Getting fatter, trying to get thinner – obesity is complicated.
“The no hunger diet”….“The last diet you will ever need”… “Eat your way thin”….these and other phrases are things we have read and heard for decades, and yet overall the population is getting bigger. There are now more adults in the UK with overweight and obesity, than without. Those with overweight and obesity are hugely familiar with the pattern of making a huge effort and losing weight, followed by regaining, with a little bit extra for good measure. This often happens repeatedly over years. The psychological impact of this is significant and harmful, with misplaced feelings of shame and guilt that people feel for not being able to keep that weight off.
For some people who have never developed overweight or obesity, the idea that you cannot just eat less and move more, to get and stay slim, is perplexing. It’s just physics, surely. Society has reinforced this message with discussions around bodyweight often focusing on willpower and determination, as if those with excess weight have somehow not got these things, that they are morally inferior to those with smaller bodies. Anyone who has ever lost significant weight will tell you that this couldn’t be further from the truth – it takes a huge and sustained effort to lose weight and it’s even harder to keep it off. This is because they are fighting their own bodies to do so. Luckily, we now have the science to explain this and we shall explore this further now.
Why does obesity happen?
The field of obesity medicine is rapidly expanding. We now know many of the factors that make someone more likely to develop overweight and obesity, and we are learning why only approximately 7% of people with obesity who manage to keep their weight off long term. Because this field of medicine is so new, this knowledge is not widely known yet, both within medicine and wider society, which is one of the reasons why the new medicines to treat obesity and overweight have had such a mixed response. Is it cheating? Is it not better to lose weight the “real” way? Should we be spending NHS money on those who should just try harder?
There are certain factors which will make someone more likely to develop obesity. Firstly, our genetics. Whilst it has always been accepted that some people are naturally slim, the idea that others are naturally bigger, has been dismissed. But it is true. We know that obesity runs in families and that the likelihood of developing obesity is, in part, controlled by our genes. These genes, amongst other things, affect our desire for food, the happiness we get from food, our behaviours around seeking out food and how our body behaves when we eat food. Think of the difference between someone who will forget to eat and someone who can’t walk past a bakery without being tempted - genes play a big part in this. It is also true that children born to parents (both mum and dad) who have overweight or obesity have a much higher chance of developing it themselves, due to the influence of these genes on the developing fetus, along with other factors.
After genetics, we need to consider the society and environment in which someone lives. Access to fresh foods and spaces to move are unsurprisingly important in preventing the development of overweight and obesity. However, there are other factors that play a huge part. Food poverty, financial difficulties, sleep problems and constant stress about housing or employment, will alter our stress hormones and mean that we may not be free to make choices that are good for our health. Our genes and our environment interact, to make obesity more likely.
Our psychological state, how much we are able to move, other medical conditions and medications that we may have to take also all play important roles in how likely we are to gain weight.
It is the action of hormones and chemical messengers that link our brain and our digestive system (the gut-brain hormonal axis), as well as those that come from fat tissue around our organs, that are now some of the most widely researched risk factors for obesity. And it is these areas that the new medicines for obesity are targeting. It is exciting and life-changing science that shows how the approaches to weight loss that have been thrown at us for decades were getting it wrong. It has also led to the understanding of how obesity leads to other diseases. The fat tissue around our organs, our visceral fat, secretes chemicals called adipokines, that cause inflammation in the lining of our blood vessels and lead to type 2 diabetes and liver disease as well as cardiovascular disease and other metabolic problems.
There are potentially hundreds of gut-brain hormones that are involved in the regulation of our bodyweight. If we think of the way that our body makes sure we have the right amount of fluid in our tissues or stays at approximately the right body temperature for our organs to function, our bodyweight should be regulated in the same balanced way, but it can more easily go wrong. And that is where the disease of obesity, because it is a chronic life-long disease, comes into play.
These hormones help us to know when we are hungry, when we need to eat, how much energy our bodies are using and what our organs need to do when we have eaten. They influence our appetite, how long food stays in our stomach and whether we get full from meals. In someone with obesity, these hormone signals are fundamentally changed, making the person feel more hungry and less full, all of the time. As someone with obesity loses weight, their body rebels further, and makes them more hungry and less full with every meal. Which is why managing to diet takes superhuman effort, you are literally fighting your biology.
To make it even harder, our body, particularly the genes within our fat cells, have a memory of where it wants our body weight to be. If we have gained weight (the exact change required to make this happen is still being researched) our body wants to us to stay at this new normal. So the “feeling hungry and less full hormones” like Ghrelin kick in, ensuring that we regain that weight, with just a bit extra in case we ever dare to try and do it again. Hence “yo yo dieting”. It isn’t that someone regains weight they have lost due to laziness or a moral failing, their body literally makes it happen.
The new obesity medicines – why are they so exciting?
The two most effective new drugs we have for obesity currently are semaglutide (wegovy) and tirzepatide (mounjaro or zepbound). These are drugs we have used to treat type 2 diabetes for some time, but were then found to cause weight loss as well. Semaglutide works by acting on the hormone GLP-1, which makes us less hungry and makes our stomach empty slower, thereby helping with control of our appetite. Tirzepatide does the same, but it also works on another hormone, GIP. At present studies are showing that Tirzepatide is leading to greater weight loss overall compared to Semaglutide but they are both very effective. Many other drugs are in development.
We will talk more about how the meds make people feel in the next blogs, but the one of the fascinating things are the effects that these medications are having on our health, other than on bodyweight. They reduce inflammation and cause improvements in conditions such as sleep apnoea, heart failure, metabolic liver disease, cardiovascular disease and kidney disease. These health gains are independent of weight loss – which remains truly fascinating and an area of research.
At Genwell, our detailed and expert knowledge of obesity and medicine, means that we understand and keep up to date with the science, and use this expertise to guide you on your weight loss and health gains. We know that you may have concerns regarding other medical conditions you have, and medications that you take, and we can ensure a safe approach to weight loss for you. We know that obesity and overweight are not your fault, we know that you are unique, and that the reasons for your weight gain are personal to you. We find out what have been the most significant factors for you so far in weight loss and gain. Via our holistic medical approach, we will use the right medication to help you achieve the health improvements and changes in your weight that are best for you now and in the long term.
