The simple answer is YES, there are about 2.8 million adults per year that die from
being overweight or obese globally. Indeed being overweight and obese is the fifth risk
for global death. Most of this burden really comes from the diabetes that’s out there,
from ischemic heart disease associated with being overweight and obese, and of course,
increased risk of cancer associated with being obese.
There is a study called the Framingham Heart Study, and this shows that if you are obese
and a non-smoker, women lose seven years of life and men lose about six years of life,
but if you’re obese and a smoker, both women and men lose at least 13 years of life.
That’s quite significant.
Obesity can virtually affect every organ of
your body. We can try and look at the complications of obesity by splitting them up into three
sections—metabolic, mechanical, and mental. If we start with the metabolic complications
first, obesity is associated of course with a very high risk of type II diabetes which
leads to a real disease burden. Obesity increases your risk of cardiovascular disease, including
coronary artery disease, the risk of strokes, the risk of heart attacks,
dyslipidemia—that’s abnormalities with cholesterol, and increased risk of heart failure.
Obesity is associated with an increased risk of gallstones, fatty liver, which can progress
to fibrosis and cirrhosis, and of course, it may then lead to the need for liver transplants.
Currently, alcoholic liver disease is the major cause for liver transplants, but obesity,
fatty liver disease and progression of that is said to be probably the most common cause
for a liver transplant in the years to come. Obesity also affects respiratory disease.
We see increased rates of obstructive sleep apnoea in our patient population and also
exacerbation of asthma. Moving to other metabolic problems, of course
the increased risk of cancer is also increased in our population. This increases risk of cancers
such as breast cancers, colorectal, endometrial, ovarian, pancreatic cancers, amongst many others.
If we then move on to the mechanical complications of obesity, of course, we know that
an increased weight is associated with problems with lower back pain and osteoarthritis.
Finally, thinking about mental disease which
of course is a really, really important part of this triad of complications, we know that
many of our patients with obesity have depression and anxiety. Of course, this burden of disease
really needs to be tackled and sometimes it’s very much ignored when we manage our patients.
There are many options available for weight loss but the cornerstone of all these options, of course,
is lifestyle interventions, so dietary changes and increased exercise within our lifestyles.
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, our satiety hormones that speak to our brain to say 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 weight loss and maintaining weight loss although these procedures
are temporary and once the device is removed, then the satiety signal is 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 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 lifelong, and it is very important that if patients are
considering bariatric surgery, which of course has been shown to be very successful in remission
of many of the comorbidities that I’ve spoken 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.
Our bodies are designed in such a way as to preserve energy and defend us from 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 – that’s ghrelin — and to decrease our satiety hormones,
and 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; that is, 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. So, 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, in time.