Staple ingredients are available to most of the USA's population, including low income populations. Food deserts are real and deplorable, but most Americans who rely on processed foods do so for convenience, not because basic ingredients are inaccessible or too expensive.
Here's a study of how (among other things) longer-acculturated immigrants to the US shift their eating toward convenience foods:
Study results corroborate previous research highlighting the negative impact of acculturation on diet of Latinos. Many mothers described ready access to fresh fruits and vegetables in their native countries, although availability of such foods decreased in the U.S.. Mothers further described how their lives had become increasingly busy and complex, leaving little time for preparing foods, thereby making the allure of convenience foods, often which are unhealthy, more appealing.
This study details the experiences of Latino families. A quick literature skim and anecdata from my own life indicate that it happens with other immigrant groups coming to the US.
Some low-income subgroups of the American population continue to prepare food from scratch. When I was growing up, some of my friends came from low-income fundamentalist Christian families. Fast/convenience foods were a rare treat; the typical meal plan was "find what ingredients are on sale or have good coupons this week, cook meals from them." (Also, stockpile ingredients that keep well at the lowest-cost times of the year. Buy 6 bargain turkeys around Thanksgiving.) This seems to hold regardless of specific belief; I've heard similar stories from friends who grew up in strict Mormon or Orthodox Jewish households.
Later in graduate school I noticed that students also did more of their own cooking than you might expect from their age and income level (ranging from "nonexistent" to "just above poverty line.") I certainly cooked. It would have torpedoed my budget to eat boxed dinners or fast food every day.
Maybe deep religious belief and extended education are also, in different ways, factors that make you less acculturated into the American mainstream. The irreligious recent immigrant from Belarus, the pious Catholic, and the chemistry postdoc may all be less likely to follow the American default dietary practices because they're living further from American defaults to begin with.
Another factor I've noticed is that these low-income households that cook their own meals (and otherwise make long term cost-effective decisions) tend to be low-income but stable-income. If you're on a graduate school stipend or have taken out loans, you don't have a lot of buying power but you're not juggling two jobs or wondering how many hours you'll be scheduled for this week. Likewise, in those low-income religious families where I saw meals planned around costs, they didn't have much buying power per household member but income was steady month-to-month. If you don't have a modicum of stability you can't be sure that "invest in a chest freezer, buy meat in bulk during the best sales" is actually a good financial optimization plan.
Here's a study of how (among other things) longer-acculturated immigrants to the US shift their eating toward convenience foods:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3090681/
Study results corroborate previous research highlighting the negative impact of acculturation on diet of Latinos. Many mothers described ready access to fresh fruits and vegetables in their native countries, although availability of such foods decreased in the U.S.. Mothers further described how their lives had become increasingly busy and complex, leaving little time for preparing foods, thereby making the allure of convenience foods, often which are unhealthy, more appealing.
This study details the experiences of Latino families. A quick literature skim and anecdata from my own life indicate that it happens with other immigrant groups coming to the US.
Some low-income subgroups of the American population continue to prepare food from scratch. When I was growing up, some of my friends came from low-income fundamentalist Christian families. Fast/convenience foods were a rare treat; the typical meal plan was "find what ingredients are on sale or have good coupons this week, cook meals from them." (Also, stockpile ingredients that keep well at the lowest-cost times of the year. Buy 6 bargain turkeys around Thanksgiving.) This seems to hold regardless of specific belief; I've heard similar stories from friends who grew up in strict Mormon or Orthodox Jewish households.
Later in graduate school I noticed that students also did more of their own cooking than you might expect from their age and income level (ranging from "nonexistent" to "just above poverty line.") I certainly cooked. It would have torpedoed my budget to eat boxed dinners or fast food every day.
Maybe deep religious belief and extended education are also, in different ways, factors that make you less acculturated into the American mainstream. The irreligious recent immigrant from Belarus, the pious Catholic, and the chemistry postdoc may all be less likely to follow the American default dietary practices because they're living further from American defaults to begin with.
Another factor I've noticed is that these low-income households that cook their own meals (and otherwise make long term cost-effective decisions) tend to be low-income but stable-income. If you're on a graduate school stipend or have taken out loans, you don't have a lot of buying power but you're not juggling two jobs or wondering how many hours you'll be scheduled for this week. Likewise, in those low-income religious families where I saw meals planned around costs, they didn't have much buying power per household member but income was steady month-to-month. If you don't have a modicum of stability you can't be sure that "invest in a chest freezer, buy meat in bulk during the best sales" is actually a good financial optimization plan.