Should a 13 Year Old Go on a Diet?

Being 13 is an exciting time of life, it’s the first year of being a teen, which can bring plenty of changes. Along with finding the right lifestyle, there are so many popular, trendy, fad diets out there that seem beneficial for a 13 year old’s health. Is going on a diet the right decision, even if weight is a concern? Should a 13-year old go on a diet?

Unless directed by a dietitian or specialized doctor for medical reasons, most 13-year olds don’t need to (and shouldn’t) diet in order to lose weight or eat in a healthy way. Teens can eat enough calories to stay energized while also finding nutrient-dense foods to eat. Supporting healthy habits like getting enough sleep and exercise can also aid proper growth.

The best diet habits for a 13 year-old are to never skip meals (especially breakfast), eat an appropriate amount of calories, drink lots of water, limit soda and processed foods, and choose a balance of foods in correct serving sizes from the food groups. Healthy eating habits are key! 

Read on for all you need to know about healthy 13-year olds and diet tips from a registered dietitian nutritionist. 

Image courtesy of Julia M Cameron via Pexels

Does a 13-year old Need to Diet to Lose Weight and Stay Healthy?

Take it straight from the Academy of Nutrition and Dietetics —  “Maintaining a healthy eating pattern throughout adolescence doesn’t require dieting or complicated meal plans.” During the teen years, 13-year olds can thrive without needing a diet to stay healthy and maintain a healthy weight. 

When it comes to your teen’s health, it is important to understand that diet isn’t the only factor. A registered dietitian nutritionist (RDN) and physician can help guide you through the process of understanding different assessment measures or interpreting weight trends in your teen’s medical history and what changes to make. 

Many adult clients I work with say they started dieting around age 13, and they still aren’t at a healthy weight! That’s because dieting doesn’t work longterm. Developing healthy habits, especially starting at a young age, will help an overweight 13-year old the most for lifelong health.

Dieting can actually increase health risks and overall unhealthy eating habits for a 13-year old. A teenager shouldn’t actively attempt to lose weight unless directed to and closely monitored by a doctor and dietitian. 

Age 13 – From Fad Diets to True Health Habits

What’s the latest fad diet you’ve heard of? Drinking celery juice, gluten-free diet, paleo diet, raw food diet, intermittent fasting? How can 13-year olds spot a fad diet? Often, fad diets require the following without delivering honest results: 

  • Rapid weight loss
  • Unlimited quantities of a specific food
  • Limiting or restricting an entire food (or macronutrient) group
  • Restricting calories
  • Eating specific food combinations 
  • Only eating at specific intervals or time periods during the day
  • Rigid menus or meal plans
  • No exercise involved
  • A specific regimen of supplements or pills
  • Lists of “off-limits” foods
  • Too many “food rules”

Fad diets aren’t a healthy way to lose weight. While fulfilling nutrient needs may not seem as flashy, eating to fuel the body properly leads to health during the teen years. 

Developing healthy eating habits now is the BEST thing a 13-year old can do for lifelong health and weight management. Fad diets only work short term and restricting food just leads to disordered eating habits. Eat smarter and learn to be more mindful to enjoy food for your whole life.

What can a 13 year old do who wants to diet? Keep reading for tips and suggestions.

What Should a 13-year Old Eat?

Eating choices influence how a teen feels physically and mentally. Teaching teens practical tips for choosing healthy foods can help 13-year olds to make the most of their available food choices. 

Here are some foods and food groups to focus on to improve health for 13-year olds:

1. Whole-Grain Foods

Major Nutrients: Carbohydrates, Fiber, B-Vitamins

Carbohydrates, especially those found in whole-grains, provide incredible fuel for growing bodies. In addition to providing nutrients for keeping active, fiber helps smooth digestion. Try eating the following whole-grains to add variety: 

  • Quinoa
  • Whole-wheat couscous
  • Quick-cooking brown rice
  • Oatmeal
  • Popcorn

2. Fruits & Vegetables

Major Nutrients: Vitamins A and C, Potassium, Fiber, and more

Fruits and vegetables don’t have to be boring! Each bite can provide exciting nutrients when prepared in a variety of ways.

