Everyone has slightly different sleep patterns, but we all agree: Mondays are the worst. Turns out, as you drag yourself out of bed, you’re dragging a little extra weight that you didn’t have last Friday. Don’t worry though — these weekly fluctuations seem to be normal, says medical writer Peter Janiszewski at PLOS' Obesity Panecea blog.
A quick examination of typical weekend habits indicates exactly how this happens: We tend to eat larger, more calorie-rich meals on the weekend (fries and beer, anyone?), and lounge around resting. The results of our week vs. weekend habits are stark — just take a look at this data from fitness-tracker wearers in cities around the world.
A study this year dove into exactly how these patterns influence our weight. A research team looked at self-reported weight measurements in 80 adults and analyzed the day-to-day differences according to the day of the week. Sunday and Mondays brought in the highest weight scores, and Friday’s mornings weight in brought the lowest, they reported in the journal Obesity Facts. "Everybody's weight follows a predictable weekly rhythm," they write in a statement. "You gain a little bit over the weekend and lose a little bit over the week."
Janiszewski writes that people’s tendency to "cheat" on their diets over the weekend might also contribute to this. But he adds:
Evidence seems to favor such a flexible approach to diet management, by contrast to the all or none approach. The former approach allows you to enjoy some highly-favored but potentially calorie-dense foods in relative moderation, potentially increasing long-term adherence to a diet. By contrast, the latter approach, which outright forbids certain foods, may result in dietary boredom, and complete discontinuation of the healthy diet.
The study authors agree. "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," study author Brian Wansink of Cornell University told CNN's The Chart.