have been exercising 4-6 hours per week; drinking water - but staying stubbornly stuck at 165 lbs. The same regimen was producing 1-2 lbs of loss per week. The only difference is that for the last 4 weeks I have been exercising early in the morning instead of mid-morning. Can sleep changes really make that big a difference? And if so, will my body get used to this and start losing again?

Sometimes it just happens!
 

Here's a link to the search I did for all plateau threads...some of this may help: FitDay Discussion Boards - Search Results

The important thing is to hang in there, change things up a bit (type of exercise, pie chart ratios, etc.), and don't give up!

the crazy thing about plateaus is that they happen out of nowhere without logical or reason. Very easy to get discouraged, but DONT~ keep your eye on the goal or mini goal you've set for yourself. It happens to all of us at one point in our journeys... booo!

Try changing what you do for your workout this week, add a bit of weight training if you dont, different muscle groups. Surprise your body by eating a calorie amount that would be a maintenance level for a couple days and see if that helps.

Im with Cassie, keep your focus and it will move, just be patient! DONT GIVE UP KEEP SWIMMING!