Ways to make veggies and fruit more interesting for 13-year olds:

  • Fill half the plate with fruits and vegetables
  • Pack a portion of fruit for lunch
  • Add fruits and vegetables to sandwiches and wraps
  • Try a new flavor or texture
  • Make a fruit or veggie-filled salad
  • Browse the grocery store and choose a fruit or veggie you’ve never tried before
  • Switch up breakfast with some savory vegetables
  • Cook vegetables into a casserole
  • Slice fruit on top of a cereal
  • Make a smoothie with frozen fruit and veggies
  • Cook together
  • Try vegetarian recipes with extra veggies
  • Make a skillet dish with extra food from the fridge

Many teenagers say they don’t like fruits and vegetables, but sit them down with a list and almost everyone can pick 5-10 fruits and vegetables they will eat. Keep favorite items on hand always and try to branch out and try new things as a family. Taste buds change and teenagers will be less picky and more adventurous as they get older.

3. Low-fat Dairy Foods

Major Nutrients: Protein, Calcium, Potassium, Magnesium, Phosphorus

Most adults don’t get enough calcium or potassium. For teens, these minerals are extra important for building strong bodies and bones. Teens should consume at least 3 cups of dairy (or a fortified equivalent) a day — find out more by visiting MyPlate Dairy. Dairy is a powerhouse of nutrients for teenagers in an easy, quick way.

See also: Is it OK for Teens to be Dairy-Free?

4. Lean Protein

Major Nutrients: Protein, Iron, Zinc, and B-Vitamins

The following foods are good sources of nutrients. They also provide a feeling of fullness via vitamins and minerals instead of excessive fats. 

  • Meat 
  • Poultry (i.e. sliced lean turkey)
  • Fish
  • Eggs
  • Beans (i.e. hummus)
  • Nuts (i.e. peanut butter)

See also:

5. Limit Processed Foods and Fast Foods

Not all snack foods and fatty foods are “off-limits” but instead are “sometimes foods”. It’s okay to enjoy a slice of cake or a cookie every once in a while, but probably not every day. Growing teens need to make sure they pack in the nutrients and they don’t have a lot of extra calories in the day for empty calories from foods that aren’t very nutritious.

See also: How Many Grams of Fat Does a 13 Year Old Need Per Day?

Simple Swaps to Help 13-Year Olds Stay Healthy

Studies show that those who are focused on long-term goals instead of losing weight fast actually are more successful at keeping weight off. Healthy habits encourage an ongoing lifestyle that is about long-term changes instead of short-term wants or desires. It often requires simple shifts towards healthy eating day to day as well as enforcing good exercise habits. 

Start today and choose a few simple habits for lifelong health. Here’s some helpful ideas to get you started:

Switch from Sugar-Sweetened Beverages to Healthier Hydration

Regular soft drinks or energy drinks with tons of sugar only provide short-term energy. Fortified drinks such as milk or almond milk can build healthy bones. Other awesome choices include plain water, fruit-infused water, unsweetened tea, or 100% fruit juice. 

See also: Is it OK for Teenagers to Drink Tea? Ask a Dietitian

Try Vegetarian or Plant-based Tastes

The following sources of vegetarian fuel provide plenty of vitamins, minerals, fiber, and nutrients: 

  • Beans
  • Lentils
  • Tofu
  • Tempeh 

Other plant-based options include nut milks or veggie-based pasta. Chains and restaurants often feature these items on the menu — don’t be afraid to try something new! 

See also: Can a 14 Year-Old Go Vegan?

What Is a Healthy Weight Loss Plan for 13-Year Olds?

The best plan for healthy weight loss will differ with each individual. However, there are some general similarities when it comes to making progress.

