The Bone You Have At 50 Was Built Before You Turned 18

Dr. Gabrielle Lyon (0:00)

When we talk about childhood obesity, the entire public conversation is about adipose tissue. How much is there? Where is it? How do I get rid of it? But no one asks what's happening to the skeletal muscle underneath. Adolescence is not a period when bone is maintained, it is a period when bone is acquired. In the four years surrounding peak bone mineral accretion, children lay down close to 40 percent of the total body bone mineral they will ever carry.

Children with obesity are frequently weaker, they have more muscle but not quality tissue. Pediatric researchers have started calling this sarcopenic obesity. A child can have a larger quad and a lower capacity to use it, because bone acquisition is time-limited and the deficit, you don't feel it, it's silent. Fracture arrives without a warning. If you're not training, can you overcome that? I'm not sure.

But now we swap obesity for GLP-1 use and what happens to our children who are growing, both bone and muscle. Here's what the literature points towards.

Lately, I've been getting a lot of questions from my current patients about their kids. Patients are asking me if they should be worried about their kids' weight and or what to do if their kids are a little pudgy. So if you're a parent and you are worried about your child's weight, then listen up for some of my thoughts. Now, I feel like we're at a crossroads. And for the longest time, we've asked the question, what will happen to my child if they lift weights? Instead of asking, what will happen to my child if they don't? Now, imagine a world where in one direction, everyone is in a chair that flies around like in Wall-E, versus, imagine this, a 29-year-old woman steps out of a taxi, sets her foot on the curb, and her weight lands wrong. She hits the pavement. She fractures her hip at 29 years old. Now, nothing on her chart explains it. Her body weight sits in the normal range. She is not on steroids for any kind of lung inflammation. She doesn't have cancer, no metabolic disease. You get the picture. No history that would put a fracture like this anywhere near the differential.

What she has in line with her history from 15 years earlier, when she was a teenager, is she had anorexia nervosa. She got treatment. She recovered. Her weight came back, but her bone did not.

She spent the single window, not intentionally, in which a human skeleton is built, not building, but is built. And the body does not offer that window twice, unfortunately. Now, I want to be very, very careful here because I am not telling you this story to frighten anyone, and I'm not telling it to litigate a disease that is far more complicated than a lecture about nutrition. I am telling it to you because it is the cleanest example that I can think of, and I know of a principle that runs through everything I'm going to say for the next 20 minutes. What a child builds is what an adult gets to spend, especially when it comes to bone. Now, before we get into this episode, if you or someone in your house is in the middle of an eating disorder right now, this episode is not treatment, this is not an eating disorder episode. I'm going to recommend, again, I'm not your physician, but there's a National Alliance for Eating Disorders helpline, and I strongly would consider getting professional help. This is a podcast on childhood obesity. What happens when we go to the extremes like with the GLP-1s? We are seeing this all over Hollywood, but what is the impact of someone who is younger?

Welcome or welcome back. I'm Dr. Gabrielle Lyon, and today we're talking about kids. Now, like I mentioned, I've been getting a version of the same question from my patients in my practice for months now.

It usually comes out sideways in the last two minutes of a visit that was supposed to be about them. It goes something like this. My son is getting soft. My daughter is on medication now. Is it okay if she lifts? Should I say something? Should I say nothing? Underneath every one of those parents' questions is a parent trying to solve for a body they can see, their kid, using tools and tools no one gave them. So let me reframe the whole conversation. For about 30 years, the debate in pediatrics was whether it was safe for a child to lift anything heavier than their own body. That debate is finished. It is done finito. The question that replaced it is the one we need to ask more of. What happens to a child who never builds strength at all? What happens to a child who doesn't lift weights? This is an episode where we're going to go through what a muscle problem looks like in a child, what screens are displacing, and what GLP-1 receptor agonists are doing to muscle and bone in a growing skeleton, and what the training and nutrition response should be. I will hand you a protocol at the end, should you choose to execute it or not. I'm not your doctor, but I'm here to educate. Okay, let's start with a piece that gets missed. When we talk about childhood obesity, the entire public conversation is about adipose tissue, fat tissue. How much is there? Where is it? How do I get rid of it? But no one asks what's happening to the skeletal muscle underneath. Here's what the literature points towards. Children with obesity generally carry more absolute muscle than their normal weight peers. Yes, they do.