Diet and exercise are the 2 most basic medical therapies for fat excess. Once medical disorders contributing to weight gain, such as hypothyroidism, have been ruled out by an internist, referral to a nutritionist is recommended. Exercise through a trainer or exercise class is also recommended.

Only a few oral medications are approved by the US Food and Drug Administration (FDA) for the treatment of obesity and intended for use in patients with BMI >30 kg/m² or >27 kg/m² with a comorbidity risk factor (eg, diabetes, hypertension).²¹ These drugs include orlistat, lorcaserin, combination phentermine and topiramate, and combination bupropion and naltrexone. A newer drug class of glucagon-like peptide (GLP)-1 agonists, previously used for diabetes, is emerging as effective weight loss medications. They should be used in concert with diet, exercise, and behavior modification. After 12 weeks of use, 5% or more weight loss should be expected or the medication discontinued. An FDA warning has been issued regarding over-the-counter weight loss and “dietary” supplements. In 2015, the FDA banned amphetamine-like stimulant BMPEA, also known as acacia rigidula.

A fat substitute olestra, a sucrose polyester with 6 to 8 fatty acid side chains, is approved as a dietary supplement. Olestra is too large to be hydrolyzed and is excreted without being absorbed. Supplementation with fat-soluble vitamins is recommended.

The currently available noninvasive techniques used to accomplish fat reduction can be divided into 4 main categories: low-level laser therapy (LLLT), cryolipolysis, radiofrequency (RF), and ultrasound. The latter category can be further subdivided into low-intensity/low-frequency ultrasound and high-intensity focused ultrasound (HIFU).

Low-Level Laser Therapy. LLLT has been used for decades as a noninvasive, nonthermal technique to reduce pain and inflammation as well as to stimulate healing and wound regeneration.²²,²³ Over the past decade, LLLT has been examined as an adjuvant to other fat reduction methods as well as monotherapy for noninvasive body contouring. The process by which LLLT accomplishes adipocyte injury has yet to be fully elucidated. The prevailing theory has centered on the ability of the 635-nm-wavelength lasers to penetrate to the level of the subcutaneous fat and cause pore formation in the adipocyte cell membrane with subsequent release of lipids into the interstitial space.²⁴ The extravasated lipid is then removed via the lymphatics with an overall reduction in volume. Subsequent studies looking at pore formation could not replicate these findings, and the mechanism of action of adipocyte reduction by LLLT thus remains somewhat controversial.²⁵ The Zerona LipoLaser (Erchonia Medical, Inc, Melbourne, FL USA) was the first device to be granted FDA approval in the United States for noninvasive circumferential reduction of the waist, hips, and thighs. This device features 5 rotating diode laser heads that each emit 17 mW of 635 nm laser light.²⁶

Protocols. Well-designed studies and clinical trials have demonstrated an average reduction of 3.51 to 5.17 in circumferential measurements across the waist, hips, and thighs after only 2 weeks.²⁷,²⁸ Current standard calls for 6 to 12 treatments, up to 40 minutes, delivered 48 hours apart over 2 weeks. The number of treatment sessions is often dictated by the patient’s body habitus and fat reduction needs.

Adverse Events. LLLT is extremely well tolerated with almost no reportable adverse effects, although thermal injury can theoretically occur. Patient dissatisfaction is higher with this modality compared with other devices that will be discussed, likely because of unrealistic patient expectations when LLLT is used as monotherapy.

Mesotherapy/Deoxycholate. Injection of substances into the mesodermally derived subcutaneous tissues, termed mesotherapy, was first described in the 1950s when Dr Pistor attempted to treat asthma using injectable procaine.²⁹ Today, mesotherapy is primarily employed for cosmetic purposes, namely, local fat reduction.

Cosmetic fat reduction via subcutaneous injection is accomplished through 1 of 2 mechanisms: lipolytic stimulation or ablative mesotherapy. Lipolytic stimulation relies on the premise that an individual’s fat distribution is related to the lipolytic threshold of fat cells, which varies based on gender and anatomic location. By injecting substances that reduce the lipolytic threshold, a temporary decrease in focal adiposity may be accomplished.³⁰,³¹ Ablative mesotherapy is the more commonly employed modality by which detergents are used to achieve permanent destruction of adipocytes. In 2015, a
synthetic form of deoxycholic acid, ATX-101 (Kybella), was approved by the FDA as the first pharmaceutical intervention for submental fat reduction.