If you’re ready to take control of your health, start by washing your hands for 15 to 20 seconds, about as long as it takes to sing “Happy Birthday” twice. Doing this simple act, while avoiding certain behaviors — smoking, excessive drinking and eating too much — can dramatically improve your health, says internist William Meller, who specializes in evolutionary medicine in Santa Barbara, Calif.

Prevention goes well beyond the mammograms, prostate screenings or blood tests that we can get at the doctor’s office. It’s the little steps you take that can keep you healthy.

“Ideally, prevention should also emphasize healthy lifestyles, a practice that isn’t only health-conscious, but (is) inexpensive,” says James Pivarnik, president of the American College of Sports Medicine.

Here are 10 easy ways to get started:

1. Take a walk.

Humans are designed to be on the move, Meller says. “Walking triggers all of our bodily systems: digestion, stress relief, thinking and preparation for sleep.” It’s easy, simple, free and confers the benefits of exercise without the risk of damage from more energetic pursuits, Muller says. Walk every day — barefoot is fine — and get a pedometer to track your steps, shooting for a minimum of 10,000. Stay committed by setting walking dates with a friend.

2. Keep a food journal.

Writing down everything you eat can double your weight loss, according to a study published in the American Journal of Preventive Medicine. “The more food records people kept, the more weight they lost,” says lead author Jack Hollis, a researcher at Kaiser Permanente’s Center for Health Research. Scribble down your dietary transgressions on a note pad, use an online food journal or send yourself text messages. “It’s the process of reflecting on what you eat that helps us become aware of our habits, and hopefully change our behavior,” says Dr. Keith Bachman, a member of The Kaiser Permanente Care Management Institute’s Weight Management Initiative.

3. Stop drinking soda.

Soda and other caloric, sugar-sweetened beverages have contributed to skyrocketing rates of obesity and Type 2 diabetes. But there’s also evidence that drinking diet soda leads to weight gain. Researchers suspect that tricking the brain — getting sweetness without the calories — makes you crave more sugar than ever. Your best bet is to stop drinking calories altogether, says obesity specialist Dr. Yoni Freedhoff. His most confused patients seem to be doing everything right but may have two glasses of milk, one glass of juice and one glass of wine a day. “That’s roughly 40 pounds of liquid calories per year,” he wrote on his blog, Weighty Matters. Freedhoff’s advice: Don’t rely on beverages for nourishment. “A well-balanced diet replete with fruits, vegetables and proteins should satisfy all of one’s nutritional needs,” he says. “Liquid calories are not satiating and in studies tend only to add calories to a meal,” says Freedhoff, founder of Ottawa’s Bariatric Medical Institute, a multidisciplinary weight-management center.

4. Strengthen your muscles.

If you want to keep your muscles from weakening as you age, start strength training. It’s “the only style of exercise that maintains and increases lean muscle tissue and burns between 22 and 36 calories per day,” says personal trainer Jim Karas. He suggests starting with push-ups for the upper body and lunges and squats for the lower body. “Move slowly, and think about the muscles you are engaging. One slow set of 10 is all you need, but make sure to fail,” which means you can’t perform another repetition.

5. Chill out.

Stressed-out people are more vulnerable to colds and other viruses, they take longer to recover from illness and they gain more weight than their relaxed counterparts, research has shown. We also know that “the inability to feel in control of stress, rather than the stressful event itself, is the most damaging to immunity,” wrote Joan Borysenko in “Mending the Body, Mending the Mind.” Another stress expert, Debbie Mandel, likes to lift weights when her stress levels creep up. “Then I’m ready to reframe negatives into positives to turn stress into strength,” says Mandel, the author of “Addicted to Stress.” In addition to exercise, deep-breathing techniques, meditation, tai chi and yoga are proven stress relievers.

6. Eat out less.

We often use restaurants in the same way our parents used supermarkets, one of the main reasons for the dramatic global rise in chronic diseases such as obesity, Type 2 diabetes and heart disease, says Freedhoff. “Nutrition and calories aren’t intuitive,” he says. “When restaurant salads can have more calories and fat than a Big Mac, you know you’re putting your health at risk. You’ll save more than your money by eating meals in. You might even save your life.”

7. Be a social butterfly.

Human beings are social creatures, if only because we need to reproduce. But research has shown that joining a club or sports team, belonging to a church group or keeping in contact with friends creates a sense of social identity that can help significantly reduce your risk of having a stroke, dementia and even the common cold. “We do not outgrow our need for others,” according to the MacArthur Foundation Study of Aging in America. “Loneliness breeds both illness and early death.”

8. Get your zzzzzzzz.

Sleeping well is the single most overlooked factor critical to good health, especially during the flu season, says sleep specialist Dr. Rubin Naiman, an assistant professor at the University of Arizona’s Center for Integrative Medicine. But because focusing on doing all the right things before bed can make it harder to sleep, Naiman suggests lightening things up, perhaps by watching comedy on television before bed. “Too often sleep is approached with an anxious mind and heavy heart,” he says. “Laughter is good medicine — and good sleep medicine. I recommend it over sleeping pills.”

9. Eat whole foods.

Whole foods — fruits, vegetables, legumes, nuts, seeds, eggs and whole grains — are unprocessed and unrefined and typically don’t have added sugar, salt or fat. They often have a low glycemic index, which means they don’t raise blood sugar and insulin levels as quickly as processed foods. Choose a baked potato instead of French fries, eat whole wheat bread instead of white bread, or start the day with oatmeal, rather than a sugary breakfast cereal. “I eat as many fresh veggies and fruits as possible and stay away from anything in a bag, a box or a can,” says Yvonne Conte of Syracuse, N.Y., the author of a guidebook to living a happier and healthier life. “When I started this, I lost 22 pounds. And it has stayed off. Best thing I ever did.”

10. Find your passion.

Do things that bring meaning to your days, says Patricia Boyle, a neuropsychologist in the Alzheimer’s Disease Center at the Rush University Medical Center in Chicago, whose research has shown that having a higher purpose can reduce the risk of death among older adults. “Purpose is cognitively stimulating, and this is very much along the lines of the adage ‘Use it or lose it,’ which certainly has merit,” says Dr. Thomas Perls, director of the New England Centenarian study.