The "Novelty-as-Scarcity" Hypothesis: An Evolutionary Explanation for the Global Obesity Epidemic

The "Novelty-as-Scarcity" (NAS) hypothesis proposes that the consumption of novel foods or foods with non-traditional food component ratios or processing methods is interpreted by the body as a false signal of imminent food scarcity, thereby triggering chronic fat accumulation. This framework is rooted in the evolutionary principle that the ability to store fat was crucial for survival during periods of unpredictable food availability. Today, this may pose an "evolutionary mismatch".Although defining and isolating "novelty" poses methodological challenges, the NAS hypothesis has plausible biological mechanisms, from the initial sensing of novel food components to their metabolic effects that could lead to increased fat accumulation.Observations supporting this hypothesis include weight gain among migrants adopting new dietary habits and rising obesity rates in developing countries with exposure to Westernized foods. The NAS hypothesis implies that standardized dietary recommendations might be suboptimal if they disregard an individual's historical dietary background.