Spot the Problem Areas

Finding the triggers that make weight gain more likely is the first step to identifying a solution. Some of the common behaviors that prompt putting on weight are: 

  • Skipping meals
  • Eating excessive portions
  • Consuming too many added sugars and solid fats
  • Grazing on high-calorie, nutrient-poor snacks
  • Eating out more than eating at home
  • Eating for emotional reasons instead of following hunger-fullness cues
  • Eating with screens (i.e. phones, television, computers)

Is it Easy to Lose Weight as a Teenager?

Make Small, Significant Shifts

Success happens one small change at a time. Here are some great ideas for 13-year olds to maintain a healthy weight.

How a 13-year Old Can Get to a Healthy Weight:

  • Honor hunger– learn to listen to your hunger and fullness cues.
  • Eat slower– slow down when you are eating to enjoy your food.
  • Limit screen time– Try to get less than 2 hours per day. Turn off screens when eating.
  • Less is more– Indulge on sweets and treats with intention and moderation.
  • Healthy fats– Limit fried foods and opt for healthy fat foods instead.
  • Eat in not out– Try to make meals at home instead of frequently consuming fast food.
  • Don’t restrict food– all foods fit in moderation and balance. Eat a variety of foods.
  • Learn to cook– Help in small ways with meal planning, grocery shopping, and food preparation/cooking at home.
  • Sleep well- Get enough good sleep (typically 8-10 hours per night). Turn off your phone!
  • Enjoyable activity– Start a new exercise routine or join a sports team
  • Control stress. Find ways to relieve stress besides turning to food, such as talking to a friend, going for a walk, journaling, drawing, reading, listening to music, going outside, napping, etc.
  • Water– stay hydrated during the day and drink plenty of water; ditch the sugary beverages and even the sugar-free drinks.
  • Fruits and veggies– Always add fruits and vegetables to meals.
  • Don’t compare– Everyone is different and there isn’t one perfect size, height, hair color, eye color, skin tone, shoe size, etc. Different is good! Everyone is beautiful in their own way. Create a motivational mantra if you need it when you feel down such as “There is just one me, I am enough.” or “I love myself, I am beautiful”.

What stood out to you? Pick one habit to work on this week. Small changes over time make a big difference in the end. 13-year olds who want to lose weight need to eat smarter, not necessarily less.

Check out: What is the Best Diet Plan for a 15 Year-Old? Tips from a Dietitian

Self-Monitor Progress

Tracking positive changes instead of focusing on calories can keep 13-year olds accountable. Teaching teens skills for a healthy life beyond the teen years can help promote positive habits. Weight can fluctuate, but healthy habits can sustain teens through the years. 

See also:

Putting the Pieces Together

Meeting with a nutrition expert, a registered dietitian nutritionist (an RD or RDN), can help 13-year olds to connect the dots in their diet. An RD can identify areas of improvement and even locate potential deficiencies. With all the fad diets that surface during the teen years, dietitians can remain a strength and supportive resource. 

See also: Should Teenagers Take a Multivitamin Supplement?

Don’t Beat Yourself Up

Dietary changes for 13-year olds shouldn’t be about limitations. It’s okay to be spontaneous and flexible, too, from time to time! You can still consume pizza or another favorite food if you want to — try topping it with veggies or adding a side of fruit for a side of nutrient-dense additions. 

Things a 13 Year-Old Should Not Do to Lose Weight:

  • Comparison– Don’t compare your worst to their best on social media. Everyone is unique and everyone loses weight at different rates. Losing weight should be about feeling better, happier, healthier, and more confident, not about looking like someone else or getting to a certain number on the scale.
  • Don’t skip meals– Eat every 4-5 hours. Eat 3 meals and about 1-3 snacks per day.
  • Don’t restrict food– Carbs are okay, dairy is okay, fat is okay, sugar is okay. Even french fries are okay sometimes!
  • No fad diets– All diets work at first and you’ll lose some weight, then you’ll gain back the weight later. This is yo-yo dieting. Those diets aren’t sustainable long-term. Plus fad diets can be really harmful for growing teenagers.
  • No detoxes or cleanse diets- You might feel better after trying these for a few days due to eliminating highly processed and unhealthy foods. You’ll also be restricting other healthy foods and important nutrients and energy your body needs to grow and develop, plus you’ll gain the weight back quickly. Your body is already very good at detoxifying itself, you don’t need to drink celery juice (or something similar) all day to remove toxins.

