Losing weight can seem like an impossible challenge. But why is it so difficult? And what solutions exist to combat obesity? Top endocrinologist Professor Barbara McGowan explains the mechanics behind losing weight and the options that are available to help you lose weight.
Why is it difficult to maintain weight loss?
Our bodies are designed in such a way as to preserve energy to protect us in times of famine. When we lose weight through a diet, for example, our gut hormones change in such a way as to increase our hunger hormones – namely ghrelin—and to decrease our satiety hormones, on balance making us feel more hungry.
What’s really interesting is that even one year after we finish our diet, our gut hormones still remember that we’ve lost calories and the hunger hormones remain high and the satiety hormones remain low – they haven't gone back to baseline. Not only that, our basal metabolic rate after weight loss is lower; that is, the energy required for all our metabolic processes is less than it used to be. This means that on balance, when we lose weight because of the changes in the gut hormones and the fact that we require less calories to maintain our basal metabolic processes means that it’s that much harder to keep that weight loss off over time.
What options are available for weight loss?
There are many options available for weight loss, but the cornerstone of all these options, of course, is lifestyle interventions – dietary changes and increased exercise. For some patients, lifestyle alone is not enough and then we have to look to other options, including pharmacotherapy and bariatric surgery.
Pharmacotherapy can be very useful in achieving weight loss and we do have a variety of agents that we can choose from. Some of these mimic some of our natural hormones, in particular our satiety hormones, which speak to our brain to let it know that we are full. These interventions can be effective in achieving and maintaining weight loss.
Moving on from pharmacotherapy, there are some endoscopic options such as the gastric balloon and the EndoBarrier, which are endoscopically placed into our gut. Again, these have been found to be useful in achieving and maintaining weight loss, although these procedures are temporary and once the device is removed, then the satiety signal is also removed and not sustained.
Finally, we have bariatric surgery, which has been shown to be an effective way to both lose weight and maintain weight with time, with studies showing maintained weight loss for up to 20 years, and beyond.
The three most common procedures worldwide are the gastric band, the sleeve gastrectomy, and the Roux-En-Y gastric bypass. These procedures will require lifelong follow-up, especially nutritional supplementation for the rest of the patient’s life, and it is very important if patients are considering bariatric surgery (which has been shown to be very successful in remission of many of the comorbidities that I’ve written about so far) that they are assessed by an obesity physician to discuss the pros and cons of surgery and whether it is suitable for them.