Seasonal changes in our metabolism and behavior

With the arrival of new seasons there are bodily changes such as in body weight or in mood. But, why?

Seasonal variations in our metabolism and behavior occurred because we have to adapt to these annual environmental fluctuations such as changes in ambience, temperature or light. A mind and body for every season? It’s a fact.

For the last 200 years we have lived in environments with constant heating and light, so it was expected that these seasonal variations would have little influence. But they have.


Our body metabolism and our mood are subject to circadian changes that occurred around the day-night cycle. 

These changes depend on the circadian ‘master clock’ all of us have in our brains that synchronizes all other clocks in our body organs: the hour we wake up in the morning or the best moment of the day to metabolize the food we eat depends on this circadian master clock.


There are also changes called ultra-circadian, larger than the circadian or 24 hours. 

One of these changes is the seasonal ones because our biological rhythms are synchronized with the season of the year: our activity and metabolism depends on climate factors or the duration of the solar day and sunrise and sunset time.

There are seasonal variations in blood pressure and blood cholesterol, higher in winter than in summer. There is also a seasonal trend of cardiovascular diseases with the highest incidence during winter. And these seasonal changes are independent of the climate of the country: the only thing that matters is the season.

Some of these changes may be linked to shifts in body weigh, because in the fall people fell hungrier and eat larger meals -especially carbohydrates- than during summer.

Seasonal rhythmicity of food intake persists in humans even with modern lighting and heating, which are though to shift our circadian rhythms. The seasonal influence on eating is strongly linked to a survival mechanism that probably acts by suppressing satiety.

3cb29413dfc9ffbcff453b8ef42d27dbSeasonality also affects our behavior: cognitive performance or mood.

Some people undergo deterioration in mood in the winter mainly due to seasonal changes in length of day-night and amount of light that mediates shifts in our brain chemistry.

Annual rhythmicity also influences our cognitive performance. In summertime some people are more alert and attentive than in the winter, whereas around the autumn our working memory is stronger than in the spring.

Now that autumn and winter are around… watch your business!

Cover photo: Diego Anciano / @collagevintage2 _Streetstyle London Fashion Week