The teen and young adult years represent the last major window of opportunity to build bone mass and maximize skeletal strength.
Teens and young adults are in their final window to build strong bones for life. In the second installment of our special series "Stronger Bones at Every Age," we explore how nutrition, physical activity, and lifestyle habits during this critical stage shape lifelong bone health—and how parents and caregivers can support healthy development.
"Stronger Bones at Every Age" is a special limited series made possible in part by the National Cattlemen's Beef Association, a contractor to the Beef Checkoff. This series is dedicated to providing the same evidence-based, unbiased information you've come to expect from the Nutrition Diva, reflecting the editorial integrity and professional expertise of our host.
For more information on the topics discussed in this episode, visit https://www.quickanddirtytips.com/bones.
You can also find citations for the entire series at https://www.quickanddirtytips.com/bones#citations.
Hello I’m Monica Reinagel, host of the Nutrition Diva podcast. Welcome back to our special series on bone health, in observation of Osteoporosis Awareness month. These bonus episodes will publish each Monday in May, and are in addition to our usual Nutrition Diva episodes that publish each Wednesday. The entire series, once complete, will also be available on our website at https://quickanddirtytips.com/bones.
Once again, we are grateful to the National Cattlemen’s Beef Association for helping to make this special series possible. The NCBA is a contractor to the beef checkoff program, a USDA-supervised program that funds research into human nutrition, food safety, environmental impacts, and other topics, and also supports efforts (such as this one) to make that information more widely available. Rest assured, however, that the information I’m sharing in this series reflects my own independent assessment of the evidence, professional experience and judgment.
For any of you who are listening who may be registered dietitians, just a reminder this entire podcast series has been approved by the Commission on Dietetic Registration for 1.5 hours of continuing education credits! At the end of the series, you will be able to access those credits (as well as the episodes themselves) by going to the Beef Nutrition Education Hub at https://beefnutritioneducation.org.
Over the course of the month, we are looking at bone health as it unfolds through the lifespan. In the first episode, we focused on the unique opportunities and challenges to building healthy bones during childhood, looking at diet and nutrition as well as other aspects of lifestyle. And in this episode we’re going to talk about teens and young adults–what is happening in terms of bone metabolism as well as the dramatic shifts in lifestyle that unfold during this dynamic time of life.
By the end of your twenties, your bones are about as strong as they’re ever going to be. That means the teen and young adult years represent the last major window of opportunity to build bone mass and maximize skeletal strength. After this, it’s mostly about maintenance—and minimizing loss.
Puberty is marked by dramatic physical changes, as rising levels of estrogen and testosterone stimulate bone growth and mineralization. Bones not only lengthen but also become denser and structurally stronger. Growth plates—the soft areas near the ends of long bones—are still active in the early teens, gradually closing as adolescence progresses.
Bone development during this period differs somewhat based on sex. Those assigned female at birth tend to accrue bone mass earlier and reach peak bone mass slightly sooner—often in the late teens to early twenties. Those assigned male at birth typically gain more total bone mass, due in part to larger bone size and longer skeletal growth, with peak bone mass often reached a few years later. These differences are driven largely by variations in hormone patterns, growth trajectories, and muscle mass, which exerts mechanical stress on bones.
For adolescents undergoing gender-affirming care, particularly those using hormone therapy or puberty blockers, bone development may be influenced by the type and timing of medical interventions. While this is an area of ongoing research, it's an important consideration for health care providers supporting bone health in transgender and gender-diverse youth.
Regardless of sex, peak bone mass is one of the strongest predictors of your future risk of osteoporosis and fractures. The higher your peak bone mass, the more reserve you have to draw on later in life—especially as bone loss begins to naturally outpace formation with age. While genetics does play a role here, lifestyle choices—especially those related to diet, physical activity, and certain health behaviors—are also critical in determining whether someone reaches their full skeletal potential.
