Listen to your body clock when you eat
“My body runs like clockwork” Sound familiar?
We really do have an internal clock that controls many of the functions our body carries out every day. So far, a biological clock has been identified in the hypothalamus, but it's suspected that we have more in different organs – the liver, lungs, heart and fat tissue – that help this central clock keep “the right time”. This is what we call biological rhythms.
Biological rhythms vary in length according to our body's needs, and they're geared toward achieving maximum biological efficiency.
The best-known and most studied biological rhythm is the circadian rhythm, which lasts between 20 and 28 hours. Circadian rhythms regulate processes such as activity and rest, digestion and metabolism, and hormonal and hematological secretions.
The role of food as an external synchronizer of our biological rhythms has been widely studied. Paying attention to certain aspects of our diet works in our favor and helps our body work better.
What guidelines should we follow to stay in sync with our internal clock?
The first and most important guideline of all is to set regular mealtimes and be fairly strict about them.
Hormone secretion throughout the day also follows clear patterns. In the morning, the hormones that demand energy from us, such as adrenaline, take over, while at night the hormones linked to rest and repair processes appear, such as serotonin and growth hormone. With this in mind, we know that our energy intake should gradually decrease over the course of the day: we should eat more carbohydrates or fats during the day, since they're energy nutrients, and step up our protein intake at night, since protein provides the building blocks for repairing tissue.
We live in a world that never rests, so it's only natural for physiological disorders to appear when our body clock gets out of sync. One factor that has clearly changed our behavior is light. Today, in a world that's always lit up, it's common to have sleep problems and to drag around chronic tiredness and muscle aches from poor rest.
These mismatches between sleep and wakefulness encourage weight gain and hormonal changes that push our body into a state of constant stress, with cortisol being the main hormone involved in this process. A good rest routine is key to keeping our body clock in sync.
Núria Puig – Nutrition and Dietetics graduate, specializing in sports.