Understanding Your Body: Why Did My Hips Become So Wide?

October 2, 2025 •

3 min read

Research has revealed that the human pelvis can continue to grow and change well into adulthood, an often surprising discovery that helps explain some body transformations. Several factors contribute to this phenomenon, so if you've been asking 'Why did my hips become so wide?', the answer is a complex combination of natural biological processes.

Quick Summary

Hip widening is a common occurrence resulting from a complex interplay of hormonal shifts during puberty and pregnancy, genetic predisposition determining skeletal structure, and the body's natural changes in fat distribution. Age-related pelvic bone remodeling also plays a subtle role, contributing to a gradual increase in hip circumference over time for many individuals.

Key Points

Puberty's role: Hormonal changes, particularly estrogen, cause pelvic widening and fat redistribution during adolescence.
Genetic blueprint: Your family history determines your underlying bone structure and how your body naturally distributes fat.
Age and bone changes: Studies show pelvic bones can continue to widen gradually well into mid-adulthood.
Pregnancy's effect: The hormone relaxin temporarily loosens pelvic ligaments, potentially causing a slight, permanent increase in hip width.
Body composition changes: Overall weight gain, especially in women, often leads to fat accumulation in the hips and thighs. Building gluteal muscle can also contribute to a wider appearance.
Health over fixation: Rather than focusing on one body aspect, prioritize holistic health through diet and exercise for a balanced physique.

Hormones and Your Body's Design

Your body's shape is heavily influenced by hormonal shifts throughout your life. For females, the hormone estrogen is a primary architect of body contours, particularly during puberty.

Puberty's Shaping Influence

During adolescence, a surge of estrogen triggers the development of secondary sexual characteristics. This includes breast development, the onset of menstruation, and the widening of the pelvic bones. This widening has an evolutionary purpose: to prepare the body for potential childbirth by creating a wider birth canal. This change is part of a natural, genetically-programmed process and is a normal part of transitioning into an adult body shape. For many, this is the most significant period of hip-related growth.

The Impact of Pregnancy

For those who have been pregnant, the experience can also cause hips to widen. During pregnancy, the body releases a hormone called relaxin, which softens and loosens the ligaments and joints in the pelvis. This is a crucial step to allow the pelvis to expand for childbirth. While some of this widening can be temporary, some women may experience a slight, permanent increase in hip width postpartum. This is true even for those who undergo a C-section, as the hormonal changes occur regardless of delivery method.

The Role of Genetics and Bone Structure

While hormones direct many changes, your fundamental body frame is determined by genetics. Your bone structure, including the width of your pelvis, is largely inherited from your parents. If wider hips are common in your family, you are more likely to have them as well. This genetic blueprint dictates the maximum width of your skeletal structure, which forms the foundation of your hip area. Different people within the same family can still have variations in hip structure due to complex genetic inheritance.

Understanding Weight Fluctuation and Fat Distribution

Changes in fat and muscle mass also directly impact hip size. The distribution of body fat is influenced by a combination of genetics and hormones. Women are naturally predisposed to store more fat in the hips, thighs, and buttocks—a body type often referred to as 'pear-shaped'. This fat accumulation can cause a noticeable increase in hip width with overall weight gain. Conversely, overall weight loss will help reduce this fat, but it's important to remember that fat reduction cannot be spot-targeted; it happens across the entire body.

Muscle Development and Hip Appearance

Specific exercises that target the gluteal muscles (gluteus maximus, medius, and minimus) and outer thighs can build muscle mass in the hip area. This can contribute to a fuller, rounder appearance. For example, exercises like squats, lunges, and hip abductions can strengthen these muscles, leading to more defined and potentially wider-looking hips.

Adult Pelvic Remodeling

Contrary to previous beliefs, research has shown that pelvic bone growth doesn't necessarily stop in the early 20s. A 2011 study published in the Journal of Orthopaedic Research found that the female pelvis can continue to widen well into adulthood, up to around age 40, before a slight narrowing in later life. This bone remodeling is thought to be influenced by hormonal changes and mechanical stress over time.

Comparison of Widening Factors


Factor	Timing of Impact	Primary Mechanism	Degree of Change	Reversibility
Puberty	Adolescence	Estrogen increases pelvic bone width and fat redistribution.	Significant, foundational change.	Not reversible (permanent skeletal change).
Pregnancy	During gestation	Relaxin hormone loosens pelvic ligaments.	Temporary, though slight permanent change is possible.	Mostly reversible postpartum.
Weight Gain	Any time	Increased fat deposits around hips and thighs.	Variable, depends on weight gain.	Largely reversible with weight loss.
Aging	Mid-adulthood	Gradual pelvic bone remodeling and hormonal shifts.	Subtle, gradual change over decades.	Not reversible (part of natural aging).

Conclusion: The Holistic View of Your Body

Instead of searching for a single culprit, it is more accurate to view hip widening as the result of a holistic and natural progression. It is a mosaic of factors including your genetic blueprint, the hormonal shifts of puberty, the reproductive demands of pregnancy, the body’s natural fat storage patterns, and even subtle changes with age. Embracing these natural transformations can foster a healthier and more positive body image. Focusing on overall health through balanced nutrition and a consistent exercise regimen can help manage body composition in a sustainable way, rather than focusing on a single, predetermined aspect of your shape.

For more detailed information on body composition and health, consider consulting resources from the National Institutes of Health.

Frequently Asked Questions

Exercise cannot change your underlying bone structure, which is the primary determinant of hip width. However, targeted exercises can build and tone the gluteal and thigh muscles, which can give the hips a fuller, more sculpted appearance.

Yes, reducing overall body fat through a healthy diet can decrease the fat stored around your hips. It's important to remember that you can't spot-reduce fat, so a caloric deficit will lead to fat loss across your entire body.

Yes, it is common for hips to widen during pregnancy due to the hormone relaxin loosening pelvic ligaments. While they will largely return to their pre-pregnancy size, a small, permanent increase in hip width is possible for some women.

No, wider hips are not always caused by weight gain. They can be a result of genetic bone structure, hormonal changes during puberty, pregnancy, or the natural bone remodeling that occurs with aging. Weight gain is just one of many potential contributing factors.

Hip dips, or violin hips, are different from overall hip width. They are the inward curves on the sides of the hips caused by the shape of the pelvis and where muscles and fat are distributed. They are a normal anatomical feature determined by genetics.

While the most significant widening happens during puberty, studies show that subtle pelvic bone remodeling can continue in women up until around age 40. The extent of this change varies greatly from person to person.

The pattern of fat distribution is primarily influenced by genetics and hormones. Women tend to store fat in the hips and thighs (pear-shape) due to estrogen, while men and postmenopausal women often store fat in the abdomen (apple-shape).