How to Form a Healthy Habit (Does It Really Take 21 Days?)

Most of us have a long list of healthy habits we're trying to form. Eating more vegetables, hitting the hay earlier, meditating more — you get the picture.

While you might have good intentions, building a healthy habit can be hard. Ask anyone who's tried — and failed — to stick to a New Year's resolution.

Still, research shows that people with healthy lifestyles rely on habits — not willpower — when making choices, says clinical psychologist Gary Foster, PhD, chief scientific officer at WW (formerly Weight Watchers) and author of ‌The Shift: 7 Powerful Mindset Changes for Lasting Weight Loss‌‌.‌

So how can you hack the habit-making process to help you stick to your health goals? Here, Foster explains how to create (and stick) to a healthy habit (including whether it really takes 21 days).

While we spend a lot of time talking about "healthy habits," most of us don't really know much about the nuts and bolts of what makes a habit. Like, for instance, that a habit consists of several components.

A habit is formed when a specific cue 1) leads you to perform a specific behavior, which 2) is quickly followed by a positive effect, i.e., reward, Foster says. To illustrate this point, consider the following example: Every night after you take a shower (cue), you meditate for five minutes (specific behavior), which helps you relax before bed, improving your sleep quality (positive effect/reward).

"This 'loop' is repeated so that the associations become nearly automatic, so now you behave in this new way with minimal effort, consistently and over a long period of time," Foster says.

Habits come in handy especially when we're stressed or tired, i.e., times when it's harder to make consciously healthier decisions, Foster says.

Is 21 days really the magic number? "That's a common misconception that I hear a lot, but the evidence just isn't there to support 21 days, or really, any concrete amount of time," Foster says.

That echoes the findings of a July 2009 study in the ‌European Journal of Social Psychology‌ (which is still the most often cited study on the topic). Researchers found that it took anywhere from 18 to 254 days to change a habit related to healthier eating, drinking or exercise. On average, it took most people 66 days to make the habit automatic.

The takeaway here is that habit formation — like most things in life — varies from person to person. "The time it takes to develop a habit is dependent on several factors, such as how complex the habit is and how consistently you're able to adopt it into your day-to-day routine," Foster says.

Put another way, there's no one-size-fits-all timeframe for forming a healthy habit.

"The shorter the distance between your current state and your desired goal, the likelier you are to succeed. And when you succeed, the celebration will further fuel the journey — small successes lead to big successes."

Habit formation is a process, and often a slow one that's not always linear. By understanding how it works, you have the power to change your behaviors and create healthy habits, Foster says. Here, he breaks down the steps involved in building healthy, long-lasting habits.

When you're setting new goals, the more specific the better, Foster says. That's because it's hard to evaluate your progress if your goal is vague, such as "eat healthier."

"For instance, you can eat healthy and nutritious meals many times during the week, but suppose at other points you ate something unplanned (almost a given, right?) — how do you assess whether you achieved the rather broad 'eat healthier' goal?" Foster says.

Rather than "eat healthier," you might set a goal of eating an orange three days a week on Mondays, Wednesdays and Fridays at 3 p.m. The specificity of this behavior leaves no room for confusion, so it's easy to evaluate when you've achieved it.

Any goal you set should feel realistic and manageable for your life, Foster says. In other words, it should be something you're capable of achieving and incorporating into your regular routine.

"One of the keys to sustaining healthy habits is by making smaller, incremental goals as opposed to one lofty one," Foster says.

So, if you're new to weight lifting, it's unrealistic to strive to become a bodybuilder in a month. On the other hand, committing to two half-hour strength-training workouts a week is quite doable.

"The shorter the distance between your current state and your desired goal, the likelier you are to succeed," Foster says. "And when you succeed, the celebration will further fuel the journey — small successes lead to big successes."

Now that you know ‌what‌ your goal is, ask yourself ‌how‌ you'll achieve it. Create an action plan and outline the small steps you'll need to accomplish the behavior, Foster says. "The more you define how to navigate the road, the better," he says.

Let's take the earlier example: If you want to build the habit of eating oranges three times a week, how will you ensure you have oranges in the house come Monday afternoon? In this case, perhaps the small steps in your action plan include going to the market on Sunday morning and using a grocery app to help you remember to buy oranges.

"As tedious as this might sound, this approach is truly liberating," Foster says. It puts you in the driver's seat and helps you generate a roadmap for long-term success.

"A cue is, simply put, the thing that will prompt you to act on the behavior," Foster says. "Choose a cue that you encounter often — say, a certain time of day in a recurring setting — and be consistent, because consistency drives repetition, helping to form the habit."

For example, when you put your kids down every Sunday night, that's your cue to start meal prepping for the week ahead. "Soon enough that act becomes an automatic impulse that, almost without thinking, results in engaging in this helpful and effective behavior," Foster says.

"When we're forming new habits, it's important to experience some type of reward that encourages us to repeat the behavior again and again," Foster says. "You can choose a behavior that's naturally reinforcing on its own or build in a reinforcement."

For example, if you're building a habit of jogging in the morning, positive reinforcement can simply be the runner's high or a feeling of satisfaction for logging a desired distance, or it can take the form of a more concrete incentive like a relaxing post-run bubble bath.

You can also pair the activity with something that makes you feel good at the same time, Foster says. For instance, enlist a family member or friend to be your yoga buddy, watch your favorite TV show on the treadmill or listen to your preferred podcast while meal prepping.

All this is to say, "when the actions we take are rewarding or satisfying, we're more likely to keep doing them," Foster says.

Your surroundings can make or break you when it comes to building better-for-you habits. For example, a room full of distractions — like a TV or game console — will work against you if your goal is to procrastinate less.

That's why designing your environment to promote healthy habits is so important, Foster says. Think about what you need to stick to your habit, and structure your setting accordingly. For instance, if you're trying to lose weight, find a place for your home office setup that's away from the kitchen where snacks might be in plain sight.

"If you struggle to sustain new healthy behaviors, you're not alone," Foster says. "Setbacks will take place — that's a reality."

The key is consistency along with realistic expectations and patience. "True habits are slow to form," Foster says. So, when you have a setback — which you inevitably will — be kind to yourself; it's part of the process.

"Think about it this way: You created a plan to adopt this new behavior, and you deserve to celebrate the steps, not just when you reach the final destination," Foster says. The interim rewards will inspire you and keep you going in the desired direction, he adds.

So take time to acknowledge all your hard work along the path.