How to use this: Pick a scenario button at the top to get started. Then slide the controls in the cards below to match what you really eat in a week: how many servings of beef, chicken, cheese, rice, fruit and so on. Everything updates right away. The big green tile shows the greenhouse gas (kg CO2e) your food causes in a year, and the other tiles show the water and farmland behind it, plus the money wasted on food that gets thrown away. Look at the “One meal a week” chart to see which single swap helps the most. When you’re done, copy the link at the bottom to save your diet or share it with your class.
kg CO2e per year saved if you change just one weekly serving (or one habit) from where your sliders are right now.
kg CO2e per person per year by food group, typical US diet vs. your scenario.
Move any lever. Each change is ranked here by the kg CO2e per year it saves.
The link below encodes every slider. Anyone who opens it sees exactly this diet.
Interaction pattern inspired by En-ROADS, created by Climate Interactive and MIT Sloan. Companion to the other wann.org simulators (carbon, water, energy, transportation, waste). Independent model, not affiliated with any agency or company.
Everything runs in your browser. For each food group: servings per week × grams per serving ÷ 1000 × factor per kg × 52. Servings are what you buy, including the food that ends up in the trash; the waste slider multiplies everything by (1 − 0.30) ÷ (1 − your waste share), so it equals 1 at the 30% typical and rises or falls from there. Meals eaten out add a little on top. Factors are life-cycle averages for each food from farm to store; they are almost the same wherever you live, which is why the region picker only changes the tap-water comparison.
The Food & Diet Simulator estimates the carbon, land and water footprint of what your household eats in a year, plus the food you throw away. Shift servings between beef, chicken, beans, dairy and plants, cut food waste, and see how each change compares.
Food footprints use the Poore & Nemecek (2018) global food lifecycle dataset, shown through Our World in Data. Water footprints use Mekonnen & Hoekstra’s Water Footprint Network research. Food waste figures use ReFED’s U.S. Food Waste Report, diet guidance references the EAT-Lancet Commission, and U.S. diet data uses USDA ERS. Results are estimates for learning and planning.
Key sources:
Beef and lamb are usually highest per kilogram, followed by cheese. Beans, grains and most vegetables are far lower.
Less than most people think. Our World in Data shows that what you eat matters far more than how far it traveled, because transport is a small share of most foods’ footprint.
ReFED estimates that a large share of U.S. food goes unsold or uneaten, and homes are the single biggest source of that waste.
No. Swapping a few beef meals a week for chicken, beans or vegetables and wasting less food can make a noticeable cut.
See all Food & Kitchen guides →
Built and reviewed by the Accessible Sustainability Alliance, a 501(c)(3) nonprofit operated by the Wann Heritage Foundation. Last updated October 5, 2026. Results are estimates for education and planning. Questions or corrections: contact@wann.org.