Following the latest fad diet, buying fat burner supplements, or squeezing into shapewear are just several of the desperate attempts by many weight-loss hopefuls. For weight loss management, dieters should look no further than the days of the week on their calendars. According to a recent study published in the journal Obesity Facts, typically, dieters are more likely to lose weight on Tuesdays and gain weight on Saturdays.

The seven-day cycle of a week is known to have more of an environmental and behavioral, rather than biological, impact. The days of the week can determine sleeping patterns, physical activity, and even eating habits. Social circumstances give meals meaning, as they influence food intake and the eating behavior of people directly or indirectly, consciously, or subconsciously, says the European Food Information Council. When people eat with family and friends, the quantity of food increases as the number of diners grow. Increased social facilitation, especially during the weekends, leads to an increase in caloric intake and meal sizes, compared to weekdays.

A team of researchers sought to investigate whether weight fluctuation was dependent on the days of the week by examining this pattern across three groups of people: those who maintain their weight, gain weight, and lose weight. The researchers also used self-recorded weight measurements from four previous studies of 80 participants between 25 to 62 years old.

The volunteers were instructed to self-monitor and record their daily weight immediately after waking up and before breakfast. Only weight measurements that were taken over at least seven consecutive days were included in the study. The minimum follow-up period was between 15 days to a maximum of 330 days.

The findings revealed a clear pattern in weekly weight fluctuation with the highest weight after weekends — Sunday and Monday — and the lowest weight on Fridays. However, to the researchers’ surprise, there was a difference between weight losers and weight gainers in these fluctuation patterns. Weight losers had stronger compensation patterns — experienced weight loss immediately after the weekend until Friday — while minimum and maximum weights were not seen among weight gainers. This group had more variability between days and no definite decrease during weekdays.

Overall, this study found daily weight increases begin on Saturday and the decreases begin on Tuesday, especially for those who lost or maintained their weight. These results highlight that there is a clear weekly rhythm to weight variation. The authors found “…weight variations between weekdays and weekends should be considered normal instead of weight gain. On the weekends people have more time to go out and eat. Some indulging during weekends makes no harm but for successful weight loss it is important to notice these rhythms and take steps to reverse the upward trends after the weekend, even if it has to wait until Monday.”

In a similar study published in the journal Obesity, researchers found a group of healthy adults consistently gained weight on weekend days, but not on weekdays. This finding was attributed to higher dietary intake on Saturdays and lower physical activity on Sundays compared to weekdays. The change in lifestyle behaviors from weekdays to weekends contribute to weight gain or a stop in weight loss. This helps explain the slow rates of weight loss and the difficulty in maintaining it.

Despite the findings of both studies, daily fluctuations in body weight are common because of changes in hydration status, dietary intake, and physical activity patterns. Nutrition intake and meal patterns, and body weight, tend to vary during Thanksgiving weekend, the holidays between Thanksgiving and early January, and between different seasons of the year. Weekend eating patterns also influence weight control in the short- and long-term. In order for successful weight control to happen, dieters should notice these weight rhythms to reverse weekend weight gain. A less strict diet and short-term splurges will help dieters feel better and more in control about their bodies.

Sources:

Ermes M, Korhonen I, Mattila E, Orsama AL, van Gils M, and Wansink B. Weight Rhythms: Weight Increases during Weekends and Decreases during Weekdays. Obesity Facts. 2014.

Holloszy JO, Obert KA, Racette SB, Schechtman KB, Steger-May K, Villareal DT. Influence of Weekend Lifestyle Patterns on Body Weight. Obesity. 2008.