American diets can provide the required essential nutrients to support health or the means to push an individual closer to disease. However, the rising popularity of weight management medications, such as glucagon-like peptide-1 (GLP-1) receptor agonists, has created multiple obstacles to obtaining nutrients in recommended amounts to support health. Some of the essential nutrients of particular concern are water and associated electrolytes.

Potential Side Effects Affecting Hydration Status

First, one of the side effects of these medications is appetite suppression, which is one of the mechanisms thought to lead to the observed weight loss in clinical trials. This affects hydration as nearly 20% to 30% of water intake in a typical Western diet comes from food. Second, gastrointestinal (GI) side effects are the most common and can include vomiting and diarrhea, which may increase the hydration and electrolyte needs in this population. Third, a relatively unexplored consequence of GLP-1 agonists is reduced calorie consumption and, subsequently, the risk of lean muscle mass loss due to inadequate protein consumption. The challenge is that the combined factors of effective medication administration make it difficult for patients to consume adequate nutrients, including fluids, due to reductions in thirst perception, appetite, calorie intake, cravings, and side effects, such as nausea.

Associated Lifestyle Factors Influencing Hydration

Patients who are prescribed GLP-1 agonists are counseled on the importance of lifestyle modifications, such as engaging in physical activity, to work in tandem with their medication for best outcomes. During physical exercise and exposure to hot weather, sweating is the largest source of water and electrolyte loss (e.g., sodium, potassium, magnesium, chloride), which may further contribute to increased thirst. Additional water losses occur due to respiration, urination, bowel movements, and perspiration. According to the American College of Sports Medicine, hydrating before, during, and after exercise is crucial in preventing dehydration (defined as more than a 2% loss in body weight due to water deficit) and electrolyte imbalances. Fluid loss occurs in both intracellular and extracellular fluid compartments and can potentially reduce plasma volume. An electrolyte imbalance can disrupt normal bodily functions and may lead to symptoms like headaches, fatigue, or even severe conditions such as mental confusion. Electrolyte minerals are also essential for brain function, heart health, and muscle function.

Intake of Carbohydrates in Hydration Status

Finally, these factors, combined with findings that energy intake from carbohydrates increases and protein decreases after semaglutide treatment in patients with type 2 diabetes, underscore the importance of a comprehensive multivitamin, multimineral, dietary, and rehydration protocol to promote nutrient and hydration adequacy in these populations. A diet that is characterized by higher intakes of carbohydrates may contribute to increased hydration requirements based on how the body stores them. When carbohydrates are eaten, the body uses water to store them as glycogen. This may be a contributing factor to why an individual may feel bloated or like they are retaining water after eating bread or pasta dishes. Furthermore, the process of storing carbohydrates as glycogen may increase the feeling of thirst. Drinking water with electrolytes may support hydration needs more efficiently than water alone.

Summary

In conclusion, while GLP-1 agonists offer significant benefits for weight management, their impact on nutrient and hydration status requires careful attention. The combination of appetite and thirst suppression, GI side effects, and altered macronutrient intake can make it challenging for individuals to meet their hydration and electrolyte needs. Additionally, increased carbohydrate consumption may further increase hydration requirements due to the body’s need to store carbohydrates as glycogen. This process utilizes additional water and can contribute to sensations of bloating or water retention, which may make drinking more water more challenging.

Given these factors, it is essential for individuals taking GLP-1 agonist medications to prioritize a balanced intake of fluids — ideally including electrolytes — and to consider comprehensive nutritional support from a qualified health-care practitioner. Although current associations provide a strong rationale for these recommendations, more research is needed in populations using GLP-1 agonists to fully understand and optimize hydration and nutrient strategies for this group. In the meantime, supporting hydration status through mindful dietary and lifestyle choices remains a practical and evidence-informed approach.

To learn more about nutrients, health, and GLP-1:

Nutrient Gaps: 5 Things to Do and Avoid in 2025

The Hidden Effects: Medications and Their Impact on Your GI Tract

Hungry for More: Nutrition Gaps in the Modern American Diet

Electrolytes: Essential Functions for Optimal Health

By Bri Mesenbring, MS, CNS, LDN