Updated on October 23rd, 2023 at 07:36 pm

When you wear a tight outfit, you want it to look beautiful on you. So, it’s a little frustrating when you notice uneven bulges from under the bra. You know it shouldn’t ruin your confidence, but you can’t help but wonder, what causes back fat under your bra?

You accumulate back fat mainly due to not following a proper diet or engaging in enough strength or resistance training to tone the upper body. Incorrect bra sizing can also result in breast tissue being pushed upwards or downward, causing fat tissue to be pushed into one concentrated area.

Let’s look at what you can do about back fat.

Feel comfortable in your bra

While removing bra bulge may be a realistic goal if you want to look great in a specific outfit, it’s also highly beneficial for your health. In addition to the abs, your back forms your core; hence it’s crucial to your daily movements. Toning your back will ensure you maintain a long life full of health and vitality.

image of what causes back fat under your bra - Extra Large Living

Practicing strength exercises and resistance training activities will help you improve posture and reduce body weight. Back fat is often caused by a lack of exercise and a poor diet which leads to the accumulation of back fat under their bra.

Did you know?

Lack of resistance training is not the only reason you accumulate back fat under your bra. Another contributing factor to back fat is wearing an incorrect bra size and style. 

While maintaining a healthy weight and engaging in weight loss activities is key to shredding fat in this area, underarm fat and back fat are compressed because of wearing an ill-fitting bra.

Before considering breast reduction, consider purchasing the correctly sized bra to alleviate this issue. A healthy diet will help reduce the amount of fat accumulating in your body. 

Note: An ill-fitting bra can cause more damage than you may know.

Wearing a bra that does not properly hold your breasts is one of the main reasons some people get excess underarm bulging. It is a well-known fact that most women are wearing incorrectly-sized bras. Attending a bra fitting is the best means of determining the correct bra size for your current body weight.

They will be able to ascertain your bra band and band size quickly and efficiently, inherently reducing the accumulation of back fat under your bra. It is also important to note that a bra does not pull your boobs into the center of your chest. Instead, it tightly fits around your breast band, causing tissue to migrate to a specific body area.

What can I do about breast tissue migration?

Losing weight, engaging in strength training, and toning your entire body are ways to ensure that excessive breast tissue does not migrate when wearing a bra.

Wearing wide straps may also help you to contain any excessive back fat accumulating under your bra. Toning core muscles is also undoubtedly helpful, and enhancing the strength of your upper back muscles will also greatly assist this process.

What is polymastia?

Some women unknowingly suffer from a condition called polymastia. This condition causes excessive breast tissue to develop in the armpit area and across the area that surrounds the breast.

Having larger breasts can also contribute to excess breast tissue and fat accumulation under your bra. This occurs because breast tissue may push upwards or downwards, causing more stored fat to crease and become noticeable under your bra.

For instance, a woman with larger breasts may have excessive tissue pushing against the fat in her arms, resulting in a bulkier appearance.

How to get rid of back fat or under-bra bulge?

image of what causes back fat under your bra - Extra Large Living

The first step to removing back fat is to ensure that you wear the right bra. The next step is to ensure that you engage in strength exercises targeting the upper-back area.

Women with broader shoulders may neglect the upper back area as they believe they may become too bulky or manly. However, these exercises are key to removing excessive back fat that accumulates under your bra.

Why do I need to get rid of the bra bulge?

Excessive fat under your bra will make your clothes fit strangely. This causes your bra to dig into your skin, altering your appearance. A healthy combination of regular resistance training and a balanced diet will ensure that you easily burn fat that accumulates under your bra.

How does fat develop?

Whenever your body has excessive calories, these calories will be converted into fat. While everyone will have specific areas where fat accumulates the most (under the bra, for instance), fat rarely just accumulates in one area alone.

As such, fat accumulating on your back indicates that fat has accumulated throughout your entire body.


To conclude, back fat will accumulate under your bra for numerous reasons. The main reason is that you are not following a healthy diet or engaging in enough strength or resistance training to lose body weight.

Back fat only tends to accumulate due to excessive fat throughout the entire body. Therefore, if you concentrate on strengthening exercises, you will likely lose excess fat that accumulates under your bra. However, there are other reasons why back fat may accumulate under your bra area.

Wearing the wrong bra size will result in breast tissue being pushed upwards or downwards, which causes fat tissue to be pushed into one concentrated area. If you suffer from excessive breast tissue that accumulates in your armpits, this may also enhance the amount of fat stored under your bra.

Some women accumulate fat under their bras due to a condition called polymastia. This condition occurs whenever excessive breast tissue grows in the armpit area, which inherently impacts the amount of fat that accumulates around the bra.

Wearing wider straps can help to hide excessive breast tissue in this instance. I hope that you have found this article to be informative. Thank you for reading.