Here's How Nutrition, Sleep and Exercise Are Connected

Nutrition and sleep go "hand in hand," according to Caroline Susie, R.D., a licensed dietitian in Dallas and official spokesperson for the Academy of Nutrition and Dietetics.

"Nutrition and good sleep make for happy people," Susie said, adding that a deficiency in either leads to brain fog, fatigue and "just not being our best selves."

For instance, a lack of sleep can impact the production of hormones.

"In particular, levels of the hormone that tells us we're full—leptin—drops," Susie explained. "And the hormone that tells us we're hungry—ghrelin—increases."

Sleep deprivation or insomnia can increase the release of the stress hormone cortisol during the day, added Mareya Ibrahim, a chef and cookbook author based in California. Those "out of whack hormones" can cause people to overeat, she said.

"Getting your seven to eight hours as an adult helps you to manage your hormones and subsequently manage stress in your body, as well as manage your hunger and register when you're actually full from eating," she said.

For better snoozing, dietary changes can help, nutritionists agree. They provided some tips for better zzzs:

Balance is key

"Having a certain balance of fats, protein and carbohydrates can help calm the brain," said Sally K. Norton, M.P.H., a nutritionist and author in Richmond, Virginia. On the other hand, an excess of sugar or alcohol can make it harder for the brain to "settle down."

Get plenty of fiber

Ibrahim recommended ensuring your diet has plenty of fiber, which has been linked to deeper, more restorative sleep, among numerous other benefits. She also mentioned brown and black rice and leafy greens as fiber-rich foods, adding that the hydrating aspect of leafy greens helps to combat inflammation.

Choose foods that contain melatonin and tryptophan

Near bedtime, Susie suggested favoring foods that contain melatonin, a hormone that plays a role in the sleep-wake cycle.

"Foods that contain melatonin include eggs, fish and cereal," she said.

Susie also recommended foods that are a good source of tryptophan.

"Tryptophan is an amino acid, and research has suggested that it helps you fall asleep faster and sleep longer," she said.

Tryptophan is most notably found in turkey but is also present in chicken, fish, eggs, milk, beans and pumpkin seeds.

Time your meals right

Susie advised that meal timing is very important, too.

"You don't want to go to bed immediately after a large, high-fat meal. On the flip side, you don't want to go to bed on an empty stomach, because that can keep you up as well," she said.

Stop drinking caffeinated drinks early

With caffeine, Susie noted that the general recommendation is to cease consumption by midday if you're on a typical daytime routine.

Coffee isn't the only culprit, either. Caffeinated teas, energy drinks and soda can all interfere with you falling asleep, she said.

Just as your car can't run without gas, your body can't run properly with an energy deficit, Susie explained.

"When I say energy, I'm talking about the macronutrients carbohydrates, protein and fat," she added.

Your body needs these nutrients in large amounts to function optimally.

Just as nutrition fuels physical activity, exercise can impact the way we eat. Connection studies have found exercising could alter our feelings about foods, reducing appetites and curbing our cravings for fatty, calorie-dense foods.

If you want more energy, stamina and muscle growth, it'll come as no surprise that nutrition can help. Here's what our experts recommend:

Consider the type of athletic activity

The best foods to eat to improve physical performance may vary on the type of activity you're doing, Norton advised.

"If you're a high-level athlete, you're going to need more carbohydrates than someone who's just trying to get fit," she added.

No matter what activity, adequate protein is key, Ibrahim noted.

"I recommend that people seek to get at least half a gram of protein per desired body weight pounds," she said. "If you're trying to build muscle, the recommendation is more like 1 to 1.25 grams per pound of body weight."

For example: If you weigh 150 pounds, you want to get at least 75 grams of protein every day, or 150 grams if you're trying to build muscle mass, she explained.

Time your meals

Susie noted that it's not only what you eat that matters. Just like sleep, when you eat is also important.

"Before exercising, you need to allow two to three hours of digestion time for smaller meals or three to four hours of digestion time for larger meals," she advised. "If you're doing an endurance sport, you should eat a carbohydrate-based snack 30 minutes beforehand to provide an energy burst."

Hydrate

"Adequate hydration is essential for metabolic function," Susie noted. "Dehydration can lead to mistaken hunger cues and cause cramps, joint pain, dry mouth, headaches and fatigue, in addition to decreased performance, increased recovery time and soreness."

Drinking water and sports drinks can obviously help you stay hydrated, she added, but so can a lot of foods.

"Fruits and vegetables, including bananas, spinach and cantaloupe, as well as yogurt, have high water content," Susie said. "In addition to being hydrating, they can help with cramping."

The formula for health—sleep, exercise and nutrition—sounds straightforward, but adopting lifelong habits can be challenging. If you're struggling to eat fewer processed foods, sleep eight hours and hit the gym five days a week, know that you're not alone.

Remember, good habits take time, so allow yourself some grace. Small changes—such as switching your daily soda to sparkling water and taking the stairs at work—are easier to maintain and may gradually build to powerful transformations in overall fitness, sleep quality and nutrition.