Hydration on GLP-1s: The 30/30 Rule
GLP-1 medications like Semaglutide (Ozempic and Wegovy) and Tirzepatide (Mounjaro and Zepbound) are powerful tools for managing blood sugar and weight. However, one of their main mechanisms is slowing down digestion, which can lead to uncomfortable side effects like constipation and dehydration.
Consistent and intentional hydration is essential to manage these symptoms and ensure your comfort. Here's a simple, science-backed approach: the 30/30 Water Rule.
How the 30/30 Rule Works
This rule works with the core biological effects of GLP-1 medications. It’s about timing your water intake to best support your body’s digestive process.
1. Drink 30 minutes before meals: Drink at least 8-10 ounces of water before you eat.
The Science: GLP-1 slows gastric emptying. A meta-analysis of 15 studies found that food stayed in the stomach for about 138 minutes with GLP-1 medications, compared to about 95 minutes with the control group — meaning digestion was slowed by around 36 minutes. Having fluid in your system helps the stomach process food more smoothly when you start eating. This can reduce nausea and discomfort.
Drinking water before meals can help signal satiety, which may reduce overeating, nausea, or discomfort.
2. Drink 30 minutes after meals: Drink another 8-10 ounces of water after you finish eating.
The Science: Enough fluid post-meal is important to soften stool and facilitate passage. Since digestion is slower, the risk of stool becoming dry and hard is higher if hydration is insufficient.
A key tip: avoid chugging water during meals. For individuals with delayed gastric emptying, consuming a large volume of liquid along with food can increase bloating, nausea, or discomfort.
The Role of Electrolytes
If you're still feeling sluggish, fatigued, or experiencing muscle cramps, these may signal an electrolyte imbalance.
Since GLP-1s suppress appetite (and sometimes thirst or fluid intake), and because of slower digestion, electrolytes like sodium, potassium, magnesium, and calcium may not be replaced adequately.
Adding sugar-free electrolyte sources (like LMNT, sugar-free mineral mixes, or high-quality electrolyte water) can help restore lost minerals and significantly improve how you feel.
Final Thoughts
Consistency is key. Following the 30/30 Rule daily is a simple, effective way to support your body, reduce side effects, and improve your weight loss while on GLP-1 medications.
Sources
Smits, M. M., and D. H. van Raalte. “The Effects of Glucagon-like Peptide-1 (GLP-1) Receptor Agonists on Gastric Emptying.” Therapeutic Advances in Endocrinology and Metabolism, vol. 12, 2021, pp. 1–14. SAGE Journals, doi:10.1177/20420188211026042.
Meier, J. J., et al. “Effects of Glucagon-Like Peptide 1 on Gastric Emptying, Glycemia, and Satiety in Type 2 Diabetes: A Meta-Analysis.” Diabetes Care, vol. 38, no. 6, 2015, pp. 1053–1062. doi:10.2337/dc14-2851.
Holst, J. J., and C. F. Deacon. “Is There a Place for Glucagon-Like Peptide 1 in the Treatment of Obesity?” International Journal of Obesity, vol. 39, 2015, pp. 861–867. doi:10.1038/ijo.2015.25.