What is Overweight for an 18-Year Old?


Age 18 is a time filled with changes and growth. It is important to recognize the importance of maintaining your health as you gain more independence! 18-year olds should remember that weight is not the sole indicator of health. Lifestyle factors, body composition, genetics all influence health and should be strongly considered. Mental and emotional factors also largely play a role in overall health!

The Center for Disease Control and Prevention (CDC) has created classifications for underweight, normal weight, overweight, and obese. By these classifications, an 18-year old teen is overweight if their body mass index (BMI) is between the 85th and 95th percentiles on the CDC growth charts.

For example, according to the CDC growth charts, for a 5 foot 9 inch tall 18-year old boy, a weight above 175 pounds is considered overweight. For a 5 foot 4 inch tall 18-year old girl, a weight above 149 pounds is considered overweight (at this height). All other factors should be taken into consideration when determining health status.

Read on for more information about how to determine if an 18-year old is at a healthy weight and tips to maintain an appropriate weight.

What is a Healthy Weight for an 18-Year Old?

The CDC defines underweight, normal weight, overweight, and obese using BMI and growth charts. The following chart shows the weight classification that corresponds to each percentile range. 

You can use a growth chart, or the CDC’s BMI Percentile Calculator to determine weight status.

If you have had a doctor or dietitian tell you that your weight was at a certain percentile, this is what they are talking about. However, this is used more as a screening tool and a way of looking at weight trends overtime. There is no need to get fixated on the number on the scale.

As an example. An 18-year old boy that is 5 foot 9 inches tall is considered underweight at 124 pounds and below, 125-174 pounds is considered a healthy weight, 175-195 pounds is considered overweight, and above 196 pounds would be considered obese. At a different height, weight status would be assessed differently.

An 18-year old girl that is 5 foot 4 inches tall is considered underweight at 101 pounds and below, 102-148 pounds is considered a healthy weight, 149-173 would be considered overweight, and above 174 pounds would be considered obese.

Don’t stress too much about weight. Teenagers fluctuate a lot based on growth spurts. Often teenagers gain some weight before growing taller. The pattern over time is more important than one single point on a growth chart. Talk to your doctor or dietitian if you have questions determining health status.

A healthy weight for anyone is a weight that can be maintained without a whole lot of hard effort. If you have to restrict what you are eating in order to stay at a certain weight, it is likely not appropriate for you. A healthy weight is also one that you stay at while you are taking care of your body by giving it nutrient dense foods, water, physical movement, quality sleep, and stress management.

See also:

What Is a Normal Weight for an 18-Year Old?

There isn’t really a “normal” weight for teenagers. The teenage years are full of growth and change and there isn’t one right standard of health and size. Weight status is determined by gender, height, weight, and body composition.

An 18-year old girl that is 5 foot 4 inches tall is considered at a healthy weight between 102 and 148 pounds. An 18-year old boy that is 5 foot 9 inches tall is considered at a healthy weight between 125-174 pounds (between the 5th and 85th percentiles). To check your specific height and weight, check out the CDC’s BMI Percentile Calculator for an estimate.

What Factors Impact Weight?

Weight can be greatly impacted by our eating and exercise habits. Frequent consumption of refined sugars, sugar-sweetened beverages, processed food and fast food are correlated with higher body weight and body fat. Lack of physical activity is also associated with higher weight.

However, eating and exercise habits are not the only factors that influence weight. In fact, genetics is a factor that you have absolutely no control over, but it plays a huge role in determining weight and body composition. 

Stress levels and mental health can also impact weight. In a state of high stress, the body produces more cortisol which can make your body hold on to fat. Emotional eating can also lead to changes in weight. Strong emotions also can cause a lack of appetite for some people, which could also affect weight.

Medical conditions and medications also play a role in weight. For example, thyroid disorders can have a huge impact on your metabolism and therefore, how much energy your body needs. Many medications list weight change as a potential side effect. 

Just remember that many things impact your weight, some of which are out of your control. This is just another reason why weight is not the best indicator of health and also why everyone should treat their body with kindness and respect.

Should an 18-Year Old go on a Diet?

If you are worried about your weight, dieting is not the answer. I promise! While it may seem like a way of getting quick results, dieting does more harm than good. 

Diets almost always include some form of restriction. For example, the ketogenic diet restricts carbohydrates, and intermittent fasting restricts the time window where you can eat. Restriction is not good for the brain or the body. 

Your brain actually tends to have a stronger desire to eat foods that you restrict! If you have ever told yourself not to do something or not to think about something and then only wanted it MORE, this is the same concept! Restrictive eating can lead to intrusive and obsessive thoughts about food which can quickly ruin a healthy relationship with food.

