I'm not sure I understand what you're trying to say. Do you think you get energy from some source other than food?

If I burn 100 kilocalories pedaling a bike, my body will be using 100 kcal of energy that I got from food. There is a certain amount of carbon dioxide emission associated with the production of 100 kcal of food. That amount varies with what type of food I eat and what farming practices are used. If I choose to simply not eat extra food to replace the energy I used, my body will simply have less stored energy afterwards. My energy absolutely comes 100%, 1:1 from the food I eat, and that food has an environmental impact.

Now, if I ride an ebike, my body will use less energy. I will use energy generated by the power plant. The energy created at the power plant may actually have less environmental impact than the farm creating the food I would have eaten.