Working Out + Consuming Less Calories = Weight Gain?

Question
For the last month I've been tracking my food intake and I've been averaging about 500 calories/day, while working out 3 to 5 times/week.  The food is mostly vegetables, fruits and lean protein with an average fat intake of 15% (with red wine 3x/week) The work outs include both cardio and light weight/resistance training.  

Twice, in the last few weeks, I've noticed a weight GAIN of 1.5lbs that lasted about 4 days - for no discernible reason.  Could any human metabolism be that dysfunctional?  I'm 39 years old, 5' tall and weigh 108 lbs.  I appreciate any insight you can offer.

Answer
You are eating WAY TOO FEW calories.  It is unhealthy as well as dangerous and a detriment to weight loss!!  Eating too few calories robs your body of needed fuel and essential nutrients for proper functioning!!  In addition you put your body into a "starvation" mode in which is starts to hang onto fat to use as fuel down the road.  This CAN cause weight gain.
My suggestion is to start eating healthier and start eating a more well-balanced diet WITH more calories.  You can check out www.mypyramid.gov to find out how many calories you SHOULD be eating every day for your gender, activity level, age, etc...
Kim Tessmer, RD LD
www.Nutrifocus.net

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