This stage of life comes with its own set of challenges. Teens and young adults often have erratic eating habits, skip meals, or experiment with restrictive diets. They may be physically active—or not. Social pressures, body image concerns, and stress can affect eating, sleeping, and movement patterns. And this is also when substance use—like alcohol, vaping, or smoking—may begin to creep in, all of which can impact bone health.
In other words, this is a time of great opportunity, but also real risk.
As we talked about in the first episode in this series, calcium and protein play intertwining roles in building and maintaining strong bones. Calcium provides the mineral structure, while protein forms the collagen-based matrix that gives bones their flexibility and strength. And during adolescence and early adulthood, the need for both nutrients is at an all-time high.
The RDA for calcium for teenagers is 1300 mg/day, reflecting the fact that their bodies are actively adding bone tissue. More than 50% of teens fail to get the recommended amount of calcium–or of magnesium, and vitamin D, for that matter. This is particularly concerning given how critical these nutrients are for bone mineralization, turnover, and overall structural support.
Dairy products like milk, yogurt, or cheese are good sources of highly absorbable calcium and are usually fortified with vitamin D. Other good calcium sources include calcium-fortified plant milks, tofu, canned fish, collard greens and bok choy.
In terms of protein, most adolescents—especially boys—are meeting or exceeding the Recommended Daily Allowance of about 50 grams per day. However, as many as 1 in 4 adolescent girls are not. And, as we discussed in the previous episode, recent research suggests that the current RDA for protein may not be enough protein to optimize outcomes like muscle development and bone mass accrual.
Intakes in the range of 70 to 90 grams per day may be more beneficial, especially when paired with adequate calcium. Many more teens—particularly girls, and especially those following plant-based or calorie-restricted diets—are falling well short of that higher target.
Some of the foods I just highlighted as good sources of calcium–dairy products, tofu, canned fish–also include a decent amount of protein. And because they generally provide so much more protein per serving, including lean beef, pork, and chicken in the diet can go a long way toward optimizing protein intakes.
Here again is Dr. Taylor Wallace, professor of nutrition at Tufts and George Washington Universities. Dr. Wallace has published a number of papers and reviews of the literature on bone health through the lifespan and has some additional insights to share.
Dr. Wallace: Something that people often underestimate about nutrition and bone health is the important role that complete proteins play in attaining peak bone. Mass protein serves as the glue for bone mineral, and there's a beneficial relationship between higher intake and peak bone mass development. However, not all proteins are created equal. And not all amino acids liberated during bone remodeling can be reused to build new bone. Complete proteins, those usually derived from animal source foods, contain all essential amino acids, which is important so that building bone density and achieving peak bone mass isn't limited by the absence of any one amino acid. Just a f5-10% difference in peak bone mass can result in a 25-50% reduction in hip fractures later in life.
Interestingly, adolescents who include beef in their diets were found to have higher intakes not just of protein, but also of calcium, iron, phosphorus, potassium, choline, zinc, and vitamin B12—all of which support bone health. The broader implication is that nutrient-dense foods—particularly those that provide multiple bone-supportive nutrients—can help close the gap between needs and intakes during this critical developmental stage.
The teen and young adult years have always come with a heightened awareness of body image—as young people become more aware of how their bodies are perceived by others. But today, that self-consciousness is amplified by social media, where curated images and body ideals are constantly on display. Although we often associate these patterns with young women, young men also experience body image concerns—although these may manifest differently, such as pressure to achieve a lean, muscular physique.
Whatever the goal, it's not uncommon for teens and young adults to experiment with dieting or restrictive eating—whether that means cutting calories, eliminating certain food groups, some form of so-called “clean eating,” or skipping meals altogether. Unfortunately, these behaviors can have lasting effects on bone health.
Consuming too few calories—especially alongside high levels of physical activity—can lead to a negative energy balance, where the body isn’t getting enough fuel to support all of its functions. When that happens, the body begins to conserve resources—and one of the systems that gets deprioritized is bone building. Over time, undereating can also interfere with hormone pathways that are essential for bone accrual.
