When you begin a weight loss journey, a common question is whether the size of your “bum”—defined by the gluteal muscles and the overlying fat tissue—will decrease. The straightforward answer is typically yes; the gluteal region will become smaller as you lose overall body mass. The overall size reduction is a direct result of decreasing the volume of the subcutaneous fat stored in this area. However, the exact degree of change and the resulting shape are highly dependent on individual biological factors, specifically how your body is programmed to store and release fat.
How Fat Storage Works in the Gluteal Region
Body fat loss happens systemically across the entire body, meaning the idea of “spot reduction” is not supported by science. When you create a caloric deficit, your body signals for the release of stored energy (triglycerides) from fat cells all over your body. These are converted into free fatty acids that are then transported through the bloodstream to be used as fuel. No amount of targeted exercise, such as glute bridges, can force the fat surrounding the working muscle to be released first.
The reason many people find the gluteal region stubborn for fat loss relates to genetics and sex hormones. Estrogen plays a significant role in promoting a gynoid fat distribution pattern, which favors fat storage in the hips, thighs, and buttocks. This lower-body fat, known as gluteofemoral fat, is often more resistant to lipolysis (the process of fat breakdown). Because of these hormonal and genetic predispositions, the gluteal region may be one of the last areas to show significant size reduction.
Understanding Gluteal Composition: Fat Versus Muscle
The size and shape of the gluteal region are determined by subcutaneous fat tissue and three primary muscles: the gluteus maximus, gluteus medius, and gluteus minimus. The fat tissue shrinks in response to a caloric deficit, reducing the overall volume and circumference of the area. Weight loss that focuses solely on diet, however, can result in the loss of both fat and muscle mass, sometimes leading to a less toned or “flat” appearance.
Muscle tissue is denser than fat tissue, meaning a pound of muscle takes up less physical space than a pound of fat. While fat loss decreases volume, maintaining or increasing the size of the gluteal muscles provides the desired shape, lift, and firmness. The gluteus maximus, the largest muscle in the human body, is particularly influential in determining the final contour after weight loss. Preserving this muscle mass is important because strong gluteal muscles are also linked to better metabolic health.
Maintaining Shape During Weight Loss
To support the gluteal region’s shape during fat loss, a combined approach of resistance training and adequate nutrition is highly effective. Resistance training signals to the body that muscle tissue must be preserved or strengthened. Compound movements are particularly effective, as they engage the glutes along with other large muscle groups; examples include squats, lunges, deadlifts, and hip thrusts.
Pairing this training with a higher protein intake is necessary to ensure the muscle has the building blocks it needs to repair and grow, even in a calorie deficit. Consuming approximately 0.7 to 1.0 grams of protein per pound of body weight daily is recommended for preserving lean mass. Stimulating the muscle tissue encourages the body to prioritize fat for energy while maintaining the structural foundation of the gluteal region.