Help! My Butt Is Disappearing

Q. I’ve managed to lose 16 pounds from working out—but my already-flat butt is rapidly disappearing! It wasn’t big to start with so I want to keep what I’ve got. How can I continue to exercise without losing my rear end?

A. One of the most frustrating aspects of losing weight is that the fat you lose doesn’t always come from the body parts where you want to lose it. Some people find that they lose weight from everywhere but their stomach, or some lose in their breasts, but not their thighs.

Body-fat distribution is highly genetic—which explains why people tend to have a similar body type as their parents and siblings. Body-fat loss is also genetic, and no matter how many hyped-up claims you hear from infomercials or those trying to push miracle body-transformation products or techniques, there is no way to tell the body how and where to lose its fat.

Typically, people who lose weight tend to create a smaller version of their same body shape. If you already had a small derriere, chances are you have small amounts of muscle and small amounts of fat tissue in the area. Losing weight may have caused you to lose some of the fat; if you lost the weight too quickly, you may have also lost some muscle tissue.

You may be able to build your butt back up by increasing the muscle mass in your glutes, a process known as hypertrophy. But it may be impossible to build muscle if you are losing weight. The recipe for building muscle is to do resistance training one to three times per week, and to eat extra calories to fuel the anabolic process of creating new muscle tissue. (To target the gluteal muscle in your rear end, you should include weighted squats, lunges and step-ups on a bench.) If you plan to continue losing weight, you may be able to preserve the butt muscle you still have by lifting weights during your periods of weight loss.

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Martica is a Manhattan-based exercise physiologist and nutritionist and an award-winning fitness instructor. She has written for a variety of publications including Self , Health , Prevention , The New York Times and others. Martica is the author of seven books, including her latest, - Cross-Training for Dummies . (Read her full bio.)