What Happens if You Work Out Regularly But Don’t Eat Enough Calories?

Most athletes strive for peak performance through training and nutrition. Calories from food are an important part of training for success. Calories are what the body uses for energy and energy is required for muscles to move and exercise. Teenagers need to eat enough calories to fuel their bodies for sports. With this in mind, teen athletes should practice caution when making any diet changes that include restriction of food.

What exactly will happen if you work out regularly, but don’t eat enough calories?

If a teen athlete does not eat enough and still works out, performance will ultimately suffer. The body will not have the energy to meet the demands of the sport and will experience decreased muscle and tissue repair. The athlete will feel dizzy, fatigue early, and may even lose interest in experiences that require more energy, such as training. Long term lack of adequate food and calories will cause muscle wasting, damage to organs, poor hormone function and stunted growth. Not eating enough will really hurt your physical abilities.

Continue to read for more information regarding how not eating enough calories will impact an athlete and how to identify when an athlete does not consume enough calories.

The Dangers of Not Eating Enough for Athletes

When the teenage body is well fed, it can perform incredible feats. However, when there is a lack of food for the body to use as energy, the body will focus on survival over all other activities. This survival tactic means less energy for training and performance.

What Happens to Your Body When You Don’t Eat Enough:

Low energy
Early fatigue
Poor muscle recovery

Poor athletic performance
Muscle loss and wasting
Heart and brain problems

Poor health
Frequent injuries
Hormone dysfunction

Bone loss
Stunted growth

In the short term, athletes will rapidly run out of energy due to a low storage of fuel for their bodies. This energy depletion means early fatigue, which never works well for sports.

Due to under eating, the athlete may also not consume enough protein and carbohydrate for muscle recovery, putting future performance at risk. The body needs protein, carbohydrate, and fat to build and replenish muscle and energy.

When an athlete continues to not eat enough and train hard, the consequences become even more serious. Long lasting insufficient calorie intake puts the entire body at risk.

The body needs energy from food to keep the heart beating and the body systems working. So, when less energy is available from food, the body begins to convert muscle protein into necessary energy. This protein conversion along with lack of protein for recovery leads to muscle loss and wasting.

Other essential components of a healthy body will also suffer from the lack of calories. The heart and other organs will begin to suffer causing further negative consequences to health and performance. The body will do all it can to save energy for these essential body systems. With all energy going towards basic survival, teen athletes may lose their passion for the sport. The energy required to move and participate in a sport may become a chore rather than an enjoyment. They may also experience hormone dysfunction, bone loss, and stunted growth as the body fights to survive and diverts resources away from these functions.

Signs You Are Not Eating Enough Before A Workout

Early signs of not eating enough before a workout are hunger pains and the feeling of an empty stomach. Few enjoy working out with a full stomach, but an empty stomach does not help either. There’s a happy medium or being fueled and energized, without digestion problems.

Other signs to watch for include feeling like more effort is necessary for the same results, tiring quickly, obsessive thoughts of food, lightheaded and dizzy. With repeated lack of calories before workouts, athletes will also experience frequent injury and sickness, lack of enjoyment with sport, and amenorrhea (loss of period for girls).

Not eating enough calories before a workout can happen easily. The calorie demands of growth and development during the teenage years along with the additional calorie needs of training can make eating enough of a challenge. Many teenage athletes may not realize they are not eating enough until they notice the signs of undernutrition. However, both female and male teenage athletes are at risk for eating disorders and should seek professional help with signs of an eating disorder. These signs can include secrecy around eating, obsessive thoughts about food and weight, drastic weight changes, and rigid rules around eating and food.

If there are concerns of an eating disorder, the National Eating Disorders Association provides a screening tool at nationaleatingdisorders.org. The helpline is (800) 931-2237.

Female Athlete Triad

Female athletes who work out without eating enough calories can develop a serious condition called the female athlete triad. This triad is where inadequate calories lead to a disruption of hormones causing a loss of menstruation (period cycles) and low bone mineral density. The lack of calories can happen unintentionally or through disordered eating habits.

