Feuling Perfomance Starts With Sleep

Why Sleep May Be the Missing Link in Your Nutrition Strategy

When athletes think about improving performance, nutrition is often at the forefront—macros, meal timing, hydration, supplements, etc. But there’s a critical piece of the puzzle that doesn’t come on a plate: sleep.

According to a 2025 Sports Science Exchange article by Joanna Fong-Isariyawongse, MD, and Kim Schwabenbauer, DHSc, RD, CSSD, sleep is not just recovery time—it is a powerful regulator of appetite, metabolism, and body composition. In fact, poor sleep can quietly sabotage even the most well-designed nutrition plan.

“Sleep remains an often-overlooked factor that profoundly influences dietary regulation, metabolic function, and body composition.”—Fong-Isariyawongse & Schwabenbauer, Sports Science Exchange (2025)

Sleep and Hunger: A Hormonal Tug-of-War

Sleep plays a major role in regulating two key appetite hormones: ghrelin (which increases hunger) and leptin (which signals fullness). When sleep is restricted, ghrelin rises, and leptin falls—essentially telling the body to eat more while feeling less satisfied. Even one night of insufficient sleep can trigger hormonal changes that increase hunger and cravings for calorie-dense foods. This explains why athletes who are underslept often struggle with late-night snacking, poor food choices, and a constant feeling of hunger—even when calorie intake hasn’t changed.

Why Sleep Loss Drives Cravings

Sleep deprivation doesn’t just affect hormones—it changes how the brain responds to food. Research shows that lack of sleep increases activity in the brain’s reward centers while weakening the areas responsible for impulse control.

In simple terms, high-calorie foods become more tempting, and willpower becomes harder to access.

1% increase in ultra-processed food = .04kg decrease in lean body mass (Viola et al 2020)

For athletes trying to follow structured fueling plans or manage body composition, this neurological shift can make consistency feel nearly impossible. And reaching for ultra-processed foods can lead to a decrease in lean muscle mass (Viola et al., 2020).

Metabolism, Blood Sugar, and Performance

Short sleep duration also impairs glucose metabolism and insulin sensitivity, meaning the body becomes less efficient at using carbohydrates for fuel. The article highlights that even brief periods of sleep restriction can reduce glucose uptake and increase fat storage.

While athletes often have better metabolic flexibility than non-athletes, they are not immune.

The takeaway? Cutting carbs to “fix” sleep deprivation isn’t the answer. Instead, sleep quality should be treated as a foundational performance strategy, alongside training and nutrition.

Cortisol: The Hidden Cost of Poor Sleep

Sleep loss is also linked to elevated cortisol, the body’s primary stress hormone. Chronically high cortisol promotes fat storage—especially around the abdomen—and interferes with muscle repair and growth.

“Persistently high cortisol levels can hinder recovery, slow lean mass development, and increase the risk of injury.”

For athletes pushing hard in training, inadequate sleep can quietly shift the body into a more catabolic (breakdown) state, increasing injury risk and slowing progress.

Student Athletes: A High-Risk Group

Student athletes are especially vulnerable to acute and overuse injuries due to early school start times, academic pressure, evening practices, and screen use. Nearly three-quarters of U.S. high school students report inadequate sleep on school nights.

“Optimizing sleep should be considered a foundational pillar, alongside nutrition and training, for achieving peak performance and long-term athletic success.”

For young athletes, sleep is not optional—it supports growth, recovery, emotional resilience, and long-term health.

Nutrition Strategies That Support Sleep

Rather than relying on supplements, a sports nutrition coach advocates a food-first approach to sleep support. Evidence-backed options include:

• Tart cherry juice for melatonin support

• Tryptophan-rich foods (turkey, dairy, oats, quinoa) to aid serotonin and melatonin production

• Kiwifruit, shown to improve sleep quality and recovery metrics in athletes

Caffeine timing also matters. While caffeine can enhance performance, late-day use may significantly delay sleep onset and reduce sleep quality.

The Bottom Line

Sleep is not a luxury—it is a performance tool.

When sleep is compromised, hunger increases, cravings intensify, metabolism suffers, cortisol rises, and recovery slows. No amount of perfect nutrition can fully offset these effects.

“For athletes at every level, sleep is not a luxury; it is a foundational tool for reaching performance, body composition, and health goals.”

If we truly want to help athletes fuel, move, and grow, sleep must be part of the conversation.

By working with a sports professional, you can help your adolescent athlete grow in body, mind, and spirit. This will keep them on the field.

Source:Fong-Isariyawongse, J., & Schwabenbauer, K. (2025). Fueling Performance Starts With Sleep: How Sleep Loss Undermines Nutritional Goals. Sports Science Exchange, Vol. 38, No. 268.