Eating meat: Is it worth it?

Yesterday I was at home eating my meal, when my mother comes and see me throwing a little of the food out. She decided ask me:
 "what is the point of get vegan if you are throwing food out?"

I didn't understand the meaning of that doubt. Maybe just a try of convence me to get out of the veganism, but I wondered for myself:
"how many food do I waste and how many food do a person who eat food waste?"

So I decided to do the math. 

A cow eats about 55 pounds of food everyday and live for 30 months till the 
slaughter. If we make 55 x 30 x 30, we will get the number of 49500 pounds of food. 

After 30 months a cow will reach the weight of 660 pounds, after the 
slaughter just 50% of the weight will be available, so we will have just 330 pounds of food. That means 49170 pounds of food will be wasted. 

A american eat about 273 pounds of meat per year. What is 82% of 330 (the weight of meat we get after throwing out 49500 pounds of food), so per year a american eat just 82% of one cow. If we make 82% of 49500 pounds, we will get the number 40590 pounds, minus 273 pounds (the food we didn't waste) equals 40317 pounds of food throw out! 

Now, a human eat about 4 pounds of food per day, times the whole year, equals 1460 pounds of food. 
So, if I throw out all the food I should eat I were wasting 1460 pounds a year, what means 38857 pounds less than a meat eater! 

I am not a mathematician nor a native english speaker, so maybe the way I expressed myself and the math was not the best, but is a north to see how eat meat is not worth.