Intermittent fasting involves periods of eating and not eating. A common question is what can be consumed during the fasting window without interrupting the fasted state. This often leads to scrutiny of beverages like Propel Water. Understanding whether Propel Water breaks a fast requires examining its ingredients and how different definitions of “breaking a fast” apply.
Propel Water’s Composition
Propel Water is a flavored water beverage designed for hydration. It contains water, citric acid, natural flavors, salt, and vitamins (C, E, B3, B5, B6). Propel Water is advertised as having zero calories and zero sugar. To achieve its sweet taste, it uses artificial sweeteners, primarily sucralose and acesulfame potassium (Ace-K). It also includes electrolytes like sodium and potassium, which are calorie-free minerals intended to replenish those lost through sweat.
Defining a Fast and Its Interruption
In intermittent fasting, “breaking a fast” means consuming anything that causes the body to exit its fasted state. The strictest definition considers any caloric intake, no matter how small, as breaking a fast. This is because consuming calories signals the digestive system to activate, potentially shifting the body out of a state where it primarily burns stored fat for energy.
Beyond caloric intake, the body’s insulin response is another important factor. A significant insulin spike can halt fat burning and other metabolic processes associated with fasting. Some fasting protocols also emphasize autophagy, a cellular repair process. Autophagy is optimized when glucose and insulin levels are low, and calorie intake is restricted.
Impact of Propel’s Ingredients on Fasting
Propel Water’s zero-calorie and zero-sugar content means it generally does not break a fast based on caloric intake alone. The electrolytes in Propel, such as sodium and potassium, also do not contain calories and are acceptable during a fast. These minerals are often beneficial to replenish, especially during longer fasts, to prevent imbalances like muscle cramps or headaches.
The main debate concerns Propel Water’s artificial sweeteners: sucralose and acesulfame potassium. Some studies suggest sucralose might not affect blood glucose or insulin levels acutely. However, other research indicates sucralose can lead to increased insulin levels in some individuals, potentially by triggering sweet taste receptors. Some studies also suggest artificial sweeteners might alter gut bacteria or impact insulin sensitivity over time. Acesulfame potassium has also been identified as a potential “insulin kicker.”
Aligning Propel with Your Fasting Goals
The decision to consume Propel Water during a fast depends on individual fasting objectives. For those whose primary goal is weight loss through calorie restriction, Propel’s zero-calorie nature makes it permissible. It can help maintain hydration and electrolyte balance without adding calories.
However, for individuals pursuing stricter fasting benefits, such as maximizing cellular autophagy or achieving optimal insulin sensitivity, avoiding artificial sweeteners might be a more cautious approach. The potential for artificial sweeteners to elicit an insulin response, even if small, or to influence gut health, could interfere with these specific goals. If your fasting aims include gut rest or cellular repair, it might be beneficial to avoid all artificial sweeteners.