ETIOLOGY OF THE OBESITY EPIDEMIC
Increasing activity levels may bring diminishing returns
due to compensatory responses in nonactivity energy expenditure [66]. In 1,754 adults with DLW measured seven
years apart, only 72% of the extra calories burned during activity translated into extra
calories expended that day, because the body offset the calories burned in activities by
28%. Among those with BMI ≥34, compensation of burned activity calories increased to 46%
[72].
THE REGULATION OF BODY WEIGHT
Because both sides of the energy balance equation are
affected after weight loss, the biological pressure to gain weight is a consequence of both
increased appetite and suppressed energy expenditure as the body attempts to restore energy
homeostasis [15,108]. Termed metabolic adaptation, this defense
of established adiposity against weight loss recapitulates a physiological response that
signals potential starvation [69,104].
Each naltrexone/bupropion tablet contains naltrexone 8
mg plus bupropion 90 mg. The target maintenance dose of 4 tablets daily (naltrexone 32
mg/bupropion 360 mg) daily is shortened with the prolonged-release formulation (NB32). The
initial dose is 1 tablet daily, increased stepwise to the target of 2 tablets twice daily.
Typical weight loss seen in practice is around 5% to 6% with NB32s [131].
However, a meta-analysis of data from the National
Epidemiologic Survey on Alcohol and Related Conditions and the National Comorbidity
Survey-Replication found a decreased prevalence of obesity among current users of cannabis
(≥3 days per week) of 14.3% and 17.2%, respectively [185]. Given this decreased likelihood of obesity in current cannabis users,
research has begun to explore how the endocannabinoid system can be manipulated to promote
weight loss and improve metabolic health.
Given the significantly greater weight loss with
semaglutide (15%) than other currently approved antiobesity medications (6% to 10%) and with
69% and 50% of subjects attaining weight loss ≥10% and >15%, respectively, semaglutide
2.4 mg weekly is recommended as the first-line antiobesity medication for obesity management
[131]. Weight-loss goals for most
individuals with obesity should be at least 10% or more, which is now achievable with
current antiobesity medications.
BARIATRIC SURGICAL PROCEDURES AND DEVICES
Three intragastric balloon devices are ASMBS-endorsed
and FDA-approved for six-month dwell-time. The Orbera and Reshape balloons are both filled
with methylene blue and saline. A leak or rupture releases the dye, which turns the urine
blue to rapidly reveal the problem [135,228].
Contraindications to intragastric balloon devices use
include prior abdominal or weight-reduction surgery, inflammatory bowel disease,
obstructive disorders, GI ulcers, severe reflux, prior GI bleeding, severe liver disease,
coagulopathy, ongoing alcohol use disorder, or intestinal varices, stricture, or stenosis
[239,245].
Orbera, the most widely and longest used intragastric
balloon device, is an endoscopically inserted single gastric balloon filled with 400–750
mL of fluid [245]. In a meta-analysis of
1,683 patients, weight loss at 6 and 12 months was 13.2% and 11.3%, respectively. Common
adverse events were pain (34%), nausea (29%), GERD (18%), gastric mucosal erosion (12%),
and balloon removal due to intolerability (7.5%). Severe events included gastric ulcers
(2.0%), balloon displacement (1.4%), small bowel obstruction (0.3%), perforation (0.1%),
and death (0.08%). All perforations occurred in patients with prior gastric surgery; all
deaths were secondary to perforation or aspiration. Thus, individualized, detailed risk
assessment is necessary for patients planning to undergo intragastric balloon device
placement [228]. Orbera early removal is
also associated with use of selective serotonin or serotonin-norepinephrine reuptake
inhibitors (SSRIs/SNRIs) [125].
