What Patients with a BMI Below 17.5 Should Know Before Fat Transfer Breast Augmentation

“I want a larger bust, but I don’t want silicone implants.”

This is a common request among patients considering fat transfer breast augmentation.

Fat grafting offers several advantages:

• Natural appearance
• Natural feel
• No permanent implant

However, one important reality is often overlooked:

Fat retention varies significantly from patient to patient.

Not everyone will achieve the same level of long-term volume retention.

Two Major Factors That Can Reduce Fat Retention

Based on our experience performing numerous fat transfer breast augmentations, two factors are particularly important:

✔ BMI below 17.5

✔ Smoking or frequent exposure to secondhand smoke

Patients who fall into either category often face greater challenges with fat survival.

Why Do Slim Patients Have Lower Fat Retention?

Fat cells require:

• Adequate blood supply
• Adequate nutrition

to survive after transfer.

Patients with very low BMI often have:

• Less donor fat available
• Less tissue volume within the breast

As a result, blood flow may not adequately support large amounts of transferred fat.

This can increase the percentage of fat that is absorbed over time.

How Smoking and Secondhand Smoke Affect Fat Survival

Successful fat grafting depends on healthy microcirculation.

Nicotine and tobacco exposure can constrict blood vessels and reduce blood flow.

When blood flow decreases, oxygen and nutrients may not adequately reach newly transferred fat cells.

This can negatively impact fat retention.

For this reason, AVAN TOKYO strongly recommends avoiding smoking before and after surgery whenever possible.

Case Presentation

The patient featured in this case was:

• 19 years old
• BMI 17

She underwent:

• Circumferential arm liposuction
• Fat transfer breast augmentation

Because of her work environment, she was also frequently exposed to secondhand smoke.

At 6 months postoperatively, a significant portion of the transferred fat had been absorbed.

This case highlights that long-term results depend not only on injection volume but also on biological and lifestyle factors.

Better Options for Slim Patients

For patients with a low BMI, AVAN TOKYO often recommends:

Option 1: Multiple Fat Transfer Sessions

Rather than attempting a dramatic increase in a single procedure, gradual augmentation through two or three sessions may improve outcomes.

The second procedure may benefit from:

• Increased vascularity
• Expanded tissue capacity

which can improve fat retention.

Option 2: Hybrid Breast Augmentation

Hybrid Breast Augmentation combines:

• Silicone implants for reliable volume
• Fat grafting for softness and natural contour

For slim patients, this approach often provides the most predictable and satisfying result.

The AVAN TOKYO Philosophy

Fat transfer breast augmentation is not about injecting the largest possible volume.

The true goal is:

• Maximizing fat survival
• Creating a natural breast shape
• Achieving long-term satisfaction

Every treatment plan should be tailored to the patient’s anatomy, BMI, lifestyle, and goals.

Case Information

Patient: 19-Year-Old Female

BMI: 17

Procedure: Circumferential Arm Liposuction + Fat Transfer Breast Augmentation

Follow-Up: 6 Months

Risks and Complications

Fat Transfer Breast Augmentation:
Infection, palpable lumps, fat necrosis, calcification, asymmetry, variable fat retention, volume loss, and scarring.

Liposuction:
Swelling, bruising, fibrosis, contour irregularities, pigmentation changes, sensory changes, and scarring.