The Ultimate Fasting Safe-List
The most common question in the intermittent fasting community is without a doubt: “Can I have [Food/Drink] during my fasting window?” The rules of fasting depend entirely on your goals (autophagy vs. weight loss), but generally, anything that provokes an insulin response or contains significant calories will break a fast. Use our instant search engine below to check your favorite drinks!
☕ Does It Break My Fast?
Type a drink or food below to instantly find out if it breaks a fast.
The Golden Rules of Fasting Liquids
To ensure you don’t accidentally kick yourself out of ketosis or halt autophagy, stick to these fundamental guidelines during your fasting window:
1. Water is Your Best Friend
Plain water, sparkling water, and mineral water are 100% safe. In fact, you should increase your water intake while fasting, as you are no longer getting hydration from food. Adding a pinch of Himalayan pink salt can help replenish lost electrolytes.
2. Black Coffee and Plain Tea
Black coffee contains virtually zero calories and does not spike insulin. Even better, studies suggest caffeine can actually stimulate lipolysis (fat burning) and increase the rate of autophagy. Plain green tea and black tea are equally excellent choices.
3. Beware of “Zero Calorie” Sweeteners
Artificial sweeteners (like aspartame or sucralose) might have zero calories, but studies show they can still provoke a cephalic phase insulin response (your brain tastes sweet and prepares for sugar). Natural sweeteners like Stevia and Erythritol are generally safer, but strict fasters avoid them to completely reset their sweet cravings.
4. The “Under 50 Calories” Myth
Many people believe that consuming under 50 calories (like a splash of milk in coffee) will not break a fast. While a tiny amount of heavy cream won’t completely halt fat burning or kick you out of ketosis, the protein and lactose in milk will immediately shut down autophagy. If your goal is longevity, keep it strictly zero calories.
