In a community with chronically low dietary protein availability, which complex public health outcome would most likely emerge as a consequence of limited nitrogen intake?

A rapid national decline in carbohydrate-related disorders because low protein automatically converts starches into functioning immunological proteins at the population level.

Increased rates of growth retardation and impaired immune response due to reduced synthesis of structural proteins, enzymes, and antibodies that depend on adequate amino acid and nitrogen supply.

Immediate improvements in cognitive performance across the population as the body reallocates nitrogen away from peripheral tissues into the brain irrespective of nutrient availability.

Complete prevention of infectious disease outbreaks because pathogens cannot survive in hosts with low-protein diets, making public health outcomes uniformly better.