A Doctor Says This is How to Develop Healthy Habits and Make Them Last

Brushing your teeth and putting your seat belt on have become automatic healthy habits you do every day. So how long does it take to make things like working out consistently and eating healthy automatic, too?

You may have heard that a habit becomes ingrained after the magic number of 21 days, but Dr. Andersen explained that the science of behavior change has advanced significantly in the past couple of decades, and recently the University College of London shed light on the variability of habit installation.

"The time necessary to adopt a new habit depends on the complexity of the desired behavior," he said. For example, the habit of drinking more water each day may take as little as 18 days to install for some people, while something as complex as interval training for a marathon may take several months.

"Ability, motivation, and environment are all variables that can affect how long it takes to learn a new habit," he explained. "However, the research concluded that most habits can be installed, on average, in 66 days." So if you start a new habit as a New Year's resolution on Jan. 1, most people will turn it into a habit by March 6 (I don't know if that makes me feel better or worse!).

He went on to explain that there's a theory that states there are three psychological phases to make a more difficult habit stick. They are:

Phase 1: First third, you want to quit.
Phase 2: Second third, you are adjusting, and it's becoming easier.
Phase 3: Last part, you are falling into a rhythm, and it's becoming progressively easier.

Throughout these three phases, you will sense the transition when the habit moves from requiring all your attention and feeling uncomfortable to the moment when you sense you are on the final downhill leg and the behavior comes automatic with little effort and no conscious thought. So while forming a new habit may feel difficult at first, knowing it'll get easier may help you stick with it!

If one of your goals is to feel happier, Dr. Andersen said, "organize your life around what matters most to you." You can avoid (or lessen) stress and frustration by prioritizing the tasks that add meaning to your life.

"Organizing our life around the pursuit of what's most important to us appears to convey a type of immunity, an enhanced tolerance to whatever life dishes out."

"Move like you did when you were a kid," he said. "Beyond intentional exercise, it's important to create a lifestyle filled with healthy motion throughout the day." You can clean the house, have a dance party in your living room, ride a bike for fun, walk the dog, or take the stairs instead of the escalator.

"Think back to the activities you enjoyed as a kid, like dancing, shopping, or playing guitar," Dr. Andersen said. "Even something as simple as changing your posture at work can have a dramatic effect on energy balance."

If eating better is your goal, try eating smaller, more frequent meals. Dr. Andersen said it's not just what you eat but also when you eat it. When you fuel your body at regular intervals (rather than sticking with three square meals a day), you may find you have more sustained energy throughout the day. He suggested having breakfast within 30 minutes of waking up and eating every three hours throughout the rest of the day.

"Find your chronotype, which essentially boils down to whether you're a morning person or a night owl," said Dr. Andersen. Once you know your preference and natural energy cadence, you can establish your transition time (when you should be winding down for sleep — typically about one hour before your ideal bedtime). Then develop a nighttime ritual and stick to it.

He said you want to finish chores and work-related tasks in time to transition to bedtime by doing whatever mellows you out such as dimming the lights, lighting candles, listening to soothing music, reading a book, doing some yoga, taking a hot shower, or writing in your journal — try listing three things you're grateful for.