Your eyelids are heavy, your dark circles are eating away at your cheeks, and you are sleepy even though the day has barely started. Your first instinct when you wake up: make yourself a strong coffee, just to give yourself a boost for the day. However, that morning shot of caffeine isn’t enough to give you back your energy and you feel like a zombie.
What if it’s because you’re drinking your coffee at the wrong time of day? 20 minutes explains everything to you.
The bad marriage between cortisol and coffee
On Instagram, on many French and Anglo-Saxon well-being accounts of naturopaths, nutrition experts and hormonal balance coaches, publications on the deleterious effects of too high a cortisol level – or stress hormone – are flourishing. And on the false good idea of having coffee first thing in the morning and on an empty stomach.
Among these wellness stars, @healthwithholland, British, hormonal balance advisor who has nearly 775,000 subscribers, describes the signs of too high cortisol levels: “waking up at night, stubborn abdominal fat, cravings for salty foods, feeling like a wreck in the morning and incapacity to fall asleep in the evening, and no appetite when waking up but an irrepressible desire for coffee. There you may be having a revelation about your own condition.
On the same network, the Dr. Lindsey Schmidta doctor with 250,000 subscribers who defines herself as a specialist “in the microbiota, hormones and the nervous system”, drives the point home: “When you finally realize that skipping breakfast and drinking coffee on an empty stomach has unbalanced your cortisol levels and your nervous system and more… Which affected your microbiota, and increased your bloating, your PMS, your anxiety and, strangely, your weight gain.
“Effects on the liver, digestion and the brain”
But how could this simple morning coffee do so much harm? “When you are fasting, coffee firstly has an effect on digestion: it is a fairly aggressive and acidic drink for the stomach, which can create gastric reflux and digestive discomfort,” explains Raphaël Gruman, nutritionist. Then, coffee will have an action on the liver, by slowing down hepatic metabolism and its elimination capacities, which creates additional fatigue: the liver is an organ which already pumps a lot of energy, so if it is overworked , this will further fatigue the body, producing the opposite of the desired boost effect.”
And when it comes to the harmful effects of coffee taken on an empty stomach, the bad points keep coming: “one of the problems with caffeine on an empty stomach is that no food slows down its stimulating effect during digestion. So it passes quickly into the blood, which can cause an acceleration of the heart rate with palpitations, he continues. From then on, this will overstrain the brain, the synapses – the neuronal connections – panic, which generates cerebral fatigue, then general fatigue of the body. The excitement generated by caffeine temporarily masks fatigue, then comes the second Kiss Cool effect where you are even more tired.”
Stress peak, sleep disturbances and weight gain
But what about the impact of caffeine on this famous cortisol level? And what does this have to do with our weight? Naturally produced by the body, cortisol is, as we have said, the stress hormone, but it is also the wake-up hormone. With melatonin, secreted by the body to help you fall asleep, cortisol completes the duo of hormones that regulate our internal clock and the sleep/wake alternation. And it is in the morning, between 6 and 9 a.m., that cortisol levels reach their peak. “While cortisol is necessary, in excess it has deleterious effects on the body: it promotes insulin resistance, which is harmful for diabetics, and promotes weight gain. Consuming coffee on an empty stomach upon waking up prevents the elimination of cortisol, which creates an effect of stress, disrupts the regulation of blood sugar levels and promotes weight gain and fatigue, describes Raphaël Gruman. Hence the importance of giving your body time to lower its cortisol levels.”
We therefore take coffee when we wake up “for its boost effect, but it generates fatigue, encourages repeated coffee intake to finally find that energy that we are looking for so much, which ends up causing sleep disorders and difficulty falling asleep,” continues the nutritionist Yes, the last big loser in this misalliance: our sleep. “Many of my patients have sleep disorders that cause weight problems: we know that short sleepers – less than 6 hours per night – have a 30% additional risk of developing obesity. Coupled with the deleterious action of coffee on sleep, and indirectly on weight, sleep is less restorative and fatigue sets in.”
Coffee yes, but not on an empty stomach
But if, like Brad Pitt, you have a coffee machine with a bean grinder, and the comforting scent of your morning cup is essential to you, you just need to know when and how to drink. “The best time is at least an hour after waking up, when the cortisol level has started to go down, and preferably in the middle of breakfast,” recommends Raphaël Gruman.
And while it is advisable not to drink your coffee too early, you should also not drink it too late: “not after mid-afternoon, because there is about six hours between the moment where you have coffee and when the body has finished excreting this caffeine, he warns. So if you drink it too late, when you go to bed, you risk not getting to sleep.”