Can You Drink Coffee While Intermittent Fasting? Impact on Weight Loss

Intermittent fasting has gained popularity as a way to lose weight and improve your health (both in the short term and long term). But what about that morning cup of coffee we all crave to boost our energy and focus? Can you drink coffee while intermittent fasting? 

To find out, we spoke with César Lara, MD, Owner of César A. Lara Center for Weight Management. He shares more on how coffee interacts with this popular dietary approach, the potential benefits and drawbacks and guidelines for enjoying it responsibly. 

What is intermittent fasting?

Intermittent fasting is a dietary pattern that cycles between periods of eating and fasting. Unlike traditional diets that focus on what you eat, intermittent fasting emphasizes when you eat. By restricting food intake to specific fasting windows, this approach can help with weight loss, improve insulin sensitivity (which may reduce type 2 diabetes risk) and enhance cellular repair processes.

One popular eating pattern is the 16/8 method, where you fast for 16 hours and enjoy an eating window of eight hours. Oftentimes this is achieved by skipping breakfast and not eating anything after dinner in order to tap into the benefits of intermittent fasting.

Another approach is the 5:2 diet, involving five regular eating days and two days of significantly reduced calorie intake. (This makes intermittent fasting effective for weight loss). But questions remain about incorporating specific foods and beverages, like coffee, into this lifestyle.

Can you drink coffee while intermittent fasting?

The short answer is that black coffee typically doesn’t break fast. “If you're going to drink coffee, it has to be black,” Dr. Lara says. “It cannot be with any other substances that contain calories.” Black coffee is essentially calorie-free and doesn’t trigger an insulin response. 

Insulin is a hormone that helps your body store glucose for energy. By avoiding foods and drinks that stimulate insulin production, you can promote fat burning and other benefits associated with intermittent fasting. 

The benefits of drinking coffee while intermittent fasting

Beyond not disrupting your fast, coffee might even offer some advantages. “Coffee definitely is a stimulant,” explains Dr. Lara. “Sometimes it helps brain function, it helps in giving us a little bit of energy and helping us begin to move around.” 

Another reason to consider drinking coffee while fasting? Caffeine, the active compound in coffee, can also improve focus and temporarily suppress appetite. These effects can be particularly helpful during fasting periods when you might experience hunger or fatigue. 

Adding ingredients to your coffee affects intermittent fasting

So, what happens if you want to add other ingredients to your cup? According to Dr. Lara, “if you’re putting cream on it or putting other substances in it, be aware that is breaking the fast.” Milk, cream, sugar or flavored syrups can introduce calories, thereby defeating your fasting goals. Even artificial sweeteners can stimulate insulin release in some individuals. 

“Intermittent fasting works specifically by decreasing the glucose, which then subsequently decreases the insulin, which then sends the SOS signals to the mitochondria to self-destroy so they can regenerate,” Dr. Lara explains further. By adding calories through additional coffee ingredients, “you're no longer lowering the glucose.” For optimal fasting results, stick to black coffee. However, if you find black coffee too bitter, you can add a bit of cinnamon or a couple drops of stevia. This helps balance flavors without adding calories. 

How much coffee can you drink while intermittent fasting?

While black coffee is generally considered fasting-friendly, moderation is key. Dr. Lara recommends “no more than one or two cups a day in the morning.” 

Dr. Lara warns that excessive caffeine intake while intermittent fasting can have unwanted effects. “Because you're making your body be a little more stimulated to the point of stressing it, then the body could begin to produce sugar itself.” This is called gluconeogenesis, a metabolic process in the liver and kidneys that produces glucose, especially to meet the body's needs between meals. 

The result of drinking too much coffee lies in your fasting goals. “Sometimes you're not going to have the same effectiveness in intermittent fasting as you would if you were more moderate with your use,” says Dr. Lara. 

More on the health benefits of coffee: 

Does the Coffee Loophole Really Help with Weight Loss? Top Nutrition Experts Weigh in

Is Mushroom Coffee the Key to Stress-Free? Experts Weigh In on the Trendy Brew

Dr. Bob Arnot: Drinking This Dunkin’ or McDonald’s Coffee Helps Boost Weight Loss

This content is not a substitute for professional medical advice or diagnosis. Always consult your physician before pursuing any treatment plan.