The study, published in Health Psychology, showed that adults who followed structured eating patterns during a 12-week behavioral weight loss program achieved better results than those who frequently changed their food choices. Participants who repeated meals and kept calorie intake stable over time lost more weight than those with more varied diets.

“Maintaining a healthy diet in today’s food environment requires constant effort and self-control,” said lead author Charlotte Hagerman, PhD, of the Oregon Research Institute. “Creating routines around eating may reduce that burden and make healthy choices feel more automatic.”

Tracking Habits and Study Design

To explore the role of routine, researchers analyzed detailed, real-time food logs from 112 adults who were overweight or obese and enrolled in a structured weight loss program. Participants recorded everything they ate using a mobile app and weighed themselves daily with a wireless scale.

The analysis focused on the first 12 weeks of the program — a period when participants are typically most engaged and provide the most accurate data about their eating habits.

Measuring Calorie Consistency and Meal Repetition

Researchers evaluated how structured each participant’s diet was using two measures. One was caloric stability, which examined how much daily calorie intake varied across days and between weekdays and weekends. The second was dietary repetition, which tracked how often participants logged the same meals and snacks instead of regularly choosing new foods.

Greater Consistency Linked to Better Results

Participants who frequently ate the same foods lost an average of 5.9% of their body weight, compared with 4.3% among those who ate a wider variety of foods. More consistent calorie intake was also associated with greater weight loss. For every 100-calorie increase in daily fluctuation, weight loss decreased by about 0.6% over the study period.

These results suggest that simplifying food choices, such as relying on a set rotation of meals and keeping calorie intake steady, may help people develop habits that are easier to maintain. However, the researchers note that the findings show a correlation, not cause and effect, and that factors like motivation or self-discipline may also influence outcomes.

Rethinking Variety in the Modern Diet

The researchers also point out that earlier studies have linked dietary variety to better overall health. However, those findings typically focus on variety within healthy food groups such as fruits and vegetables.

“If we lived in a healthier food environment, we might encourage people to have as much variety in their diet as possible,” Hagerman said. “However, our modern food environment is too problematic. Instead, people may do best with a more repetitive diet that helps them consistently make healthier choices, even if they might sacrifice some nutritional variety.”

Weekend Tracking and an Unexpected Result

An additional finding showed that participants who reported higher calorie totals on weekends than weekdays also lost more weight. Hagerman explained that this likely reflects more consistent tracking rather than increased food intake, since people often log their meals less reliably on weekends.

Overall, the takeaway is clear. When it comes to weight loss, consistency in eating habits may matter more than dietary variety.