Being happy is not just a state of mind ? it's also a state of the body. What I found in my research for my book, Happy for No Reason: 7 Steps to Being Happy from the Inside Out, is that our bodies are actually designed to support our happiness. Renowned neurophysiologist Dr. Candace Pert documented this mind-body-happiness link, explaining that when we're happy, we're alive and buzzing with "happiness juices," the chemicals of body and brain that underlie our positive experiences.

Your brain contains a veritable pharmacopoeia of natural happiness-enhancing drugs ? including endorphins (the brain's painkiller, three times stronger than morphine), serotonin (which naturally calms anxiety and relieves depression), oxytocin (the bonding hormone), and dopamine (which promotes alertness and a feeling of enjoyment) ? waiting to be released to every organ and cell in your body. Because your brain's pharmacy is open 24 hours a day, you can create your own supply of these happiness chemicals any time you want. And when your cells are happy, you're happy.

What you eat can play a crucial role. For years, my cells were unhappy because I nourished them poorly. When I was very young, my diet consisted mainly of crisp bacon, juicy hamburgers, Hostess cupcakes, crackers filled with a mysterious substance called "processed American cheese food product," and snowy-white Wonder Bread ("builds strong bodies twelve ways!"). Fruits and veggies came in only three flavors: carrots, celery, and apples, of which I ate the barest minimum so I'd have lots of room for McDonald's fries and shakes. I was always exhausted, so I'd rev myself back up with sugar, raiding the freezer for ice cream at all times of the day and night for an energy boost. Naturally, I'd enjoy my sundaes with a can of Tab ? who wanted the extra calories from a regular Coke?

I fed my growing body so well that grow it did ? an extra twenty pounds, which is a lot when you're five feet tall and 16 years old. So when I got to college, I decided to clean up my food act. I drank my last can of Tab when I was 17, phased out the sugar, and became a vegetarian. At first this burst of virtuousness was prompted by my fear of wearing shorts in public. But I quickly discovered that any weight-loss triumphs paled in comparison to the sky-high levels of energy I felt once I'd gone off the bad stuff. I felt so much lighter, happier and clearer ? I felt more "me." Now that I understand the relationship between my energy, mood, and food, I don't ever want to go back to the "Wonder Bread Years" and non-stop exhaustion.

If you too would like to take advantage of your brain's happiness-enhancing chemicals, here are a few general guidelines to get you eating in a way that not only will improve your health, but will make your cells happy.

The Make-Your-Cells-Happy Nourishment Guide:

1. Go for Happiness-Building Foods ? Fresh and Whole: A balanced diet of fresh, whole foods gives our brains the necessary raw materials to ensure that we produce abundant happiness neurotransmitters every day. Eating whole foods means giving your body food that's as close as possible to the way Nature made it. Avoid what I call "fake food" that comes out of a box or a can, which is many times removed from its original source by processing, preservation, and synthetic packaging. Shop the outer aisles at your supermarket, where you'll find the fruits and vegetables, fresh meats, fish and poultry, not the inner ones where the boxed, canned, and packaged foods live. Buy whole grains, organic produce, and hormone-free meat, dairy and poultry products. Yes, the food generally costs more, but you'll more than make up for it in fewer doctor visits and a healthier life.

2. Keep the Water Flowing: Being dehydrated is a no-no for happy cells. We need water because our bodies are mostly water! In order to fully take in the nourishment in our food, our bodies require the chemical elements of hydrogen and oxygen found in H₂O. People often feel hungry when what their bodies actually need ? is water. The next time you feel like reaching for a snack, take a sip or two of water first. Even better, do as the experts recommend, make it a habit to drink half your body weight in ounces each day.

3. Lose the Happiness-Robbing Foods:

? Shake the Sugar: Do you know how hard it is to get health experts to agree on anything? Yet every one I interviewed agreed that the biggest happiness destroyer in our diets is white sugar. It's powerfully addictive and wrecks havoc with your brain, causing depression, anxiety, and that sluggish, low-energy state you recognize when your forehead hits the desk at 3:00 p.m. The synthetic sugar substitutes are unfortunately no better; numerous reports point to potentially negative side-effects. When you take your sugar in its natural form ? as in fresh fruit ? the body can handle it better.

? Curb the Carbs: In the carb department, "whole" is the operative word. When you eat processed high-glycemic grains, such as white bread, white rice, or pasta and pastries made with white flour, your blood sugar levels spike and crash, constantly altering your mood and energy levels. The Standard American Diet (SAD?what an appropriate acronym!) relies on too many starchy, refined carbs. Switching to whole grains like brown rice, quinoa, and millet, is a simple, but effective trick for feeling healthier and happier fast.

? Kick the Caffeine: When we need a lift, a lot of us reach for the caffeine jolt of coffee or soft drinks. Caffeine blocks the transmission of the brain chemical called adenosine, which results in more adrenaline pouring into the bloodstream. After drinking a cup of coffee or a soda, you feel alert, motivated and stimulated, but that high reaches its peak in 30-60 minutes, and then down you go. Instead, try decaffeinated green tea (regular green tea has caffeine), which not only offers powerful anti-oxidant protection to help make cells happy, but gives you a more sustainable level of energy.

Here's to happy eating that makes your cells sing!