Can't Be Starvation Mode, So What Then?

Hi there, need help. I've lost 20 pounds and came to a screeching halt, no loss in over a week. In fact I think I gained a couple back. I don't think I am on starvation mode, I always reach my target of 1500 cals/day, really.

I have been having awful headaches lately, and started to drink water like a maniac and they stopped.

Still a litlle constipated but getting better.

Any ideas about why I stoped losing weight?

First off, I like your Superman image. :-)

Are you staying within your sodium limits? Have you been tracking your fiber at all?

The constipation might be due to not getting enough fiber. It's hard to say what might be the problem without seeing your dieary but maybe take a look at your carbs,fats and salt. I know eating a lot of carbs stalls me. If I eat to much bread I can forget any weight loss. One week of no weight loss is not really a problem. A few weeks might be a stall. It also depends on how much weight you have to lose. If you have to lose a little weight it might take longer than needing to lose a lot of weight.
Good Luck. You can do it.

If you've lost 20 lbs have you re evaluated your calorie needs? Are you working out? Are you eating your exercise calories? Are you watching sodium? Being too hungry and not getting enough calories could be linked to headaches. This past weekend I KNOW I didn't eat enough but I was so worried about going over I really watched it. As a result on Sunday morning I woke up with a headache. In fact, this morning I did too. Headaches can also be caused by dehydration but I saw in your original post you drank water and they went away.

I say look at your calorie goals and see if they changed as you dropped the 20lbs. I also suggest you watch your sodium. If you are eating a lot of processed foods that are packed in sodium, you may actually GAIN weight. Case in point, I gained 3lbs from one day to the next after a day at Disneyland and planned bad eating. I lost that weight and another 2.2lbs. Sometimes you have to shock your body into moving again. As another poster here said, try setting your calories to maintenance to see if that works. You will be eating more food, but that may help. Before doing that though you should reevaluate your base calories.

Do you use a HRM to count your calories?
I'm in my 60s (alot OLDER than most here) and when I started walking I was burning close to the calories on MFP. I walk outside with lots of hills. Within a month my same walk at a faster pace with the same hills was burning 100 fewer calories for a two mile route.
The good news is that walking (and slow jogging) can get you fit fast. The bad news is that you may now be fit and need to do more to get the same burn.

Headaches and constipation can both be symptoms of mild to moderate dehydration. Make sure you're getting enough water every day. Upping water intake helps some people with a plateau too.