Climate change has emerged as a critical global threat, exerting profound stress on food systems and accelerating nutritional insecurities across regions. Rising temperatures, shifting precipitation patterns, soil degradation, and extreme weather events are increasingly disrupting agricultural productivity, diminishing nutrient quality, and destabilizing food supply chains. These changes have intensified the triple burden of malnutrition undernutrition, micronutrient deficiencies, and obesity particularly in vulnerable populations with limited access to affordable, diverse, and nutritious foods. Despite ongoing global efforts, existing food and dietary systems remain ecologically unsustainable, heavily dependent on high-emission production practices, and constrained by socioeconomic and cultural barriers. This study critically examines the intersection of climate stress, food system vulnerabilities, and nutritional challenges, presenting an integrated framework that links environmental pressures with dietary outcomes. Using a comparative and analytical approach, the research identifies the limitations of current strategies and highlights the need for climate-resilient food production, including climate-smart agriculture, crop diversification, technological innovation, and localized circular food systems. The study further outlines pathways toward sustainable human diets that balance nutritional adequacy with environmental stewardship, emphasizing plant-based dietary patterns, biofortified crops, and culturally adaptive nutrition models. The findings underscore that achieving nutritional security under climate stress requires coordinated action across policy, governance, production systems, and consumer behavior. This work contributes to the evolving discourse by proposing strategic, science-driven solutions for building adaptive, nutritious, and sustainable global food futures.