If you are eating stupid amounts of meat every meal, sure you might average that high.
And more than that, the food is just CO2, arguably not as bad of a GHG. the petrol/gasoline also has the really bad stuff people don’t bring up as much, such as the nitrogen-oxides and sulfurs.
You burn calories when you exercise
My 30km round trip bike to work burns about ~800 calories, or 1.33 big-mac equivalents, which has a carbon footprint of about 4.2kg CO2
That same round trip would burn 2L gasoline in my car, which has a carbon footprint of about 4.6kg CO2
Edit: I see where you are getting your numbers now after looking around. I will leave my comment here for sake of others seeing it and the discussion.
How are you getting 4.2 kg of CO2 for 800 cal???
The average estimate is 0.35 per 1000 cal for the more eco friendly
https://ourworldindata.org/grapher/ghg-kcal-poore
https://www.globe.gov/explore-science/scientists-blog/archived-posts/sciblog/index.html_p=183.html
If you are eating stupid amounts of meat every meal, sure you might average that high.
And more than that, the food is just CO2, arguably not as bad of a GHG. the petrol/gasoline also has the really bad stuff people don’t bring up as much, such as the nitrogen-oxides and sulfurs.