Turning 40 is a milestone — and a good moment to take stock. Many of the health changes that shape the decades ahead begin quietly in midlife, which means the choices made now can have an outsized impact. These ten habits are a practical place to start.

1. Maintain a healthy weight

Carrying excess weight, especially around the midsection, raises the risk of heart disease, type 2 diabetes and several cancers, including postmenopausal breast cancer. Reaching and maintaining a healthy weight lowers those risks for both men and women and can ease some menopausal symptoms.

2. Build and keep muscle

Adults gradually lose muscle mass starting around their 30s — roughly 3% to 8% per decade — and the pace picks up with age. Resistance training two or more days a week, whether with weights, bands or body-weight exercises, helps preserve strength, metabolism and balance.

3. Pay attention to your thyroid

Fatigue, weight gain or difficulty losing weight aren't always about diet and exercise. Thyroid disorders become more common in midlife, particularly among women. If symptoms sound familiar, ask your doctor whether thyroid testing makes sense.

4. Quit smoking

Stopping smoking at any age adds years to life and sharply reduces the risk of heart disease, stroke, lung cancer and many other illnesses. Benefits begin within weeks of quitting and keep growing over time.

5. Know your numbers

Blood pressure, cholesterol, blood sugar and weight become increasingly important after 40. Regular checks help identify rising risk early, when lifestyle changes or treatment are most effective. For a direct look at heart risk, some people add a coronary calcium scan.

6. Take care of your teeth and gums

Research has found associations between gum disease and heart disease, along with other chronic conditions. Brushing, flossing and regular dental visits are good for more than your smile.

7. Protect your vision

Vision changes are common after 40, and age-related macular degeneration is a leading cause of vision loss in older adults. A diet rich in leafy greens and colorful fruits and vegetables, avoiding smoking and wearing UV-blocking sunglasses can help protect your eyes. Schedule regular eye exams.

8. Eat more fiber, fewer sweets

Metabolism tends to slow with age, making weight gain easier. Emphasize whole grains, vegetables, fruits, legumes, lean protein and low-fat dairy, and limit added sugar.

9. Know your family history

If parents or grandparents had heart disease, cancer or diabetes — especially at younger ages — your own risk may be higher. Share that history with your doctor so screening can be tailored to you.

10. Prioritize prevention

An ounce of prevention really is worth a pound of cure. Keep up with recommended screenings for your age, and consider whether preventive imaging fits your situation. A full body scan can reveal some conditions months or years before symptoms. Options and costs are explained on the Advanced Body Scan pricing page.