This loss of a period (amenorrhea) comes from the body no longer producing an appropriate balance of hormones as it conserves energy for survival. The imbalance of hormones includes a decrease in estrogen. Low estrogen combined with inadequate minerals, such as calcium, from food result in low bone mineral density.

Poor bone mineral density puts a female athlete at high risk for osteoporosis. Osteoporosis is a debilitating disease of weak bones. Those with osteoporosis experience an increase in bone fractures and a decrease in mobility as they age.

Sometimes an athlete will be told that the lack of a period is normal in very active females.The lack of a period is not normal and causes lasting damage. An athlete experiencing this issue should seek the advice of a medical professional.

Tips for Pre-Workout Fueling if You Don’t Like Working Out on a Full Stomach

Finding the right timing for eating before a workout may require some experimentation. Usually, the recommended time is to eat 1 to 3 hours before a workout, no closer than 30 minutes before. An athlete can shift their meal or snack time 30 minutes closer to race time if their stomach feels too empty or 30 minutes earlier if the stomach feels too full during the work out. Eventually the athlete will find the timing that works best for them. Experiment on practice days to know what timing works by competition.

If an athlete chooses to work out on an empty stomach in the morning, emphasis should be placed on a good recovery meal after a workout. This meal should contain a mix of carbohydrate and protein to replenish what was lost. The athlete will also want to make sure they eat enough to meet their calorie needs during the rest of the day. Hydration should never be skipped, even in the morning. Dehydration will negatively impact performance and health.

Another helpful tip for an athlete who prefers an empty stomach before a workout is to eat a balanced meal 3-4 hours prior to the workout. These hours after the meal gives the body time to digest the food. This meal should contain a mix of fat, protein and carbohydrate to help sugar levels maintain stable for long lasting energy. If needed, a lighter snack can be eaten closer to the workout.

Examples of Meals 3-4 Hours Before a Workout Include:

Pasta with chicken and veggies
PB&J sandwich

Greek yogurt parfait
Waffle with nut butter and fruit
Rice cakes with hummus (depending on personal tolerance)

Bagel sandwich
Cottage cheese and fruit slices
Cold cereal and milk

Tuna pouch with pita crackers
Rice with curry and veggies
Veggie pita pocket

Examples of Snacks 1-2 Hours Before a Workout Include:

Fruit smoothie
Energy bar and fruit
Trail mix and dried fruit

Toast with nut butter and a banana
String cheese and crackers
Hard boiled egg and juice

Pretzels and peanut butter
Fruit leather
Dates

Teen athletes will have unique needs and preferences. They should find what works best for them before an event. Athletes should not make changes to eating patterns in the days prior to an actual event as these changes could lead to stomach distress. Nutrition should be a part of training and a focus during the season.

See also:

The 25 BEST Pre-Workout Meals and Snacks For a Teenage Athlete

The BEST Post-Workout Snacks for Teenagers – Dietitian Recommended!

What Does Eating Enough Calories While Regularly Working Out Look Like?

Each athlete will enjoy a different pattern of eating before a workout. One athlete may prefer a meal 2-3 hours before working out and another may choose to eat lighter snacks closer to training time. The most important principle in ensuring that a teen athlete will have the energy needed to perform, is the overall intake. In other words, is the athlete consuming enough calories throughout the day and weeks to meet energy and growth demands?

Teenage athlete needs can vary from 2,000 to 2,800 calories depending on sex, age, weight, height, and activity level. Rather than trying to hit a certain number of calories, an athlete can focus on other indicators such as feelings of fullness, hunger, and overall wellness. Teen athletes typically need about 3 meals per day with 1-3 snacks that are “mini-meals” and provide necessary nutrients and energy.

The Bottom Line

When an athlete eats enough calories while regularly working out, they will avoid experiencing the consequences of not having enough energy. They will have energy to train and perform well. They will also be in a better position to fight off sickness and avoid injury, build muscle and strength, and enjoy participating in their sport.