As we approach the end of January 2025, many people may be finding it hard to stick to their New Year’s resolutions. However, new research from the University of South Australia suggests that forming a healthy habit can take longer than commonly believed.
In the first systematic review of its kind, UniSA researchers discovered that new habits can begin to form within about two months (with a median of 59-66 days) but can take up to 335 days to fully establish. This finding could help shape health interventions aimed at promoting healthy behaviors and preventing chronic diseases.
Chronic diseases, such as type 2 diabetes, heart disease, lung diseases, and stroke, are major contributors to disease burden in Australia, and many of these conditions can be prevented by changing unhealthy habits.
Dr. Ben Singh, a University of South Australia researcher, says that contrary to the popular belief that it takes just 21 days to form a new habit, the process is far longer. “Adopting healthy habits is crucial for long-term well-being, but forming these habits—and breaking unhealthy ones—can be difficult,” Dr. Singh explains.
“At the start of the year, many of us set goals like being more active, cutting back on sugar, or making healthier food choices. While it’s often said that it takes only 21 days to form such habits, these claims are not evidence-based.”
The research revealed that habit formation begins around two months but can take anywhere from four days to nearly a year to fully take hold. “It’s important for those working toward healthier habits not to give up after the mythical three-week mark,” Dr. Singh says.
The study, which involved over 2,600 participants, also identified several factors that influence successful habit formation. “How frequently we perform the new activity, when we do it, and whether we enjoy it or not all play a role in whether a habit sticks,” Dr. Singh adds.
For example, habits are more likely to form if incorporated into a morning routine, and if they are enjoyable. “Planning and setting clear intentions can also help. Making time for healthy habits, like preparing gym clothes the night before a walk or having a healthy lunch ready, sets you up for success.”
While more research is needed, these findings could guide public health programs and personalized initiatives to support long-lasting behavior change.
