ANOTHER DREADED CARB POST.....for Runners!

At 38, I trained for a half marathon, and made sure that my diet was like 55-60% carbs (brown, not very much white). I lost weight like crazy, and then, in taper week, when my running tapered off and my carb eating went up, I lost an additional 3 pounds. More carbs = more weight loss for me. But I'm a weirdo like that.

Sounds like hormonal issues around. Maybe a higher sensibility by the adipocytes to the insulin low leverls, since you were training a lot without providing enough. Not an expert though.
I read lately an article explainning how an non-adapted diet could cause gain weight. I'll try to find it

EDIT : ok explanations :
Every time you eat carbs, (and in a measure, proteins), the body produces insulin. The insulin is being produced when the glycemic level changes. The insulin has two roles : anti-catabolism on the muscles, but anabolism on the adipocytes (fat cells) if the meal you just took was too high in calories.

- First part of the diet -
In order to loose weight, you need to fast. By fasting, glycemic levels remain stable, the pancreas is not used, the insulin doesn't go right into the blood. Because the insulin prevents fat from being burnt, reducing it helps the fat burning. By extension, you loose weight.

- The diet slows down -
Quickly,the first defensive mechanism comes, when the insulin levels lower, the sensibility by the fat cell for the insulin increases, that means you'll need to eat less if you want to maintain the fat burn.

- Then comes the stagnation-
If you preserve that state, fat cell will be so sensitive to insulin, that you'll hit that famous plateau - in other words, you won't loose any more weight, even if you eat less (or even reducing the carbs to 0), the proteins will trigger insulin production, insulin that would be quickly taken by the adipocytes (extra sensibility to it).

The famous plateau is that
At that state, eating less is useless, the fight becomes pointless.

Fortunately, when you eat less, three hormones come into play : Adrenalin, Noradrenalin, and Growth hormone.
These 3 are called "lipolytic hormones", and help the fat burn.

- And then comes the weight gain -
After long diets, thyroids hormones and leptin ones will crash, making the 3 hormones useless.
When you hit that plateau, loosing weight turns to be a real torture, slow and painful process. In fact the thyroid will shrink, and... YOU GAIN WEIGHT Even if the calories intakes are very low.

Thyroid being the key to the metabolism regulation, by making if weaker via diets, the weight gain turns to be unavoidable

You could try playing around with older fashioned grains legacy grains and pseudo-cereals (like quinoa). Sometime people's bodies react better to the lesser tampered with grains. Also if you are eating prepared rice/bread be mindful of sodium content. I am also a runner (12-18mi/week) and was never sensitive to sodium before i started working my muscles. Now that i run am running and cross training i can blow up 7-8lbs in 48hours with water weight if i eat more than 2500mg/day >.<

Also you could just be putting on muscle, if you body did not have enough fuel before and that 200Kcal is what it took to start building, then you are better off in the long run

I have increased my miles as well over the last month and my weight has increased! Very frustrating.

I dont think you are eating enough to support your activity at all. 20-25 miles a week and only 1400 cals a day?

I dont know how much you weigh but your cals seem very low. If you're going to be doing such strenuous activity then your calorie deficit from food needs to be lower.