-Hormone disruption from the lack of useable amino acids and 'bad cholesterol' from which your body cannot properly create/maintain cellular function (immune system, endocrine system, gene expression.) Alternatively, with healthy fats and saturated fats from unprocessed red meat, including the good balance of proper amino acids, for instance, your body can create the required hormones more efficiently and in proper form. Your endocrine system (HPTA axis) is incredibly important (and sensitive to disruption) to so many aspects in your body and controls the basic cellular function in any mammalian being. Huge contributor to neurodevelopment, mood and subsequently mental health.
-Hormone disruption from pesticides commonly used in todays farming (especially mega-farms specific to producing for these restaurant chains/grocers.) I encourage you to do your research on these specifically.
-Microflora, more specifically good gut health, is incredibly important in mood regulation and neurodevelopment. Your gut is commonly referred to in the medical world as the second brain -- over 90% of serotonin alone is produced and stored in your guts.
Good day.