Choosing the right day to begin a diet could be the key to sustained weight loss, experts say. Starting fresh with health goals can be difficult, but timing matters more than many realize.
Researchers at the University of Pennsylvania have found that Monday stands out as the optimal day to kick off new diet and exercise plans. According to co-author Jason Riis, certain days act as “temporal landmarks”—moments when people naturally adopt a forward-thinking mindset. “On these days, you view yourself differently,” Riis explains. “You become more motivated to embrace change.”
Hengchen Dai, Riis’s fellow researcher, adds that people often feel inspired to reinvent themselves at these milestones. “They think, ‘I am going to be a new person and break free from past failures,’” she says. This mindset shift is crucial for initiating lasting behavior change.
READ MORE: Jeremy Clarkson Opens Up About Relationship with Lisa Hogan Amidst Clarkson’s Farm Success
READ MORE: Bradley Walsh’s Heartfelt Promise to Family as He Opens up About Slowing Down
The study analyzed Google search trends, gym attendance at the University of Pennsylvania, and data from a behavioral commitment website where users risk financial penalties if they fail to stick with new goals. Across all measures, Monday emerged as the peak day for starting health-related resolutions.
But the power of Monday extends beyond dieting. Dai points out, “Monday symbolizes a fresh start,” making it an ideal day to tackle various life changes. Psychologist Ann Kearney-Cooke of the Cincinnati Psychotherapy Institute agrees, saying, “Mondays provide an energy boost that can help people get motivated.”
However, she also cautions about the potential for burnout by week’s end. If setbacks occur mid-week, Ann encourages resilience: “The key to lasting change is starting over at the next meal or the next morning, rather than waiting until the following Monday.”
The study did not find a specific “worst day” to start a routine but advised avoiding new commitments when feeling particularly low on energy or willpower.
While this research focused mainly on when to begin, psychologist John Norcross from the University of Scranton notes that people who make resolutions tied to meaningful temporal landmarks—such as New Year’s Day—often have higher success rates.
If weight loss is a goal, consulting a healthcare professional or accessing resources like those provided by the NHS can offer valuable support.