Do Hip Bones Keep Growing? Separating Fact from Fiction

September 30, 2025 •

4 min read

Contrary to the common belief that our skeleton stops growing in our late teens, studies using CT scans have shown that pelvic bones can continue to grow wider well into a person's 70s. The surprising truth about whether hip bones keep growing reveals a fascinating aspect of the aging process that affects our body shape and waist circumference over time.

Quick Summary

Explore the scientific evidence confirming that hip bones, or the pelvis, continue to widen throughout adulthood, even after height growth ceases. Understand how this natural skeletal change contributes to changes in waist size and overall body shape as we age.

Key Points

Pelvic Widening: Studies show that the pelvis, or hip bones, can continue to widen throughout adulthood, even after height growth ceases.
Beyond Fat: This gradual widening is due to actual bone growth and remodeling, not just fat accumulation, although body fat also plays a role in appearance.
Skeletal Maturity: Most skeletal growth for height stops around age 20, but the bones of the hip continue to undergo a different type of growth.
Waistline Impact: The increase in pelvic width can contribute to a larger waist circumference as individuals age.
Genetics and Lifestyle: While bone structure is largely genetic, lifestyle factors like diet and weight-bearing exercise can influence muscle and fat distribution around the hips and maintain bone density.
Distinction from Osteoporosis: Adult widening is a natural aging process and is different from the bone density loss and weakening associated with osteoporosis.
Bone Remodeling: The ongoing change in adult bones is a continuous process of bone breakdown and renewal, which is distinct from the endochondral ossification of childhood.

The Surprising Reality of Adult Skeletal Growth

While most people stop growing in height by their late teens or early twenties, a widespread misconception persists that all skeletal growth ceases at this point. However, research has provided surprising evidence that certain parts of the skeleton, particularly the bones of the pelvis (the "hip bones"), continue to change and expand over a person's lifetime. A study published in the Journal of Orthopaedic Research analyzed CT scans from adults between the ages of 20 and 79 and found that the width of the pelvis consistently increased with age. On average, the pelvic width of the oldest participants was nearly an inch larger than the youngest, a change that can lead to a noticeable increase in waist size. This means that the widening of your hips as you get older isn't solely due to changes in body fat; your underlying bone structure is also a contributing factor.

What Drives Pelvic Widening in Adulthood?

This adult-onset pelvic widening is a different process from the bone formation that occurs during childhood and adolescence. During the younger years, long bones grow in length via growth plates in a process called endochondral ossification. These growth plates fuse and close around skeletal maturity, typically in the mid-twenties, which halts further height increase. The ongoing widening of the pelvis in adulthood is instead a result of continuous bone remodeling—a lifelong process where old bone tissue is broken down and new tissue is formed. This widening is an example of true pelvic growth and not just appositional bone formation, which would have a different effect on the pelvic structure.

Growth vs. Remodeling

It is important to distinguish between the two primary mechanisms of bone change to understand why hip bones can widen in adulthood while height remains stable. The difference is best explained by considering the role of growth plates and the overall process of bone turnover.

Childhood Growth (Ossification):

Primary Mechanism: Endochondral ossification, where cartilage models are replaced by bone, primarily at growth plates.
Typical Outcome: Increases in both height and bone width.
Growth Plate Status: Active during childhood and puberty, responsible for longitudinal bone growth.
Main Driver: Hormones like growth hormone and sex hormones.
Effect on Waist: Generally smaller waist proportionate to growing body frame.

Adult Change (Remodeling):

Primary Mechanism: Lifelong bone remodeling—the continuous breakdown and renewal of bone tissue.
Typical Outcome: Widening of the pelvis and other skeletal areas, but no increase in height.
Growth Plate Status: Fused by skeletal maturity (mid-20s), so no more longitudinal growth occurs.
Main Driver: Combination of aging, hormonal shifts, and long-term mechanical stress.
Effect on Waist: Potential increase in waist circumference as the pelvic bones widen.

