The role of BMI in selecting patients for cryolipolysis
Body mass index (BMI), defined as weight (in kg) divided by height (in metres) squared, remains a reference indicator in medicine for estimating excess weight. It classifies patients according to the following thresholds :
- BMI < 18,5 : underweight.
- BMI 18,5 – 24,9 : normal weight.
- BMI 25 – 29,9 : overweight.
- BMI ≥ 30 : obesity (divided into 3 grades).
For cryolipolysis treatment, BMI provides guidance but cannot alone determine whether the procedure is feasible. It is an overall indicator that does not reflect fat distribution, skin tone or the type of fat (subcutaneous or visceral), all crucial criteria for treatment success.
Ideal BMI for effective cryolipolysis
According to medical literature, cryolipolysis produces the best results in patients with a body mass index (BMI) between 20 and 27. These patients have a generally balanced figure but small localised fat deposits, often on the abdomen, flanks, saddlebags or inner thighs. These well-defined areas, readily accessible to applicator suction, contain subcutaneous fat that cryolipolysis can treat effectively.
Under these conditions, the technique offers visible, harmonious and lasting results. It does not change overall weight but provides a targeted, measurable reduction in the volume of treated areas for a more refined figure.
Can cryolipolysis be offered to an overweight patient ?
Cryolipolysis can certainly be considered in a patient with a BMI between 27 and 30, meaning moderate excess weight, provided the excess fat remains localised, accessible and stable over time. The aim is to target one or two precise areas for partial contouring rather than treat excess weight as a whole.
However, several points require particular attention in this situation :
- Assessment must exclude visceral obesity (deep internal fat), on which cryolipolysis is ineffective.
- Skin laxity must not be marked, as this could produce an insufficient or aesthetically unsatisfactory result.
- The patient must be informed that cryolipolysis will not lower BMI but will improve a specific area of their figure.
Is cryolipolysis contraindicated in patients with obesity ?
In patients with a BMI above 30, cryolipolysis is not indicated as a first-line treatment. Fat deposits are often diffuse and deep, and also associated with a significant visceral component entirely inaccessible to this technique.
Offering cryolipolysis in this context would be ineffective or even misleading. Obesity requires comprehensive medical or surgical management including a nutritional strategy, supervised physical activity and sometimes bariatric or reconstructive surgery.
However, cryolipolysis may be considered during weight stabilisation in a patient who has lost weight, to correct residual localised excess fat, provided the skin has regained some tone. In this case, it is a complementary finishing treatment.
Low BMI and cryolipolysis
The question of cryolipolysis effectiveness in slim patients or those with a low BMI (below 20) also arises. At first glance, these patients might seem ideal because they do not have excess weight. However, several precautions are necessary.
First, if the fat fold is too thin, performing the session is technically difficult : suction is insufficient, cold exposure is uneven and treatment effectiveness may be compromised. Second, very slim patients have a higher risk of surface irregularities or asymmetry because the fatty tissue is shallow and the skin sometimes thin and lacking elasticity.
Finally, some low-BMI patients may have mild body dysmorphic concerns or unrealistic expectations, which should be identified tactfully. The doctor's role is central in setting ethical limits and avoiding an inappropriate procedure.
BMI alone is insufficient to establish an indication for cryolipolysis
Although BMI is a useful starting point, it can never be sufficient to establish an indication for cryolipolysis. A complete clinical assessment remains essential. It should include :
- Skinfold measurement : the thickness of the fat bulge when pinched. It must exceed 2,5 cm for cryolipolysis to be indicated.
- Analysis of skin quality (elasticity, absence of major laxity).
- Precise localisation of fat to distinguish subcutaneous fat, accessible to cryolipolysis, from deeper fat.
- Assessment of lifestyle, recent weight and patient motivation.
This personalised approach, based on an overall view of the patient, determines treatment effectiveness and result quality well beyond simply interpreting a BMI.
Why is a stable BMI essential before cryolipolysis ?
The patient's weight at the time of treatment directly influences result quality and durability. Cryolipolysis performed during weight fluctuations (recent weight loss or gain, an ongoing diet or active metabolic disorders) may produce effects that are difficult to assess or even temporary. It is therefore recommended that BMI should have been stable for at least three months before considering a cryolipolysis session.
This stability ensures that the targeted fat fold represents genuine, persistent excess fat rather than a temporary weight fluctuation. In a patient still losing weight, the area may naturally reduce, making the session unnecessary. Conversely, weight regain after treatment can erase the benefits obtained.
Within a rigorous medical approach, cryolipolysis is offered only once weight has stabilised, to ensure a harmonious, lasting result.
What is the doctor's role in assessing the ideal profile for cryolipolysis ?
Body mass index cannot be considered as an isolated number. The doctor's role is to interpret its value within an overall clinical context. This assessment must consider fat distribution, skin quality, medical history, patient motivation and how the patient perceives their body.
Two patients with the same BMI may actually have very different profiles. One may have diffuse fat distribution that is poorly accessible to treatment, while the other has well-localised deposits suitable for cryolipolysis. In the first case, results would be limited ; in the second, the technique would be entirely relevant.
Assessment must also consider whether expectations are appropriate. A normal-weight patient seeking perfection or with an altered perception of their body image is not always a suitable candidate. The indication for cryolipolysis must be established with discernment after a careful consultation based on both clinical examination and genuine discussion with the patient.
