GLP-1 medications (Ozempic, Wegovy, Mounjaro) dramatically reduce appetite and total calorie intake. When eating significantly less, every calorie must work harder — protein becomes the top priority to preserve muscle, which leaves a carefully calculated carbohydrate budget. This tool helps you find that adjusted carb budget based on your calorie goal and protein target.
Calculate Your GLP-1 Carb Budget
Typical on GLP-1: 800-1400 kcal/day. If unsure, use your target from your provider.
How to Use the GLP-1 Carb Tolerance Calculator
When you take a GLP-1 medication, your appetite decreases substantially — many people reduce their calorie intake to 800-1400 kcal/day without trying. This creates a critical nutritional challenge: with fewer total calories available, carbohydrates compete directly with protein for every calorie. Prioritizing protein is essential to prevent muscle loss.
Step 1: Enter Your Daily Calorie Goal
Enter the calorie target you are following on GLP-1 medication. If you haven't set a specific target, use 1000-1200 kcal as a starting estimate for most adults on semaglutide or tirzepatide. Consult your provider for your specific target.
Step 2: Enter Your Body Weight
Your weight is used to calculate the absolute protein target. Supports kilograms and pounds. The calculator converts automatically.
Step 3: Choose Your Protein Level
The minimum recommendation for GLP-1 users is 1.2g of protein per kilogram of body weight. Most nutrition practitioners recommend 1.4-1.6g/kg for active individuals. Higher protein targets leave less room for carbohydrates but better protect muscle mass.
Understanding Your Carb Budget
After allocating calories to protein and essential dietary fat (~0.6g/kg minimum), the remaining calories are available for carbohydrates. If your carb budget comes out very low (under 50g), consider whether your calorie goal and protein target are sustainable and discuss with your provider.
This tool is for informational purposes only and does not constitute medical advice. Consult a qualified healthcare provider for diagnosis, treatment, or any health concerns.
Frequently Asked Questions
Is this GLP-1 carb calculator free?
Yes, completely free with no signup required. All calculations run in your browser.
Is my data private?
Yes. No data is sent to any server. Everything is calculated locally in your browser.
How do GLP-1 medications affect carbohydrate needs?
GLP-1 receptor agonists like semaglutide (Ozempic/Wegovy) reduce appetite and slow gastric emptying, resulting in significantly lower calorie intake. Because total food volume decreases, it becomes more important to prioritize protein to prevent muscle loss, leaving fewer calories available for carbohydrates.
Why is protein prioritized on GLP-1 medications?
Rapid weight loss from GLP-1 medications can cause muscle loss (sarcopenia) if protein intake is insufficient. Most practitioners recommend 1.2-1.6g of protein per kg of body weight to preserve lean mass during the weight loss phase.
Should I consult my doctor before changing my diet on GLP-1?
Yes. Dietary changes while on GLP-1 medications should be discussed with your prescribing physician or a registered dietitian, especially regarding protein targets, micronutrient supplementation, and managing nausea-related food intolerances.
What are the main GLP-1 medications this applies to?
This calculator applies to GLP-1 receptor agonists including semaglutide (Ozempic, Wegovy, Rybelsus), tirzepatide (Mounjaro, Zepbound), liraglutide (Saxenda, Victoza), and dulaglutide (Trulicity). Discuss specific dietary adjustments with your prescribing physician.