Additionally, cutting out foods can also lead to nutrient deficiencies. Teenagers are especially negatively affected like this because their body needs nutrients to grow and develop. Teen athletes are putting a ton of stress on their body and if they restrict different foods, they will likely not perform as well and can put themselves at a higher risk of injury.

When Should an 18-Year Old Lose Weight?

Purposefully trying to lose weight is not typically recommended for teenagers. If it is recommended by a doctor, seek help from a registered dietitian that focuses more on developing healthy habits and a healthy relationship with food.

Weight loss during the growth years can actually do more harm than good. As you work on developing healthy eating and exercise habits, your body will naturally settle into a weight that is healthy for you. 

How Can Teenagers Practice Body Respect?

Let’s be honest, it can be hard sometimes to love your body! If you have experienced that, try focusing first on body respect. This means finding believable thoughts that bring you into a better state of mind to take care of your body. Some of my favorite thoughts to focus on are:

  • My body is strong 
  • My body keeps me alive
  • My body is resilient
  • My body helps me do the things I love
  • My body has gotten me through hard times 

How Much Should an 18-Year Old Eat?

Energy needs are different every single day. Some days you might be up and moving around while other days you are sitting more. This is why I don’t like giving people an exact calorie goal to aim for. It can sometimes take the focus away from listening to your body and giving it what it needs.

However, it might be a good idea to at least have a general idea of how much a teenager needs to be eating. The chart below shows estimated calorie needs based on gender, age, and physical activity level.

Eating and Exercise Recommendations for a Healthy Weight

Remember that your goals should be focused around establishing healthy eating and exercise patterns rather than on reaching a certain weight. When you do that, your body will naturally get to a healthy weight. Here are some recommendations for healthy habits to begin implementing!

  1. Aim to include a fruit and/or vegetable every time you eat! They provide lots of vitamins, minerals, and fiber, which are essential for a healthy body!
  1. Eat a balance of carbohydrates, protein, and fat at every meal and snack. This will help you feel more satisfied and will keep blood sugars in check throughout the day.
  1. Do not go too long without eating. Your body needs to be continuously fueled throughout the day. You likely need food at least every 4-6 hours. If you let yourself get overly hungry, you are actually more likely to overeat. 
  1. Put away distractions while eating. Stop looking at screens and instead, listen to what your body is trying to tell you.
  1. Tune in to your five senses while you eat. What does the food taste like? What does it smell like? What is the texture on your tongue? Does it look appealing? Can you hear a crunch when you bite into it?
  1. Eat until you feel satisfied. Try and find the moment when your body has had enough and is feeling really good and energized. Sometimes your satisfied point will come sooner than other times and that is okay! Your energy needs are different on a day-to-day and meal-to-meal basis.
  1. Include both strength and cardio exercise in your weekly exercise routine.
  1. If it is challenging for you to exercise, remember that some movement is better than none! Do what you can and build on that.
  1. Find ways of moving your body that you actually enjoy. Maybe that is dancing, skateboarding, playing soccer, jumping on the trampoline, running, swimming, or something else. Mix it up to keep things interesting and fun!
  1. Fuel properly for movement. Do not expect your body to perform at its best if you haven’t given it the fuel to do so. Focus on carbohydrates before exercise, especially the closer you get to an intense workout.

What Else is Important for Maintaining a Healthy Weight?

There are other things that are important to maintaining a healthy weight. Here are a few:

  1. Control stress levels. Find ways of relieving stress that work for you. That could be meditation, exercise, deep breathing, taking a nap, listening to a favorite song, or something else! 
  1. Get enough sleep. Teenagers typically need between 8-10 hours of sleep every night. This helps regulate hormone levels and give your body the time to recover and reset.
  1. Process negative emotions. You will get better at this with practice, but a therapist is usually a great place to start when sorting out some of the emotional baggage that builds up within everyone!

Summary

The bottom line is: teenagers should not be overly concerned about the number on the scale. The way weight is classified based on BMI leaves out many important considerations in evaluating health status. 

Remember that you cannot directly change your weight, but you can directly change your habits. Let that become your focus. It doesn’t mean you have to follow a set of strict rules. Instead, it means respecting, listening to, and taking care of your body the best that you can!

Resources

Centers for Disease Control and Prevention. About Child and Teen BMI. Cdc.gov. Published March 17, 2021.

Centers for Disease Control and Prevention. Sleep in Middle and High School Students. Cdc.gov. Published September 10, 2020.  

Ellis E. How Many Calories Does My Teen Need? Eatright.org. Published October 4, 2019.

Katherine Harmer, RDN

I'm a Registered Dietitian Nutritionist with a love for coaching others to success in their health goals, especially teenage athletes. Tennis was my sport of choice in high school. Now I'm a little bit older, a little bit smarter, and a little bit worse at tennis.

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