What about intermittent fasting? See my article: Is Intermittent Fasting Safe for Teenagers? A Dietitian Answers

Should a 13-year old Count Calories?

Counting calories can distract young teens from keeping healthy habits. Calorie needs differ according to the following factors:

  • Age
  • Sex 
  • Activity level

13-year olds should be eating enough calories to not only survive, but thrive! They need calories to perform daily activities. Since 13-year olds are in their peak years of growth, their needs are sometimes higher than other times in life. 

The chart below contains calorie recommendations for 13 year olds. 

Not ActiveModerately ActiveActive
Girls (13 years)1,6002,0002,200
Boys (13 years)2,0002,2002,600

Activity Levels:

  • Not Active – Minimal activity, only moving for tasks needed for daily life, such as walking to the mailbox.
  • Moderately Active – Engages in activity needed for daily living, plus activity equivalent to walking 1.5 to 3 miles daily, or 30 to 40 minutes.
  • Active – Engages in activity needed for daily life, plus activity equivalent to walking 3 or more miles daily, or more than 40 minutes.

Most 13-year olds will fall into the “moderately active” category and need approximately 2,000-2,200 calories each day

Nearly 20% of teens have a body mass index (BMI) that is obese and 3% of teens have an eating disorder. Teens at both ends of the spectrum or anywhere in between can struggle with counting calories. It’s important to help teens self-monitor their progress in healthy ways that aren’t related to fluctuating factors like weight or calories that differ day-to-day. 

See also: Should a Teenager Count Calories? Ask a Dietitian

Tips for Healthy Weight 13-year Olds

Remember, you don’t have to get healthy all on your own! Here are several helpful tips for navigating weight changes during the early teen years.  

Develop a Healthy Body Image

Recent research shows that body dissatisfaction is commonplace for teens. It also suggests that negative outcomes, such as eating disorders, are linked to negative body image. Since nearly 95% of individuals can experience body image issues between adolescence through adulthood, it’s important to address related factors: 

  • Depression
  • Self-esteem
  • Parent communication/care
  • Peer dieting
  • Weight-based teasing

Weight Isn’t the Only Measure of Success

There are many factors that influence weight. For example, an increase in muscle mass could also increase a weight measurement. In a case like this, someone could be becoming more healthy in their exercise habits yet the scale would read a higher number. 

This is why it is crucial to involve trained healthcare providers. Professionals are knowledgeable about interpreting different factors and providing individualized advice based on their assessment and a teen’s weight status trends. 

See also: Will I Get Skinnier After Puberty? and How Can I Tell if my Teen is Overweight?

Involve an Expert

If you think your teenager is experiencing changes in weight due to an underlying root cause, it’s important to bring these concerns to your teen’s healthcare teen. Ask specific questions about what you as a parent and your family can do to help encourage healing and recovery. This can help the professionals identify the cause and develop an appropriate treatment plan to act on. 

Trade Weight Goals for Healthy Habits

Often, the goal for teens isn’t to lose weight but rather to grow into their weight during growth spurts. Weight fluctuates during different stages of life, so the most important thing to do is focus on developing healthy habits and encouraging your teen to maintain an appropriate weight. 

The Bottom Line

Thirteen year olds, and all teens, can get to a healthy weight without dieting. Thirteen is a crucial age for teens to develop healthy habits. If you develop healthy eating habits at age 13, then you’ll never have to go on a crazy diet for the rest of your life. Sticking to a healthy eating plan may not seem like the cool thing to do, but trust me, it’s the smart thing to do! Losing only 1-2 pounds per week is a lot healthier and sustainable than losing a lot of weight fast (spoiler: it will come back!). Remember, no teen should diet or attempt to lose weight unless under careful supervision from a doctor and dietitian.

