1355. Impact of Climate Change on Food Intake, Appetite, and Dietary Choices

Climate change is recognized as a major factor affecting food security in terms of food availability, access, utilization, and stability. The relationship between climate change and food security operates through a cascade of mechanisms that go far beyond mere food availability. Heat stress suppresses appetite through thermoregulatory mechanisms, and climate-induced food insecurity alters the availability and nutritional value of staple crops. This special issue of Appetite brings together studies examining physiological responses, adaptations of vulnerable populations, and sustainable dietary transitions, highlighting the urgent need for climate-resilient food systems and equitable nutrition interventions.

Recent evidence suggests that if the global community does not take immediate action to mitigate and prevent the negative impacts of climate change, the risk of hunger and malnutrition could increase by 20% by 2050. This is particularly concerning given that the impacts of climate change, conflict, and economic disruption have increased the number of people suffering from severe food insecurity from 135 million in 2019 to 345 million in 82 countries by June 2022. The cascading effects extend beyond mere food availability; extreme weather events alter the nutritional composition of staple crops, and rising carbon dioxide concentrations threaten to reduce the protein and micronutrient content of major grains, exacerbating "hidden hunger," affecting billions of people worldwide.

Direct physiological impacts of rising temperatures on human appetite and food consumption are related to thermoregulation and the thermic effect of food. For example, as temperatures rise, the metabolic heat generated by food digestion increases heat stress, leading to adaptive reductions in appetite and food intake. These mechanisms likely evolved as protective responses to prevent the increased metabolic heat load caused by digestion during heat stress, but their impact on people facing prolonged heat exposure has yet to be fully studied.

Climate change also significantly shifts the foods that are available, affordable, and culturally acceptable. In recent years, yields of staple crops such as maize, wheat, and sorghum, as well as fruit trees such as mango, have declined across Africa, widening disparities in food insecurity between countries. The impacts extend beyond yield reductions to food system structures and the resilience of dietary patterns.

Food system transformation requires addressing the structural factors that drive both climate change and malnutrition. Despite accounting for approximately one-third of global greenhouse gas emissions, agricultural policies in many countries continue to subsidize resource-intensive crops and heavily favor industrial livestock farming and biofuels over human nutrition. These subsidies, reinforced by global trade patterns and market concentration, distort prices, entrench monocultures, and limit farmers' and consumers' access to sustainable alternatives. Without addressing these systemic constraints, consumer-focused interventions like ecolabeling and dietary nudges will have limited impact.

Successful interventions often emerge from the ground up, where community-led initiatives integrate local knowledge with scientific evidence. These approaches recognize that food systems are deeply rooted in social, cultural, economic, and ecological contexts. For example, school-based programs combine nutrition education with environmental messages to improve dietary quality and create intergenerational norms. Similarly, nature-based solutions have the potential to deliver up to 37% of the mitigation needed to meet the Paris Agreement goals. However, their effectiveness depends heavily on raising awareness and building capacity within local communities. Programs that focus on the synergies between climate action and nutrition (for example, how improving soil health leads to producing more nutritious crops, or how reducing food waste benefits both households and the global environment) are often more effective than programs that focus solely on the environmental aspects.

Similarly, technology is not a panacea. The success of digital and biotech innovations depends on tailored, inclusive, and equitable strategies that bridge cultural, social, economic, and structural gaps. Combined with community engagement and supportive policy frameworks, these innovations can facilitate climate change adaptation and the transition to healthier diets, rather than becoming a source of new inequalities.

(Reference)
Isaac Cheah, et al. The effects of climate change on food intake, appetite, and dietary choices: From current challenges to future practices, Appetite, Volume 217, 2026, https://doi.org/10.1016/j.appet.2025.108328

Contributor: IIYAMA Miyuki, Information Program