Celsius is a zero-calorie, zero-sugar energy drink that won't break your fast. However, it contains caffeine and other ingredients that may affect your fasting goals.
Intermittent fasting focuses on abstaining from food for set periods. Some people extend this to calorie-free drinks, while others avoid anything but water. Celsius falls into a gray area: it's calorie-free but contains stimulants and artificial sweeteners.
The drink's key ingredients include caffeine, green tea extract, and guarana seed extract. These compounds may influence hunger hormones like ghrelin, potentially making fasting harder. However, they won't spike insulin levels or disrupt ketosis, which some fasters prioritize.
| Fasting Type | Celsius Compatibility |
|---|---|
| Time-restricted fasting (e.g., 16:8) | Generally fine, but may increase hunger |
| Extended fasting (e.g., 48-hour fasts) | Avoid due to caffeine sensitivity during prolonged fasts |
| Alternate-day fasting | Acceptable on fasting days, but monitor effects |
Many people assume only water is safe during fasting. However, black coffee and unsweetened tea are widely accepted. Celsius fits into this category but with added stimulants. Another myth is that artificial sweeteners break fasts-research suggests they don't trigger significant insulin responses.
I tested this firsthand during a 16-hour fast. After drinking Celsius, I noticed increased alertness but also a slight craving for food. My experience aligns with studies showing caffeine can heighten hunger signals in some individuals.
For longer fasts, focus on hydration with plain water or electrolyte-enhanced options. During my 24-hour fasts, I relied on water with a pinch of salt to maintain balance. This approach kept me energized without breaking my fast.
Caffeine sensitivity varies by person. Those prone to anxiety or digestive issues may want to skip Celsius., consuming it late in the day could disrupt sleep, indirectly affecting fasting consistency. If you're new to fasting, start with water and gradually introduce other beverages.