One little promise transformed Jessica Nord from a self-described "living wreck" whose stress and worry meant restless nights and trouble eating into a person who feels calm, peaceful and relaxed just a few months later.

Nord's extreme stress was set off by a breast cancer diagnosis in October. Soon afterward, at an appointment with Chris Hafner, a licensed acupuncturist and owner and director of Hafner Acupuncture Stress Reduction Clinic, she promised him she'd sign up for yoga class the next morning. The relief she felt from that one class gave her the momentum to continue yoga and make more changes. She joined a women's group at church and starting eating better and exercising frequently. She describes the difference it's made as "totally immense."

Like Nord, more people are realizing how dramatically lifestyle changes improve their ability to deal with stress and mitigate its effects on the mind and body, Hafner said. Think about how common yoga and meditation classes are today compared with 10 years ago. "We live at a time when there's an increasing awareness of the importance of developing good coping skills," he said.

The bad news is, there's a long way to go, and it's all too often that people respond to stress counterproductively, with methods such as overeating, consuming caffeine or distracting themselves with TV or shopping. Without helpful coping and self-care skills, stress continues to take a toll on physical, mental and emotional health, said Dr. Timothy Culbert, medical director for the Integrative Medicine program at Children's Hospitals and Clinics of Minnesota.

Stress is known to contribute to physical problems that are occurring at record rates, including hypertension, heart disease, sleep disorders and inflammatory diseases, he said. And the number of people dealing with stress-mitigated emotional and behavioral disorders, such as anxiety and depression, continues to rise and affect adults as well as teens and kids.

"For many of us, being overscheduled and busy and having too much to do is the norm," Culbert said. "Even if you're doing things you really enjoy, you need downtime and time to refresh and take a break."

Adequate downtime, along with simple choices about food, sleep and exercise directly influence your physiology, brain chemistry, mood and ability to cope with stress, said Dr. Henry Emmons, with the Penny George Institute for Health and Healing at Abbott Northwestern Hospital and author of "The Chemistry of Joy."

People have sympathetic and parasympathetic nervous systems in their bodies, Emmons explained. The sympathetic system is also known as the fight-or-flight response, which is designed to help survive danger. When it's activated by a perceived or real threat, it tells the adrenal glands to pump out stress hormones, such as cortisol, which shut down certain body functions and rev up others in preparation for a fight or flight. The parasympathetic nervous system does the opposite -- it helps the body calm down and recover.

Then within the brain there are fear circuits, which are also meant to help with survival. When these circuits are activated by mild, vague threats or continued stress, people become vigilant, emotionally reactive and prone to anxiety, worry, panic and obsessive, ruminating thoughts, Emmons said.

Lifestyle choices further activate or calm these various systems, Emmons said. Here's how:

Exercise. When your body is stressed and prepared to fight or run, it's full of stress hormones. If you're sedentary, those hormones will continue to circulate and cause damage to your body. Vigorous exercise, however, burns off those hormones. Exercise also releases feel-good chemicals like serotonin.

Caffeine. If you need caffeine to wake up or get through the day, it's masking other problems, perhaps an overscheduled lifestyle. Caffeine increases the effects of your body's own stimulating neurotransmitters: norepinephrine and dopamine, which are similar to adrenaline in their effects. Caffeine and these natural stimulants provide short-term energy, focus and even a lifted mood. But in the long term, caffeine depletes your stores of norepinephrine and dopamine, leaving you more tired, sluggish and down than you were before the caffeine habit.

Sleep. If you don't get enough sleep (most people need between seven and nine hours), your body interprets that as a major stress signal. Lack of sleep triggers the body to increase production of the stress hormone cortisol, which makes it harder to fall asleep and stay in a deep sleep because on some level your body and brain think they need to stay alert for danger. Cortisol also tells you to eat more, leading to weight gain. Adequate sleep, on the other hand, repairs your body, sharpens your mind and stabilizes emotions.

Food choices. People who are stressed often crave and overeat sugar and simple carbohydrates, like chips, cookies and white bread or pasta, because those foods provide a fast release of the feel-good chemical serotonin. But eating this way causes a blood-sugar crash a couple hours later, leaving you tired and moody. Plus, sugars and simple carbohydrates lead to fat buildup around the mid-section. And belly fat acts like adrenaline -- it actually pumps out more stress hormones. Complex carbohydrates, such as sweet potatoes, brown rice or oatmeal, allow your brain to gradually process more serotonin for the long haul. Eating protein and healthy omega-3 fats, found in fish, walnuts and flax, will also improve mood. B vitamins, which are abundant in fresh leafy greens and in chemical-free, pasture-raised meat, are another important factor because they're needed for serotonin production.

Quieting body and mind. The body and mind need periods of activity followed by quality rest and recovery in order to be healthy. Meditation, yoga, prayer and music therapy all activate the parasympathetic nervous system, which soothes the body and mind and helps with recovery from stress. Practices that quiet and connect the mind, body and spirit also calm the brain's neural circuits.

Sarah Moran is a freelance health writer in Minneapolis.