Why it's hard to change unhealthy behavior -- and why you should keep trying

Researchers say successful change comes only in stages. How long it takes is an individual matter.

When it comes to health recommendations, we mostly know the drill: Exercise most days of the week; eat a varied and nutritious diet; maintain a healthy weight; get enough sleep; keep up with medical screenings for blood pressure, cholesterol, and blood sugar; don't smoke; and limit alcohol to seven drinks a week. Reducing stress, improving relationships, and developing new interests or hobbies also contribute to healthy living.

Making healthy lifestyle changes affects not only our risk for disease and the way we feel today but also our health and ability to function independently in later life. What we do for ourselves is often more important than what medicine can offer us. Yet making healthy lifestyle changes is easier said than done. Even when we're strongly motivated, adopting a new, healthy habit — or breaking an old, bad one — can be terribly difficult.