GLP-1 Calorie Calculator
Estimate your TDEE, calorie deficit, protein goals, and daily targets in seconds — optimized for GLP-1 medication users including semaglutide, tirzepatide, and retatrutide.
Fill in the form and click "Calculate" to see your personalized results.
How This Calculator Works
This calculator uses the Mifflin-St Jeor equation, which is considered the most accurate predictive formula for Basal Metabolic Rate (BMR). Your BMR is then multiplied by your activity factor to compute your Total Daily Energy Expenditure (TDEE).
BMR formula (male): 10 × weight (kg) + 6.25 × height (cm) – 5 × age + 5
BMR formula (female): 10 × weight (kg) + 6.25 × height (cm) – 5 × age – 161
The calorie deficit is computed as a percentage of TDEE: Mild (15%), Moderate (25%), or Aggressive (35%). Protein targets are based on 0.7–1.0 g per pound of body weight, which is especially important for preserving lean muscle mass during GLP-1-induced weight loss.
How to Use Calorie Targets on GLP-1 Medications
GLP-1 receptor agonists like semaglutide, tirzepatide, and retatrutide work by mimicking natural incretin hormones. This slows gastric emptying, reduces appetite, and can change food preferences. Many users report feeling satisfied with much smaller portions than before.
Because of this reduced appetite, it becomes critical to optimize the quality of every calorie. Prioritize protein-rich foods at every meal — lean meats, fish, eggs, Greek yogurt, and legumes. Protein helps preserve lean muscle mass during weight loss, supports metabolic rate, and promotes satiety.
Plan 3–5 smaller meals rather than 2–3 large ones. This better aligns with slowed gastric emptying and helps reduce nausea — a common side effect. Start each meal with protein, follow with vegetables, and finish with carbohydrates.
Fiber-rich vegetables (broccoli, spinach, bell peppers) and complex carbohydrates (sweet potatoes, quinoa, oats) deliver essential micronutrients without excessive volume. Avoid calorie-dense but nutrient-poor foods — with reduced appetite, every bite counts.
Track your intake for at least the first 4–6 weeks to build awareness of your new portion sizes and ensure you're meeting protein minimums. Many people on GLP-1 medications inadvertently under-eat, which can lead to muscle loss and fatigue if protein and total calories drop too low.
Why Protein and Hydration Matter
Adequate protein intake is the single most important nutritional factor for GLP-1 medication users. Studies have shown that up to 40% of weight loss during GLP-1 therapy can come from lean mass if protein intake is insufficient. Targeting 0.7–1.0 g of protein per pound of body weight daily significantly reduces this muscle loss.
Hydration is equally critical. GLP-1 medications can cause nausea, vomiting, and diarrhea — all of which increase dehydration risk. Additionally, as you lose weight, your total body water decreases. Aim for at least half your body weight in ounces of water daily, and more if you are active or live in a warm climate.
Spread your fluid intake throughout the day rather than drinking large amounts at once — this better aligns with slowed gastric emptying and helps prevent bloating.
BMR: Mifflin-St Jeor (1990). Mifflin MD, St Jeor ST, et al. Am J Clin Nutr. 51(2):241–247.
Activity Multipliers: Harris-Benedict revised coefficients (Roza & Shizgal, 1984).
Protein Recommendations: American College of Sports Medicine; ISSN position stand on protein and exercise (Jäger et al., 2017).
Hydration Guidelines: National Academies of Sciences, Engineering, and Medicine (2004). Dietary Reference Intakes for Water.
GLP-1-specific adjustments: General nutritional guidance based on published GLP-1 literature and clinical practice. No proprietary formula modification.
Frequently Asked Questions
Common questions about calorie tracking on GLP-1 medications.
A GLP-1 calorie calculator helps users taking GLP-1 receptor agonist medications (like semaglutide, tirzepatide, or retatrutide) estimate their daily calorie needs. It accounts for the appetite-suppressing effects of these medications and emphasizes adequate protein intake to preserve lean muscle mass during weight loss.
GLP-1 medications naturally reduce appetite, so most people eat fewer calories without trying. However, it's important to eat enough — particularly protein — to maintain muscle mass and adequate nutrition. This calculator helps you find a healthy calorie range that supports weight loss without going too low.
Most nutrition guidelines for GLP-1 users recommend 0.7 to 1.0 grams of protein per pound of body weight daily. Higher protein intake helps preserve lean muscle mass during the rapid weight loss that can occur with these medications. Prioritize protein at every meal.
No. This calculator provides general educational estimates based on established formulas (Mifflin-St Jeor equation). It is not a substitute for personalized medical advice from a licensed healthcare provider. Always consult your doctor or registered dietitian before making significant changes to your diet.
BMR (Basal Metabolic Rate) is the number of calories your body needs at complete rest to maintain basic functions like breathing and circulation. TDEE (Total Daily Energy Expenditure) is your BMR multiplied by an activity factor, representing the total calories you burn in a typical day including exercise and daily activities.
Yes. Wegovy is a brand name for semaglutide, and Mounjaro is tirzepatide. This calculator supports both medications. Select the appropriate medication from the dropdown to get tailored nutritional guidance.
GLP-1 medications slow gastric emptying, meaning food stays in your stomach longer. Eating large meals can cause discomfort, nausea, or bloating. Smaller, more frequent meals that are protein-rich help you meet your nutritional targets while minimizing side effects.
The Mifflin-St Jeor equation used here is considered the most accurate predictive equation for estimating BMR in most populations. However, individual metabolism can vary by 10–15%. Use these numbers as a starting point and adjust based on your actual results over 2–4 weeks.
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