From addiction expert Dr. Mike Dow, author of "Diet Rehab" and host of TLC's "Freaky Eaters":

Many diets begin by limiting calories, fat, or carbohydrates.  But behavior - especially overeating - begins in the brain.  So your cravings, inability to stick to a diet, or making healthy choices on a daily basis may be rooted in low levels of serotonin. 

Serotonin is the brain chemical associated with feeling happy and peaceful.  It's also released when you eat sugar and processed carbohydrates (as opposed to the activating chemical dopamine which is released when you consume fat and caffeine).  When you eat foods high in sugar and processed carbohydrates on a consistent basis, this conditioned behavior causes food addiction in the brain.

My book, "Diet Rehab, " will help you balance your brain chemistry through serotonin booster foods and activities, so you can finally stop craving the foods that make you fat.  To find out if low serotonin may be the cause of your inability to rehab your diet, take this 10-question quiz:

Score the following:

0 - never

1 - rarely

2 - sometimes

3 - frequently

4 - always

1. I often crave sugar, carbohydrates, foods with a soothing texture, such as ice cream, or soothing temperatures, such as soup.
2. I often feel I don't get enough of one or more of the following: calm, serenity, peace, or quiet.
3. I question myself and wonder whether I'll be good enough to reach my goals.
4. I often feel lonely.
5. I prefer a job where there is not much pressure or where I can work alone without competition or demands.
6. I startle easily or am easily frightened.
7. I often get stuck in anxious thoughts.
8. When I have a physical symptom, I worry about what potentially life-threatening disease I might have.
9. I often have trouble falling asleep.
10. I often feel overwhelmed.

If you answered ALWAYS to TWO or more questions, low serotonin may be what's keeping you stuck in unhealthy choices. 

*This is an adapted version of Dr. Mike Dow's serotonin quiz. Click HERE for the full one.

Balancing your brain chemistry is the most important change if you want to improve your everyday choices that affect your health.  The balanced and sustainable levels of serotonin will give you the motivation to sustain lasing change in your life.  

Click HERE to read more about Dr. Mike Dow's 28-day "Diet Rehab" plan and how he helped one former plus-size model bring down her weight on " Nightline."