We're in an obesity epidemic and most people don't know how to cook even very basic meals.
Make space for it, squish other classes if you need. Make it mandatory, everyone has to take it. Maybe even ongoing through multiple grades.
Edit: Rice, beans, and even basic meats are cheap. To eat healthy you don't need your meal to be 100% Bell peppers and tomatoes.
and what do you think that reason is?
Public school and its education is not as it is advertised. In the US when the government introuced public education, they presented it in a way to let any American have the oppertunity to become well educated and smart and in many ways this is true. However the politicians did not want to give the masses education were they upcoming generation will not be too smart to understand how the world truly works.
School and society as a whole raises you to be the best consumer possible.
Why don’t they teach you to cook, so your likely going to eat out more. Why don’'t they teach you finance, so your likely living by paycheck to paycheck. Oviously teachers are not holding this back from students because they wish to keep their students down. Teachers only focus on following the curriculum.
Also look at how many politicians send their kids to private schools.