1.  Not drinking at least 8 cups of water a day.  Water is a metabolism booster!

2.  Eating too much meat and not enough fiber--constipated.  Aim for 3 oz. of chicken or 5 oz. of fish, then fill the rest of the 3/4ths of your plate with fiber-rich veggies, beans, or nuts, depending on which cycle you're on.  (I had no problems, being vegetarian, I replaced meat with beans or lentils.)

3.  Not consuming enough calories, your body is going into starvation mode.  Keep a mental estimation of calories consumed per day and aim for at least 1200.

4.  Consuming too many calories, you're not creating a big enough calorie deficit.  Try not to go over 1500 calories per day when dieting.

5.  Exercising too hard and not eating enough.  You're really going into starvation mode!

6.  Not exercising enough.  This is something I struggle with.  I'm trying to get 30-60 mins of moderate intensity, 5 days a week...

7.  You're too stressed out.  Your body creates cortisol, a hormone that likes to create and hold on to belly fat.  Try yoga, taking deep breaths, making a to-do list, hot bath, nature walk, etc.

8.  Not getting enough sleep.  I notice when I've had a bad night's sleep, my thighs look bigger and my belly, bloated.  Not sure if this is scientific, but it's something I've noticed with me.  As soon as I start to get more rested sleep, 7-8 hours, the weight (possibly water weight?) melts away.

9.  You may have low thyroid levels.  Get a blood test.  Low thyroid = slow metabolism.  (I have borderline low thyroid for the past 2 years, but it hasn't affected me too much, I have no real symptoms, knock on wood!)

10.  You are overworking your adrenal glands by drinking too much caffeine.  Adrenal overload can cause fatigue, slowed metabolism, and weight gain.  A couple years ago, I relied on a few cups of coffee for energy.  My adrenals were so overworked that the caffiene didn't work anymore, I actually got MORE tired drinking coffee.  Now I just drink 1-2 cups of green tea a day.

11.  If you are a woman, PMS can make you gain up to 5 pounds of water weight!

12.  You're sneaking sugary snacks.  Excess calories, plus sugar in general, makes you gain weight.  I cut out sugar around January of this year, and my weight slooowly started decreasing.  The 17DD I started in the spring of this year made me lose even more, my point being, just cutting out sugar and not dieting makes you lose weight.

13.  Some prescription drugs can cause you to gain weight, or make it hard to lose weight.  I'm not sure which ones, I think a blood pressure med, possibly birth control pills, etc.  Every time I start birth control pills, I gain weight because they make me feel hungry for a few months, then it levels out.   

14.  Maybe you're really working your muscles and are gaining a lot of muscle.  Muscle weighs more than fat, so in this case, go by how you look, not the number on the scale.

15.  If you suffer from a food allergy, like wheat, you could be holding on to weight.  I have a gluten intolerance, which caused me to bloat and retain more water weight.  When I elimated gluten, the bloat and water weight went away.

16.  You could be taking in too much salt...major culprit in water retention.  Raw meat is packed with tons of sodium that may or may not be on the label.  As Dr. Mike suggests, learn to use herbs and spices as flavoring.  Me, I can't live without Morton Lite Salt.  It only has 290 mg sodium and has the water-shedding mineral, potassium, 350 mg! (per 1/4 teaspoon)

17.  It could be that you're not letting enough time pass, and you are impatiently standing on the scale too soon.  Weight loss is not instantaneous.  When I'm wondering why I'm not losing weight, my husband reminds me that it takes time for your body to react and process the weight loss, takes time for your body to rid the excess weight through whatever process it goes through.  And sure enough, a couple days later, my weight is lower!