Adam joins the cross-country team and starts to run several miles every day. Which change would best fit his nutritional needs?

The recommended change of increasing calories and water is particularly suitable for Adam as he takes on the physically demanding activity of running several miles each day. Endurance running significantly raises energy expenditures, requiring athletes to consume more calories to meet their energy needs and sustain their performance.

Additionally, increased water intake is vital for hydration, especially during exercise, as running can lead to significant fluid loss through sweat. Hydration is crucial for maintaining performance, preventing fatigue, and aiding in recovery. Therefore, by increasing both calorie intake to support his energy requirements and water to stay properly hydrated, Adam can enhance his performance and overall health.

The other options do not adequately address the needs of someone who is engaging in intense physical activity. Reducing iron-rich foods could lead to deficiencies, especially since runners require stable iron levels for oxygen transport and energy metabolism. Increasing dairy and soy products does not specifically cater to increased energy and hydration needs, while lowering protein and saturated fats might hinder muscle recovery and overall energy levels, which are essential for an athlete in training.