Addiction expert Dr. Mike Dow, author of "Diet Rehab," host of TLC's "Freaky Eaters" and co-host of VH1's "Couples Therapy," offers these five steps for getting your diet back on track.

Watch how Dr. Mike Dow's 28-day "Diet Rehab" plan helped one former plus-size model bring down her weight:

Step 1: Ask yourself: What am I truly missing in my life? The answer to this question will help you understand what your brain is really hungry for and if you're low on serotonin, dopamine, or both. If you need more serenity, stability, or happiness in your relationship or job, you may be low on serotonin. If you need less boredom, more adventure, or to feel like you're living and not just existing, it's dopamine you need. Sugar and processed carbohydrates provide short-term boosts of serotonin, and high fat foods provide short-term boosts of dopamine. But using soda, pizza, and fries to try and feel better right now will prevent you from getting the serotonin and dopamine you're craving in the long-run.

Take the full serotonin and dopamine quizzes HERE: http://www.drmikedow.com/diet-rehab/serotonin-quiz

Step 2: When you're craving an unhealthy food today, try adding a serotonin or dopamine booster activity. The serenity of a 10 minute walk in the middle of a busy work day will give you a sustainable boost of serotonin you would have gotten from that candy bar or soda. And the vitality you'll get from reconnecting with an old friend will give you the same boost of dopamine you would have gotten from those potato chips or fries.

Other serotonin booster activities could include cuddling with your significant other or a pet, joining a support group, listening to classical music, doing errands on foot, or looking into someone's eyes when you're talking to them. Dopamine booster activities include asking a special someone on a date, cooking something you've never made before, getting eight hours of sleep tonight, attending a bootcamp-style fitness class, or hitting the playground with the kids. Come up with your own booster activities to start to change your brain chemistry here and now.

Step 3: Eat more food to lose more weight! Now that you realize what you're adding to your life is more important than what you're taking away, eat more booster foods today. Booster foods are healthy foods that give your brain a slow, steady release of serotonin or dopamine while staying in your stomach about twice as long as those unhealthy pitfall foods. You'll feel fuller, longer. This makes it easier to choose even more booster foods throughout the day.

Serotonin booster foods like high fiber cereal, whole fruit, or high fiber pasta and veggies in marinara sauce give you this chemical associated with happiness and peace in a healthy way. Dopamine booster foods like green tea, grilled chicken, or Greek yogurt give you a steady boost of this feel-good chemical associated with motivation, productivity, and vigor.

Step 4: Start cutting down on the number of pitfall foods you eat every day. The best way to do this is using booster food swaps. Here are some of my favorite swaps: Vitamin Water Zero instead of diet soda, coffee with skim milk instead of a latte, whole oranges instead of orange juice, soda water instead of tonic water, balsamic vinegar and olive oil instead of Caesar dressing, Szechuan chicken instead of orange chicken, sashimi and edamame instead of a spicy tuna roll, salsa instead of guacamole, hummus instead of peanut butter, pepper instead of salt, mustard instead of mayonnaise, or a 6? turkey sub on whole wheat instead of the roast beef on white. You'll find even more booster food swaps in Diet Rehab. Long-term, sustainable weight loss is not about depriving yourself. It's about getting what you need in the long-run. Weight loss is not a sprint. It's a marathon, and the race is only with yourself.

Step 5: Keep your momentum going by maintaining these new rituals. Diet Rehab is a 28-day program because it takes about a month for a habit to form in the human brain. When you are adding healthier booster foods and activities every day for 28 days, these choices start to require less conscious effort. If you've ever found yourself driving home when you meant to stop at the store on the way home from work, you understand the unconscious principle that will now help you to make these healthier rituals an easy part of your daily life. Set yourself up for success by surrounding yourself with people who support you in these rituals, not keeping pitfall foods in the house, and building your day around the booster activities that help you to feel good and look great.