Recent research challenges the long-held belief that forming a new habit takes just three weeks. This idea originated from a 1960 self-help book, in which a plastic surgeon observed it took about 21 days for his patients to adjust to their new appearances. However, more recent studies indicate the process is often longer and varies widely.
Researchers in Australia analyzed data from 20 studies conducted between 2008 and 2023, involving over 2,600 participants aged 21 to 73. The studies tracked individuals as they tried to adopt habits such as exercising regularly, flossing, taking vitamins, drinking more water, and eating healthier foods. According to these findings, developing a new habit typically takes anywhere from two to five months. Some people formed habits in as little as four days, while others needed nearly a year.
The distinction between forming a habit and changing behavior is also important. A habit usually involves a single repeated action—such as flossing—which can be prompted by an established routine like brushing teeth. In contrast, behavior change is more complex and may require altering multiple actions throughout the day. For example, reducing sugar intake means making different choices at several points daily, which can present frequent opportunities for lapses.
For those seeking to cut down on sugar consumption or adopt other difficult changes, experts suggest breaking the goal into smaller steps. Analyzing daily routines to identify challenging moments—like morning coffee breaks or late-night snacks—can help pinpoint where adjustments are needed. Substituting lower-sugar alternatives or gradually decreasing portion sizes can make progress easier.
“Break complex behavior into smaller habits, and then tackle those one by one,” according to UCLA Health experts responding to readers’ questions about habit formation. “This makes change more manageable. Be sure to give yourself plenty of time, and grace if you falter, for a new behavior to become your new habit.”
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