Grit and self-control linked to better weight loss outcomes in couples

New research has underscored how characteristics of "grit" and self-control are associated with better weight loss and weight maintenance outcomes in a study focusing on couples. And that these characteristics can change through behavioral interventions.

This research led by Amy Gorin, professor of psychological sciences and vice provost for health sciences and interdisciplinary initiatives; and Tricia Leahey, professor of allied health sciences in the College of Agriculture, Health and Natural Resources and director of InCHIP, was published in the Journal of Behavioral Medicine.

Previous research has shown that self-control and "grit" (the ability to persevere toward long-term goals) are associated with better weight management outcomes. But no one had ever looked at this phenomenon in couples and whether the phenomenon is associated with weight management habits.

"We wanted to see if there was any sort of effect of couples," says Leahy, who is also director of InCHIP. "That is, do partners have similar levels of self-control? And, does self-control change similarly in couples over time when they're in a weight loss program?"

The 12-month study included a six-month intervention and then a follow-up after another six months with the 64 couples in the study.

The researchers had participants fill out questionnaires to assess their levels of self-control and grit at the start and end of the study. The questionnaire asked participants to indicate to what extent statements like "I am good at resisting temptation" or "setbacks don't discourage me" applied to them.

The researchers also engaged participants in a behavioral weight loss intervention to decrease calorie intake and increase physical activity, teaching them behavior change skills like goal setting and stimulus control.

At the end of the study, the researchers found that, surprisingly, there was no couple effect. Couples did not start out with similar levels of self-control or grit, and, if one member of a couple improved their grit or self-control over the course of the study, their partner did not necessarily experience similar changes.

While couples tend to share weight management behaviors, this study found that there wasn't any social influence between the couples when it comes to self-control or grit. Instead, these are more individual characteristics."

Tricia Leahey, professor of allied health sciences in the College of Agriculture, Health and Natural Resources and director of InCHIP

However, even without specifically focusing on increasing self-control and grit, participants did generally see improvements in these characteristics during initial treatment.

"That suggests that both constructs are malleable," Leahey says. "Sometimes people think of self-control as something that doesn't change. But this study goes to show that, with a behavioral weight loss program that teaches behavior change strategies, we can improve people's self-control or goal pursuit."

The study confirmed previous findings that self-control and grit are associated with better weight management outcomes. These traits were also associated with important behaviors like having a habit of exercise and self-weighing. Grit was particularly important for weight loss maintenance, according to the researchers.

"Weight loss maintenance is a major challenge in obesity treatment," Leahey says. "The fact that we saw that grit was associated with weight loss maintenance, suggests that targeting grit may improve long-term maintenance outcomes."

Given these findings, future studies may consider improving people's grit, or goal persistence, to improve weight management habits, perhaps by focusing on long-term goals for which weight management and/or physical fitness is important such as finishing a road race or coaching a child's soccer team.

Future studies may also consider reducing reliance on self-control and grit via environmental modification. "Our environments tend to be obesogenic in that there are a lot of high-calorie, low-nutrient foods and significant opportunity for sedentary behavior," Leahey says. "Because of this, it's not surprising that we have high rates of overweight and obesity. By modifying our environments, we can make it easier for people to lead healthier lives and not have to exercise as much self-control and grit."