Read the full article here.
A few months ago, I began noticing a wellness trend on Instagram that, quite frankly, rocked me to my core. Friends and influencers were waking up, heading to their kitchens, and—gasp of all gasps—not pouring a cup of coffee. Interestingly, they weren’t forgoing their morning caffeine fix altogether, but simply deferring it to a later hour. Which poses the question: When to drink coffee during the day?
A cursory Google search proved confusing, so to cut the stress (which is, coincidentally, what can happen when you drink coffee too early), I tapped a stable of nutritionists—registered dietitian Maya Feller, MS, RD, CDN of Brooklyn-based Maya Feller Nutrition; celebrity chef and nutritionist Serena Poon; and Camille Styles’ own Edie Horstman—to learn more about coffee, cortisol, and circadian rhythms. I even threw in the question all caffeine junkies love: can drinking coffee daily be healthy?
What Is Cortisol?
Before we talk about coffee, let’s talk about cortisol. Often called the “stress hormone,” cortisol is produced by our adrenal glands, and impacts multiple systems throughout the body.
“Along with being responsible for managing your stress response (thus its colloquial name), it also regulates your circadian rhythm which helps your body know when to sleep and awaken,” Poon explains. “Cortisol spikes in the morning when you wake up and ideally wanes throughout the day as you near bedtime. Balanced cortisol levels are important for getting quality, restorative sleep at night.”
Cortisol peaks in the early morning (typically between 8 a.m. and 9 a.m.) then rises and falls throughout the day. When external stressors cause them to spike, our natural energy balance gets thrown off. “Cortisol is affected throughout the day by various stressors and environmental or lifestyle factors,” Horstman adds.
According to Horstman, things that can cause cortisol spikes during the day include:
- sitting inside all day
- eating inflammatory foods
- drinking more than two or three cups of coffee
- a lack of sufficient carbohydrates (particularly in women)
- imbalanced blood sugar

How Does Coffee Affect Cortisol?
Every person responds differently to coffee, but our three nutritionists did agree on one thing: caffeine can cause cortisol to spike a bit, although not nearly as much as something like mental stress. Regular coffee drinkers have also likely developed a tolerance, which decreases the cortisol response over time.
When Is the Best Time to Drink Coffee During the Day?
There does seem to be a recent general rule of thumb that 9:30 a.m. is prime time for drinking coffee, but one specific timestamp does not fit all.
“If drinking coffee at that time makes you feel your best, then go for it!” Poon says. “In my work with clients, we strive to really listen to the messages that their bodies are telling them and find a coffee consumption pattern that best suits their individual needs.”
The nutritionist recommends starting a journal to track how you feel drinking coffee at different times throughout the morning. Log your crashes, how your sleep is affected, and any jittery reactions to find a pattern primed for focus and productivity.