GLP-1 Protein & Water Calculator

Find out how much protein and water to drink daily on Ozempic, Wegovy, semaglutide, Mounjaro, Zepbound, or tirzepatide. Most GLP-1 patients are underestimating both — and the gap is where muscle loss and dehydration happen. Enter your weight to get your personal targets.

Enter your weight above to see your targets.

If you have kidney disease, heart failure, or are on fluid-restricted orders from your physician, follow your provider’s guidance rather than this calculator.

More GLP-1 Tools from Rivas

These calculators were built by the Rivas clinical team for our own patients — and shared freely because the GLP-1 community needed better resources. Protein is one piece of the puzzle.

Why protein targets matter more on GLP-1 medication

GLP-1 medications reduce appetite significantly. That’s the point. But eating less overall makes it easy to under-eat protein — and protein is the one nutrient that protects muscle during weight loss.

When you lose weight, your body draws from both fat and muscle. Resistance training and adequate protein are the two levers that shift that balance toward fat loss. On GLP-1 medications, the calorie reduction happens naturally — but protein intake has to be intentional.

International consensus (2025) recommends distributing protein across 3–4 meals rather than loading it into one meal. Your body can only synthesize a limited amount of protein at a time — spreading it out through the day makes every gram more effective.

Ashley DeLashmutt PA-C, Rivas Hagerstown: “Always start your day with protein. If you’re intermittent fasting, eat something high-protein first — it enables your metabolism to start without immediately triggering carbohydrate metabolism.”
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Common questions

Why is my protein target so high? That’s more than I usually eat. +
Most people eating a standard Western diet get 60–80g of protein per day. The targets from GLP-1 consensus research are higher — typically 100–140g for most adults — because the goal is not just adequacy. It’s preservation of muscle mass during active weight loss. Think of it as a daily floor, not a ceiling. On days you hit it, you’re protecting your metabolism and your long-term results.
Does it matter which GLP-1 medication I’m on? +
No. Protein and water targets are calculated from your body weight and activity level — not from which medication you’re taking. Whether you’re on compounded semaglutide, compounded tirzepatide, Wegovy®, Zepbound®, or any other GLP-1 medication, the muscle-preservation science applies the same way.
Why do water targets change between men and women if they’re not weight-adjusted? +
The IOM Dietary Reference Intakes (the source for these targets) are set at population-level recommendations by sex: 91 oz/day for women, 125 oz/day for men, based on total fluid intake from all sources. About 80% comes from beverages — which is what this calculator shows. Individual needs vary with body size, activity level, climate, and how much food you’re eating (less food = less water from food sources, which is especially relevant on GLP-1 medications).
I’m not hungry enough to eat that much protein. What do I do? +
This is one of the most common challenges on GLP-1 medications — and it’s worth discussing with your provider. A few practical strategies: prioritize protein-first at every meal before vegetables or carbohydrates; use Greek yogurt, cottage cheese, eggs, or protein shakes to hit targets without large volumes of food; and track for one week to see where the gaps actually are. If appetite suppression is making it difficult to meet nutritional minimums, your provider may adjust your dose or titration schedule.
Should my protein target go down as I lose weight? +
Yes — but it’s more nuanced than just tracking scale weight. The research base is lean body mass (LBM), not total weight. As you lose weight, you want to lose fat while keeping as much muscle as possible. Using your InBody scan results at each Rivas visit gives us your actual lean mass — so the protein calculation is based on muscle, not the fat you’re actively losing. That’s why recalculating at visits matters, especially in the first 6–12 months.
Why does drinking water before meals help with weight loss? +
A 2010 study from Virginia Tech (Davy et al., published in Obesity) found that adults on a calorie-restricted diet who drank 500ml (~2 cups) of water before each meal lost significantly more weight over 12 weeks than those on diet alone. The mechanism is straightforward — water increases stomach volume and activates stretch receptors that signal fullness. On GLP-1 medications, your appetite is already suppressed — drinking water before meals reinforces that signal and helps prevent unintentional overeating in those early weeks when food sounds good even if hunger is reduced.
How much protein should I eat on Ozempic? +
The target is the same regardless of which GLP-1 medication you’re on: 1.2–1.6 grams of protein per kilogram of body weight per day, distributed across meals. For most adults on Ozempic, that works out to 100–160g per day depending on weight and activity level. Enter your weight above to get your specific number. The reason this matters more on Ozempic is that the medication suppresses appetite significantly — making it easy to eat less of everything, including protein.
How much protein should I eat on Wegovy? +
Wegovy (semaglutide) and Ozempic contain the same active ingredient and work through the same mechanism. The protein recommendation is identical: 1.2–1.6 g/kg/day to preserve muscle mass during weight loss. Because Wegovy is dosed specifically for weight loss (often at higher doses than Ozempic), appetite suppression can be more pronounced — which makes hitting daily protein targets even more important and more challenging.
How much protein should I eat on Mounjaro or Zepbound? +
Mounjaro and Zepbound both contain tirzepatide and tend to produce stronger appetite suppression than semaglutide-based medications in many patients. The protein target is the same — 1.2–1.6 g/kg/day — but the challenge of hitting it can be greater. If you find yourself unable to eat enough to reach your protein target, that’s worth discussing with your provider. It may indicate that your dose is suppressing appetite more than is clinically ideal.
Why am I getting headaches and feeling tired on semaglutide? +
Headaches and fatigue are among the most common early signs of dehydration on GLP-1 medications. When appetite decreases, food intake drops — and 20–30% of daily water typically comes from food. That hidden water source disappears before most patients realize it. Constipation is another early signal. If you’re experiencing these symptoms, increasing your water intake is the first thing to address — aim for the target shown in the calculator above and prioritize water before each meal.
References [1] Rubin KH et al. Protein recommendations for GLP-1 receptor agonist therapy — international consensus. ScienceDirect. 2025. Protein >1.2 g/kg/day distributed across meals preserves lean mass during GLP-1 therapy.
[2] Institute of Medicine. Dietary Reference Intakes for Water, Potassium, Sodium, Chloride, and Sulfate. National Academies Press; 2005. Total fluid: 91 oz/day women, 125 oz/day men.
[3] Davy BM et al. Water consumption reduces energy intake at a breakfast meal in obese older adults. Obesity. 2010;18(3):523–525. PMID: 19661958
[4] Almandoz JP et al. Nutritional considerations with antiobesity medications. Obesity (Silver Spring). 2024;32(9):1613–1631. doi:10.1002/oby.24067
Medically reviewed by Eli Luft, PA-C · Updated March 2026
Rivas Medical Weight Loss — 34 years of physician-led weight management across Maryland, Virginia, and Florida. Protein targets based on international GLP-1 consensus research (ScienceDirect 2025). Water targets based on IOM Dietary Reference Intakes.