Chapter 16: Adult Nutrition

Energy requirements are determined through quantitative assessment methods including Estimated Energy Requirements and Basal Metabolic Rate calculations, which form the foundation for individualized nutrition planning. Macronutrient recommendations operate within the Acceptable Macronutrient Distribution Ranges framework, though current population-level data reveal widespread overconsumption of saturated fatty acids, added sugars, and sodium—disparities addressed in national health objectives like Healthy People 2030. The chapter emphasizes a comprehensive total diet approach using evidence-based tools such as the Dietary Guidelines for Americans and MyPlate model, which prioritize dietary variety, nutrient density, and balanced consumption patterns across time rather than focusing on isolated foods. Fiber intake receives particular attention due to its demonstrated protective effects against metabolic dysfunction and chronic disease risk, with attention to both viscous and fermentable fiber types and their mechanisms of action. Fluid balance and hydration are discussed within the context of thirst mechanisms and the contribution of caffeine-containing beverages to overall fluid consumption. Physical activity emerges as a critical component of adult health promotion, with recommendations targeting 150 minutes weekly of moderate-intensity aerobic exercise or 75 minutes of vigorous-intensity activity, supplemented by resistance training for muscular strength and improved metabolic outcomes. The chapter concludes by examining multilevel nutritional intervention strategies, ranging from individual-level behavioral modification and counseling through community-level social support systems to population-level policy interventions including mandatory nutrient fortification programs and economic measures such as taxation of sugar-sweetened beverages to shape dietary environments and reduce chronic disease burden.