Some aspects of healthy living are ageless. But it's undeniable that challenges change with age. With that in mind, we asked local health experts for their best advice on health for adults in every decade of life. This week, we cover the 20s, 30s and 40s; next week, you'll find tips for the 50s and beyond.

The 20s

1. Build good dietary habits. "Now it's time for a new chapter; one that can have lasting and empowering impact on the rest of your life," said Michael Munson, owner of Thrive Fitness & Wellness.

Registered dietitian Ashvini Mashru urges 20-somethings to make healthier choices. "This is the time to say good-bye to some of your favorite 'go-to' foods and drinks that have zero nutritional value: sodas, sugary fruit punches, sugary coffee drinks, many fast foods and even processed meats like hot dogs." Try making better meals at home featuring veggies, lean meats and whole grains, Mashru advises. You'll even save money over eating out.

2. Schedule regular checkups. "You need to make sure there is nothing going on regarding your health that is beyond your control," said Charlie Seltzer, physician and owner of Lean4Life Weight Loss and Fitness Solutions. Deep fatigue could just be the result of late nights. However, it could also be an indicator of anemia - not uncommon for young, menstruating women - or hypothyroidism, which can lead to high cholesterol, heart problems, low bone density and even depression.

3. Make heart health a priority now. "Autopsy studies in young soldiers and accident victims in their 20s (and even earlier) have shown the presence of significant coronary artery disease or building up of cholesterol plaques in the heart arteries," said Vincent M. Figueredo, associate chair of medicine and chief of clinical cardiology at Einstein Medical Center. "Regular exercise, a healthy diet, and no smoking will decrease the buildup of cholesterol in the heart arteries and reduce the risks of future heart attacks."

4. Don't skimp on sleep. Even if you think you feel fine without it, not getting enough shut-eye is associated with heart disease, obesity, high blood pressure and stroke, so if you are having sleep problems, see a health professional.

5. Build strong and flexible muscles. Dana Auriemma, owner of Freehouse Fitness Studio, recommends a balanced workout routine for 20-somethings that includes a good dose of strength training or sculpting, plus stretching after every workout.

"Having strong and flexible muscles protects your joints and keeps your body in healthy alignment - and that keeps you looking and feeling good through later decades of your life," Auriemma said.

Hector E. Bones, managing partner of Bones Fitness Partners, noted that consistency is key.

"Don't be a weekend warrior. Work out three to four times a week, and know that this is a process."

The 30s

1. Schedule everything. "Treat your food choices as you do other parts of your life and build it into your schedule," advises Jessica Fritton, a registered dietitian at Family Food LLC. "Set aside one day a week to go food shopping, and five minutes every morning to map out your day with respect to food."

"Make appointments to work out, whether that means getting them done first thing before the day starts, or making time during the day," said Abbie Chowansky, co-owner of Focus Fitness.

2. Cope with stress better. "Stress increases the risk of a variety of diseases, in particular, hypertension and coronary heart disease," said Kimberly Dasch-Yee, assistant professor of psychology at Holy Family University.

"Common stressors for people in their 30s, such as being unhappy in their job, or dissatisfied with their relationships, often are at least somewhat controllable," she said.

"For example, when overwhelmed with work, it can be more helpful to cope by planning and breaking the work into smaller manageable chunks."

For stressors that are out of your control, meditation or self-distraction (watching funny TV shows or movies) is more effective.

3. Support your bones. "For healthy individuals, bone mass peaks at around age 35, after which, bone loss begins to occur," explained Jennifer Laurence, a registered dietitian at Family Food, LLC.

Calcium, Vitamin D, and Vitamin K are bone-supporting nutrients found in dark leafy greens, sesame seeds, fish, eggs, and dairy products she said. "Also include weight-bearing exercise, which can slow or reverse bone loss."

4. Mind your metabolism. In your 30s, count on burning "about 100 to 200 fewer calories each day" than you used to, Fritton said. "Unless you want to gain weight, you'll have to eat a little less than you did in your 20s."

So switch your drink to water. "One glass of wine, a can of soda or beer has about 100 to 200 calories, so cutting this out is a great place to start," Fritton added.

5. Schedule screenings. Theresa Birardi, a member of Crozer-Keystone's Family Physicians, advocates certain routine screenings for 30-somethings. "Skin cancer is the number-one cancer diagnosed every year, but many people don't think to have themselves checked," Birardi said.

For women, that also means getting a pap test for cervical cancer every three years until 65.

Keep up on vaccines; tdAP (Tetanus-Diphtheria) is recommended every 10 years at maximum and there are pneumococcal vaccines for smokers and patients with asthma. The whooping cough vaccine also should be kept up to date.

Knowing your family history is crucial. "Many people are not aware that significant problems could show up in your 30s and 40s like breast cancer, familial hypercholesterolemia or diabetes," Birardi said.

The 40s

1. Know your risk for type 2 diabetes.

Type 2 most commonly emerges in the 40s, but often can be stopped through healthy lifestyle. Stephen Permut, professor and chair of the department of family and community medicine at the Lewis Katz School of Medicine at Temple University, suggests taking a self-screening test at DoIHavePrediabetes.org.

2. Pay attention to posture. A lifetime of bad posture can lead to a severe curvature of the spine called postural kyphosis. Women with osteoporosis are particularly at risk.

3. Talk about sex. Cardiovascular disease, diabetes, obesity and depression can lead to problems in the bedroom. Medications and chronic illness can obstruct blood flow to the penis in men and cause vaginal dryness and painful intercourse in women, said Bruce B. Sloane, a specialist in age management at Philadelphia Urology Associates. "Oftentimes, patients are not comfortable talking to their doctor about sexual health, and the doctor doesn't always think to ask about it," said Kristene Whitmore, medical director of the Pelvic and Sexual Health Institute at Drexel University's College of Medicine. "But there is no way for us to help unless you identify the problem."

4. Emphasize good-quality foods. Reducing your intake of processed food and added sodium as well as beverages with added sugar is also recommended. Better foods to eat include berries, oranges and peppers. High in antioxidants, they will help fight the signs of aging. And garlic, onions and green vegetables in your diet will promote better heart health.

5. Make yourself a priority. "Our 40s are often a time of many demands - family responsibilities, more responsibilities at work - while trying to carve out at least a little time for exercise and hobbies," said Sarah M. Whitman, clinical assistant professor of psychiatry at Drexel University College of Medicine. "This is also the time that you might be taking on more caretaking for aging parents."

Despite all these demands, it's important to practice self-care: eating right, exercising, getting enough sleep, and including relaxing and fun activities in your daily life.

Whitman suggests trying to be mindful of the rewards and joys in each day, and practicing gratitude and mindfulness. If your life needs a correction - either minor or major - take some time to figure it out now.

Tracey Romero is a Philadelphia writer who specializes in health topics.