Estrogen, for example, plays a key role in maintaining bone density during adolescence (and beyond). And if young women are under-eating and/or over-exercising, this can eventually suppress estrogen levels so much that they stop menstruating. This can then result in them achieving a lower peak bone mass and then having an increased risk of fractures later in life.
This is so common among young female athletes that it’s often referred to as the “female athlete triad”--insufficient calorie intake, menstrual dysfunction, and decreased bone density. But this isn’t only a concern for athletes—or only for girls. Anyone engaging in restrictive eating is at risk for suboptimal nutrient intake, especially if they’re avoiding entire food groups.
Studies have found that adolescents who consume fewer total calories are more likely to fall short on calcium, vitamin D, iron, zinc, and magnesium—all of which play a role in bone development and maintenance. Restrictive eating, whether it’s driven by aesthetics, athletics, or misinformation, can quietly undermine bone health during this critical window of development.
That said, I want to make an important distinction: While under-fueling can threaten bone development, physical activity itself is not the problem—in fact, it’s part of the solution. Bones respond to mechanical loading, and well-fueled, weight-bearing activity—such as running, jumping, strength training, or even brisk walking—can significantly enhance bone accrual during this life stage. When paired with adequate calorie and nutrient intake, exercise not only strengthens muscles but also sends powerful signals to bones to grow stronger and denser.
So while the combination of intense activity and underfeeding may compromise bone health, well-nourished physical activity is one of the best tools we have to help young people build a strong skeleton for life.
One other threat to bone health that often emerges during this phase of life is the adoption of habits like smoking, vaping, and drinking alcohol. These behaviors typically begin or escalate during the teen and young adult years—just as bones are trying to reach their full genetic potential.
While the occasional drink or puff might seem harmless, these habits can silently undermine a young person’s ability to achieve peak bone mass—raising the risk for fractures and osteoporosis decades down the line.
As you can see, the teen and young adult years represent the final chapter in building the strongest skeleton you’ll ever have. But it’s also a time when nutrition habits can be inconsistent, physical activity may decline or become misaligned with calorie intake, and risky behaviors—like restrictive dieting, smoking, or excessive alcohol use—may begin to take root.
The good news is that bones are still highly responsive during this phase. With the right inputs—calcium, protein, energy, movement, and overall care—young people can maximize their skeletal potential and reduce their risk for fractures and osteoporosis later in life. And for parents, caregivers, coaches, and healthcare providers, this is a prime time to support healthy habits that can truly last a lifetime.
So with that in mind, let’s talk about how we can support teens and young adults—and those who love them—in building strong bones and healthy relationships with food and movement.
Even as teens become more independent, supportive adults can help shape food and lifestyle habits. That might mean keeping protein- and calcium-rich foods on hand, cooking meals together, modeling healthy movement, or simply reinforcing the value of treating your body like it’s going to be around for a long time—because with any luck, it is.
Thanks again to the National Cattlemen’s Beef Association, a contractor to the beef checkoff, for making this special series possible. I hope you’ll tune in next week for the next installment of our special series, where we will be focusing on what’s happening with our bones during midlife, including pre- and post-menopausal periods. You won’t want to miss that one.
If you’re interested in exploring some of the research that I cited today, there is a complete list of scientific references for this series. You can find that at https://quickanddirtytips.com/bones
If you’re a new listener who has joined us for this special series, I hope you’ll also subscribe to our regular weekly podcast, where we take a closer look at the latest nutrition news, research, and trends, sort fact from fiction, and answer your food and nutrition questions!
Nutrition Diva is a Quick and Dirty Tips podcast. Steve Riekeberg is our audio engineer, Brannan Goetschius provides script editing. Holly Hutchings is the Digital Operations Specialist and Morgan Christianson heads up Podcast Operations & Advertising. We also get indispensable support from Nat Hoopes. Thanks to all of them and thanks to you for listening!