Photo used for illustrative purposes.

Heart disease is the No. 1 killer of both men and women — in the U.S. and around the globe. Overall, men over 45 and women over 55 are more likely to have a heart attack than those who are younger.

Dr. Rekha Mankad, a Mayo Clinic cardiologist, says it's crucial to invest now in your heart health for better heart health later.

Can a steady diet of chips, pizza, burgers and fries in your younger years affect you later?

"The choices you make in your teens and 20s are going to affect you years down the road," says Dr. Mankad.

Heart disease progresses slowly, says Dr. Mankad. If you are unhealthy in your teens and 20s, you have a greater likelihood of developing risk factors for heart disease, such as obesity, elevated cholesterol and high blood pressure. This risk won't show up right away and can be silent for years. But you can make changes.

"Healthy choices — such as exercising regularly, maintaining an ideal body weight, eating healthy — the earlier you do these things, and the longer you can maintain them, the more likely you're going to protect your heart for decades to come," she says.

Move more, she says. Add regular daily walks.

"Walking is something you can do pretty easily. And you don't have to take 30 minutes out of your day necessarily. If you don't have that time, you could do 10 minutes in the morning and 10 minutes in the afternoon," says Dr. Mankad.

Take the stairs instead of an elevator, park as far away as you can from an entrance door. Little changes can add up and can become healthy habits leading to better heart health.

"It is never too late to become heart healthy. You can become heart healthy in your 70s and 80s. And there will still be benefit for you," Dr. Mankad says.