The Role of Body Composition and Genetics

While this adult bone growth is a physiological reality, it's not the only factor that influences hip size and shape. Genetics play a crucial role, determining your fundamental bone structure and the natural areas where your body stores fat. For example, some individuals are genetically predisposed to a "pear" or "hourglass" body shape, with a tendency to accumulate fat around the hips and buttocks, while others have a more "apple" or "straight" shape.

Lifestyle factors, particularly diet and exercise, cannot change your underlying bone structure, but they can significantly impact the amount of muscle and fat surrounding your hip bones. Activities like strength training can build muscle in the gluteal and thigh regions, enhancing the overall appearance of the hips. Conversely, a sedentary lifestyle and poor diet can lead to increased fat accumulation in the same areas, which, when combined with natural pelvic widening, can lead to a more significant increase in waist and hip measurements over time.

Maintaining Hip and Pelvic Health

Understanding that your hip bones continue to change is key to maintaining overall health throughout life. Unlike the inevitable pelvic widening, conditions like osteoporosis—which cause a loss of bone density—can be actively managed. Here are some strategies for maintaining strong and healthy hip bones:

Weight-Bearing Exercise: Regular exercise that forces you to work against gravity is one of the best ways to build and maintain bone density. Activities such as walking, jogging, dancing, and strength training with weights or resistance bands are excellent options.
Adequate Nutrition: A diet rich in calcium and vitamin D is essential for strong bones. Calcium is the primary building block of bone, while vitamin D helps your body absorb it. Foods like dairy products, leafy greens, fortified cereals, and fatty fish are great sources.
Fall Prevention: For older adults, especially those with declining bone density, preventing falls is critical. Measures include removing tripping hazards at home, ensuring good lighting, and using balance-enhancing exercises like Tai Chi.
Avoid Smoking and Excessive Alcohol: Both smoking and heavy alcohol consumption have been shown to negatively impact bone mass and increase fracture risk.

Conclusion

In summary, the answer to the question, do hip bones keep growing, is a definitive yes, though not in the way we typically think of childhood growth. While longitudinal growth for height ceases around age 20, the pelvis continues to undergo a process of remodeling that results in a gradual widening throughout adulthood. This natural phenomenon, combined with changes in body composition, can influence a person's body shape over time. Understanding this distinction is valuable for anyone seeking to differentiate between natural aging and modifiable lifestyle factors when it comes to managing their body shape and overall health. By focusing on good nutrition and weight-bearing exercise, you can support your bone health for years to come, regardless of the body's natural changes.

For more information on bone health, consult authoritative sources such as The Basics of Bone in Health and Disease.

Frequently Asked Questions

While long bone growth responsible for height stops around age 20 when growth plates fuse, certain bones like the pelvis undergo continuous remodeling, causing them to widen over time.

Scientific studies using CT scans have found evidence that the pelvis can continue to widen well into a person's 70s, long after skeletal maturity is reached in their mid-twenties.

No, exercise cannot change your inherent bone structure, which is determined by your genetics. However, exercise can alter the muscle and fat mass around your hips, changing their overall appearance.

While weight gain and fat accumulation contribute to a larger waistline, studies have shown that the pelvic bones themselves also grow wider over time, independent of fat accumulation.

Childhood growth involves endochondral ossification at active growth plates, leading to increased height. Adult widening is a process of lifelong bone remodeling that increases width, not height, and occurs after growth plates have closed.

Bone growth, or ossification, builds new bone mass, especially during childhood. Bone remodeling is a continuous process of old bone breakdown (resorption) and new bone formation that occurs throughout life to maintain bone health and adapt to stress.

Maintaining healthy hip bones involves a balanced diet rich in calcium and vitamin D, regular weight-bearing exercise to strengthen bones, and taking preventative measures to avoid falls, which is especially important as bone density can decline with age.