Weight rhythm confirms the importance of healthy everyday food choices
VTT Technical Research Centre of Finland, in collaboration with Cornell
University and Tampere University of Technology, has studied how people's
weight fluctuates over the seven days of the week. A clear weekly rhythm was
found, with weight highest after the weekend and decreasing trend during
weekdays. A surprising find arose when weekly fluctuation was studied among
different weight management groups. Although there was a weekend weight gain
across all groups, differences emerged in the weekday rhythm of weight gainers
and weight losers.
For all groups – gainers, losers and maintainers – weight was highest on
Sunday and Monday, after which weight began to decrease. The groups diverged
as a result of different weight fluctuation pattern during weekdays. For the
groups losing and maintaining weight, the decreasing trend in weight began on
Tuesday and continued downward until Friday. The week's minimum weight was
most frequently observed on Friday or Saturday. Weekday weight loss in the
group of weight gainers lacked linearity, with minimum weight distributed
across all days of the week.
The results indicate that weight losers succeed in compensating during the
week for the slight weight increase gained during weekend.
"Weight gain following a weekend can be thought of as normal weight variation.
Some indulging during weekends and gaining a bit of weight isn't harmful from
the weight management point of view as long as this is compensated by healthy
food choices during the week. It is important to notice these rhythms and take
steps to reverse the upward trend after weekend," says VTT research scientist Anna-Leena
Weight loss and weight management is a question of lifelong change. More
flexible food choices, unburdened by multiple constraints, are easier to
assimilate and maintain over the longer term. Successful weight management
emphasises a long-term energy balance that is unaffected by short-term weight
The results are based on self-measurement data collected in four earlier VTT
research projects in which subjects had been instructed to monitor and record
their daily weight. Researchers analysed the weight development of 80 people
aged 25–62 years on the basis of results for daily early morning weight. The
minimum monitoring period was 15 days, and the maximum 330 days.
Advances in technology have brought various applications and devices available
for self-monitoring of health and vital functions. The researchers aim to
utilize the new data obtained without the steering influence of the
authorities. These data contain valuable information on people's daily
behaviour that could bring discovery of phenomena unobtainable using
traditional research designs.
Reference: Orsama, A., Mattila, E., Ermes, M., van Gils, M., Wansink, B., &
Korhonen, I., (2013). Weight rhythms: Weight increases during weekends and
decreases during weekdays. Obesity Facts, Forthcoming. http://www.karger.com/Article/FullText/356147
For the weight gainers (right), weight increased during the weekend, but no
linearly decreasing trend was during weekdays. Among weight losers (left),
after the gain during weekend the increase started immediately and continued
downward until Friday.