Do I Have Enough Fat for a BBL? The Skinny BBL Explained

Do I have enough fat for a BBL?

Only an exam can answer that, because no published number decides it. We looked through the American Society of Plastic Surgeons (ASPS), The Aesthetic Society, Cleveland Clinic and the surgical journals for a minimum amount of fat or a minimum BMI, and no source we read sets one. What they describe instead is a judgment: how much fat you can spare, how much room there is under your skin, and what shape you want.

Being lean doesn't rule you out. A smaller transfer, often called a skinny BBL, may suit you, and some lean patients may suit implants instead.

How much fat do you need for a BBL?

There is no required amount, but there is a typical one. Cleveland Clinic says "A large amount of fat is usually needed," "usually 300 ccs to 500 ccs" on each side. That describes what is commonly transferred, not a test you have to pass.

More fat has to come out than goes in. The ASPS procedure page says "your surgeon may liposuction up to three times the amount of fat than what will actually be injected." One reason is that not all of it stays: ASPS says patients retain 60% to 80% of the transferred fat on average, in some cases more and in others less, and a plastic surgeon interviewed by ASPS says 20% to 40% of the injected fat is absorbed by the body during healing.

Where the fat comes from matters as much as how lean you look. Cleveland Clinic lists the lower back, hips, inner thighs and outer thighs among the areas a surgeon examines. That is why a number on a scale can't settle this, and why two people at the same weight can get different answers.

What is a skinny BBL?

A skinny BBL is a BBL for a leaner body, aimed at shape rather than size. In an ASPS article, Dr. Michael Keyes says "A skinny BBL is a BBL performed on leaner patients with lower body fat percentages" and that he typically harvests a smaller volume of fat.

ASPS's article on the trend says the procedure "isn't focused on volume – rather, it focuses on shape and proportion." It describes patients who are often already fit, including "trainers, athletic models and gym-goers," and people who have lost weight on GLP-1 medication. Dr. Johnny Franco, interviewed in that article, says "These patients typically don't have as much fat or adipose tissue to harvest as other BBL patients."

A skinny BBL is still surgery. Fat is removed with liposuction and then injected. We found no study that compares complication rates between skinny and traditional BBLs, so don't assume smaller means safer. The BBL page explains the most serious risk of a BBL and why fat stays under the skin.

Is there a minimum BMI for a BBL?

No published cutoff exists in anything we read. The closest figure is one surgeon's memory: Dr. Franco told ASPS that "When I was first doing BBLs, if patients had a BMI under 22 or 23, they were not a candidate," and that the focus has since moved to shape. That describes his earlier practice, not a rule.

The 2022 Practice Advisory on Gluteal Fat Grafting in Aesthetic Surgery Journal sets no BMI cutoff either. It asks surgeons to weigh "the patient's BMI, the estimated volume of fat to be grafted, and any other concomitant procedures to be performed."

BMI matters for a second reason: room. Fat belongs in the layer under the skin, and that layer is thinner in leaner bodies. An ultrasound study of 150 Caucasian adults found that each 1.0 kg/m² increase in BMI corresponded to about 3 mm more total gluteal fat under the skin in men and 4 mm in women. The authors call this layer "the safe space." The study covered one group of people, so treat it as a pattern and not a measurement of you.

This is where the safety question comes in. A 2018 multi-society advisory says "If the aesthetic goal requires more fat than can be placed in the subcutaneous layer the surgeon should consider staging the procedure rather than injecting deep." In plain words: if your goal needs more fat than the safe layer holds, the answer is a smaller goal or more than one surgery, never deeper injection. Our BMI guide shows what we recommend for a BBL and why.

What are my options if I don't have enough fat?

There are several, and an exam tells you which are realistic for you:

• A smaller transfer. This is the skinny BBL. Expect a subtle change, and ask your surgeon to be specific about how subtle.
• Butt implants. Cleveland Clinic says "If you don't have enough excess body fat available, you may be a good candidate for butt implants," and The Aesthetic Society says that if you "are very slender with little excess fat, your surgeon may recommend butt implants." Cleveland Clinic's implant page says a BBL "may also have a lower risk of complications," so this is a real trade-off. Our comparison of BBL and other body procedures goes further.
• More than one surgery. The advisory above raises staging when the goal needs more fat than one session can place safely. Ask whether your surgeon would consider it.
• Gaining weight first. We found no source telling lean patients to do this. ASPS quotes a surgeon who says a patient "should be relatively close to their ideal body weight," and warns that "As you gain or lose weight, your results may change." Talk to your surgeon before you change your weight on purpose.
• Not fillers. The FDA recommends against using "dermal fillers or any injectable filler" to increase the size of the buttocks.

What should I ask at my BBL exam?

Bring photos of shapes you like, and ask these directly:

• Where would you take fat from, and how much do you estimate you can harvest?
• How much room do I have in the layer under the skin?
• What change can I realistically expect at that amount of fat?
• What happens if less of the fat stays than we hoped?
• Would you recommend a staged plan, implants or no surgery for me, and why?

At your consultation, your surgeon examines you and tells you whether you have enough fat for the result you have in mind. The BBL page covers who is a candidate for a BBL, how the skinny BBL compares with the other types and how the price is set.

Frequently asked questions

Sources

• Cleveland Clinic: Brazilian Butt Lift
• Cleveland Clinic: Butt Implants
• American Society of Plastic Surgeons: Buttock enhancement procedure steps
• American Society of Plastic Surgeons: Less is more, the emergence of the skinny BBL
• American Society of Plastic Surgeons: Is "BBL smell" real?
• American Society of Plastic Surgeons: Seven things you need to know about a Brazilian butt lift
• American Society of Plastic Surgeons: Six things you need to know about recovering from a Brazilian butt lift
• Multisociety Gluteal Fat Grafting Task Force: Safety Advisory, January 31, 2018
• The Aesthetic Society: Butt Lift and Augmentation Procedure Overviews
• Aesthetic Surgery Journal: Practice Advisory on Gluteal Fat Grafting (Del Vecchio and Kenkel, 2022)
• Plastic and Reconstructive Surgery: gluteal subcutaneous fat thickness by ultrasound (Frank and colleagues, 2019)
• FDA: Dermal Fillers (Soft Tissue Fillers)