N.O.K. Nederlandse Obesitas Kliniek BV

The goal of this clinical trial is to investigate the effects of daily protein supplementation and participation in a weekly supervised resistance training program on the prevention of excessive muscle mass loss following bariatric surgery. Patients treated at one of the participating centers will be invited to participate and will be randomly assigned to one of two groups.
Participants in group 1 will receive standard postoperative care as currently provided. Participants in group 2 will also receive standard care, but in addition, they will be asked to consume extra protein daily and take part in a supervised resistance training session once a week.
Previous research has shown that approximately one in five patients undergoing bariatric surgery experiences excessive muscle loss after the surgery. It is known that resistance training and protein intake can help maintain and even improve muscle mass. However, limited research has been conducted on the combined effects of protein supplementation and resistance training in patients after bariatric surgery. Therefore, the aim of this trial is to determine whether participants receiving the additional intervention experience less muscle mass loss compared to those receiving standard care alone.

Although bariatric surgery is currently the most effective treatment for morbid obesity, weight regain occurs in 16-37% of the patients (1). Weight regain is not regularly treated with antiobesity medications (AOMs).
Mysimba (Contrave in US) is a AOM, it is a combination of naltrexone hydrochloride extended release and bupropion hydrochloride extended release for the treatment of obesity, and is used with lifestyle modification. Bupropion is a mild reuptake inhibitor of dopamine and norepinephrine. Naltrexone, an opioid antagonist has minimum effect on weight loss on its own. Naltrexone is thought to block the inhibitory effects of opioid receptors activated by the β-endorphin released in the hypothalamus that stimulates feeding, thus allowing the inhibitory effects of α-melanocyte stimulating hormone to reduce food intake. In patients with obesity usage of Naltrexone/Bupropion (NB) results in up to 8.2% weight loss (2). There is some evidence that also in bariatric patients with weight regain NB leads to additional weight loss (3, 4).
At the Nederlandse Obesitas Kliniek (NOK) weight regain at follow-up is currently treated with the Back on Track (BOT) program. The BOT program is an extra intervention our clinic provides for the patients who have weight regain after surgery, this is part of our standard care program.
The primary objective is to study the effect of naltrexone/bupropion in combination with the BOT module on successful weight loss(>5% weight loss) after 22 weeks in patients with weight regain after bariatric surgery, compared to the regular BOT module.