Want help with meal plans and nutrition from a registered dietitian nutritionist? Check out my meal plans for teen athletes:

Related Questions

Should a 13 Year Old Girl Go On a Diet? No, a teen girl should almost never go on a diet, except for medical reasons and under the supervision of a doctor. Even overweight teen girls should work with a dietitian to develop healthy eating habits that will help them get to a healthy weight instead of suffering on a restrictive diet. Restrictive diets can harm growing teenagers.

Is it Good for a 13-Year Old to Diet? Some 13-year olds need to lose weight, but going on a diet is not good for teens and can cause restrictive eating and unhealthy eating habits that turn into a long life of disordered eating. To lose weight the healthy way, a 13-year old should focus on eating smarter, not just eating less. Eat more fruits, veggies, and whole grains, fill up on protein, never skip meals, get enough sleep, stay hydrated with water, decrease stress, and limit processed and fast foods.

How Can a Girl Lose Belly Fat? Remember that teens are still growing and it’s common to gain weight first before growing taller and slimming out. To lose belly fat, teen girls should focus on adding enjoyable physical activity to their day, fill up on protein and fiber, stay hydrated, eat less processed and fast foods and refined carbohydrates, and enjoy eating more fruits and vegetables.

Is it Normal for a Teen Girl to Eat a Lot? It can be normal for a teen girl to eat a lot, especially before and during a growth spurt. Teenagers need more calories and nutrients than most adults because of the fast growth rate. Don’t stress and check in with a registered dietitian nutritionist if you are concerned about how much your teen is eating. It’s important to plan meals and snacks so your teen isn’t “grazing” and eating all day long.

How Can a 13 Year Old Lose Weight Without Exercise? In order to lose weight without exercise, a 13-year old needs to eat about 300 to 500 fewer calories per day, stay hydrated and drink plenty of water, fill up on protein and fiber at meals, and limit unhealthy fatty and sugary foods. Check with a doctor if weight loss is appropriate trying to lose weight.

What Should a 13-Year Old Eat for Breakfast? Healthy breakfasts for 13-year old teens include healthy carbohydrates (such as whole grains, fruits, veggies, dairy, etc.) and protein (meat, fish, eggs, dairy, beans, lentils, legumes, nuts, seeds). Some of the best breakfast examples for teens include oatmeal with fruit, veggie omelet, breakfast burritos, protein smoothies, Greek yogurt parfait, sliced veggies with hummus, or fruit and cottage cheese.

What Should a 13-Year Old Eat for Snacks? Healthy sncks for 13-year olds include healthy carbohydrates and protein. Some of the best snacks for teens are hummus with veggies and whole-wheat crackers, oatmeal protein balls, whole-wheat toast with nut butter and fruit, salmon or tuna packets with flatbread or pitas, cheese cubes and sliced veggies, a small handful of trail mix, or peanut butter and bananas.

See Also


Ellis E. Healthy Eating for Healthy Teens. Published January 8, 2018. 

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

Ellis E. Nutrition for Growing Bodies. Published May 28, 2020. 

Ellis E. Staying Away from Fad Diets. Published March 18, 2019. 

Frechman R. What a Healthy Weight Loss Plan Really Looks Like. Published June 6, 2018. 

Wang SB, Haynos AF, Wall MM, Chen C, Eisenberg ME, Neumark-Sztainer D. Fifteen-Year Prevalence, Trajectories, and Predictors of Body Dissatisfaction From Adolescence to Middle Adulthood. Clin Psychol Sci. 2019;7(6):1403-1415. doi:10.1177/2167702619859331

Wolfram T. Tips to Help Kids Enjoy Fruits and Veggies. Published May 16, 2018. 

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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