Drinking too much coffee can affect your body throughout the day and even make it harder to fall asleep at night.
From heightened alertness after your first sip to frequent bathroom trips and an afternoon crash, coffee has a distinct effect on your body and brain.
Increasing Alertness
Your morning cup of coffee can leave you feeling pretty buzzed. The effects can be particularly harsh if you drink multiple cups.
“Caffeine can increase heart rate, overstimulate the central nervous system, cause muscle tremors, and increase stomach acid production,” said Samantha Dieras, DCN, RD, CDN, director of ambulatory nutrition services at Mount Sinai Health System.
When consumed in excess, this can result in jitters and anxious feelings, but it helps to eat before drinking coffee, Dieras added.
Frequent Bathroom Trips
Coffee may also affect your bowel movements in the morning, which may be exacerbated if you drink it on an empty stomach.The urge to go often happens in the morning, within a few hours of drinking coffee.
“If you have slower motility or constipation, it can help improve motility and speed things up,” said Rabia De Latour, MD, a gastroenterologist and assistant professor in the department of medicine at NYU Langone Health.
The laxative effect can sometimes lead to diarrhea if you don’t have constipation issues.
You may also have to pee more often. Caffeine signals the pituitary gland to reduce a hormone associated with water absorption in the kidneys, which leads to more urine output.
Midday Slump
The buzz from your morning coffee will likely fade sometime around lunch.
Caffeine boosts energy by blocking a neurotransmitter, called adenosine, from binding to receptors in the brain.
“Once caffeine begins to wear off, the accumulated free adenosine is finally able to bind to its receptors, sometimes triggering a sudden onset of fatigue,” said Stephani Johnson, DCN RD, an adjunct professor of clinical and preventive nutrition sciences at Rutgers University School of Health Professions.
Around this time, you may also notice a headache, as this is a side effect of caffeine withdrawal.You may also experience a low mood, difficulty concentrating, irritability, and not being able to think clearly.
Disrupted Sleep
Caffeine can stay in your system for 10 to 12 hours. If you drink coffee too late in the day, it can disrupt your sleep.
Johnson said a good rule of thumb is to avoid caffeine after 2 p.m. “Consuming caffeine too late in the day can lead to changes in sleep architecture, reducing deep, restorative sleep while increasing lighter, less restorative sleep.”
Not All Coffee Is Created the Same
Not all types of coffee affect your body the same way.
“Coffee varies widely, and I would caution any coffee drinker to know the caffeine content,” DeLatour said.
“Starbucks decaf has more caffeine than most people are aware of, and their regular coffee has more caffeine than certain energy drinks,” she added.
How much coffee you drink and how much caffeine is in your coffee can affect your body in different ways throughout the day.
What This Means For You
Drinking coffee in the morning can affect your body throughout the day, particularly if you drink a lot. Coffee can change bowel habits in the morning, give you a headache in the afternoon, and affect your sleep at night. Be mindful of how much coffee you’re consuming to decrease the chances of negative side effects from caffeine.
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The Impact of Coffee on Your Body: A Comprehensive Look
Understanding Coffee’s Effects
Coffee is a staple morning beverage for many, but its impact extends beyond the initial jolt of energy. A myriad of physiological responses can be triggered by caffeine intake, shaping our day from the moment we take that first sip until we lay down for the night.
Boosting Alertness
The most immediate effect of drinking coffee is heightened alertness. The caffeine found in coffee stimulates the central nervous system and can significantly increase heart rate and the production of stomach acid. As noted by Samantha Dieras, DCN, RD, CDN, this enhanced state of awareness can lead to feelings of anxiousness and jitters, especially with excessive consumption. Eating a meal before drinking coffee can mitigate some of these side effects.
Increased Urination and Digestive Changes
Caffeine also influences bowel movements, particularly when consumed on an empty stomach. For some, like those with slower digestive motility, coffee may help facilitate bowel movements. However, Dr. Rabia De Latour explains that for others, it can induce diarrhea, especially if constipation is not an issue.
Moreover, caffeine prompts the pituitary gland to reduce a hormone that aids water absorption in the kidneys, thereby increasing urine output—a factor that can lead to more frequent bathroom visits.
The Afternoon Slump
As the day progresses, particularly around lunchtime, the energizing effects of coffee begin to wane. Caffeine blocks adenosine, a neurotransmitter that promotes sleepiness; however, once its effects diminish, the accumulated free adenosine can cause sudden fatigue. Stephani Johnson, DCN RD noted that this may also trigger headaches due to caffeine withdrawal symptoms, alongside potential irritability and difficulty in concentrating.
Impact on Sleep Quality
Caffeine’s presence in the body can linger for 10 to 12 hours, meaning that consuming coffee too late in the day may adversely affect sleep quality. Johnson recommends avoiding caffeine intake after 2 p.m. to prevent alterations in sleep architecture, which can result in less deep and restorative sleep.
Caffeine Content Variations
It’s essential to recognize that not all coffee offers the same caffeine content. Dr. De Latour warns that even decaffeinated options, such as those from popular chains like Starbucks, can contain more caffeine than many individuals realize. The intensity of coffee’s effects can vary widely based on the type consumed and the amount ingested.
What This Means For You
Understanding the effects of coffee can help mitigate adverse reactions. Being conscious of your caffeine intake can reduce the risk of experiencing negative side effects such as bowel changes in the morning, afternoon fatigue, and disrupted sleep.
