Ironically, optimizing around cost per calorie is, at least in most places in the US, a great way to have horrible health and die an early death.
When your boss starts pushing Return To Office, ask if the company has a worthwhile kitchen in the office; at least a burner and plenty of room in the refrigerator for ingredients; it should be feasible to cook breakfast and lunch, but also dinner, in case you need to work late.
Essentially nobody is starving in the US for lack of calories (unless it's a case of mental illness or something similar). In fact, in the US, usually the opposite is true. From the Wikipedia page on food insecurity in the US:
> Reliance on food banks has led to a rise in obesity and diabetes within the food insecure community. Many foods in food banks are highly processed and low in nutritional value leading to further health effects. One study showed 33% of American households visiting food pantries had diabetes.