This blog was written by Dr Katarina Kos, a senior lecturer in The University of Exeter Medical School. Dr Kos’s work looks at adipose tissue physiology and obesity related disorders.
In this blog post, she looks at what makes us eat the food we know will be bad for us.
The Forum will be broadcast on the BBC World Service between 4 – 7 April and you can download the episode on The Forum’s webpage.
Following an interview with the BBC World Service ‘The Forum’ programme, I was reminded of the burning issue of obesity and our relation with food. The theme of the programme was ‘dependency’, which I discussed in connection with my clinical work as a physician and my research into obesity and diabetes. Taking part made me think about communicating my work in a new light, and I wanted to share some of my thoughts about our bodies’ dependency on calories and how this relates to spiralling obesity.
To introduce myself, I am a fat endocrinologist. This not literally (I do everything possible to avoid being fat), but by the study of fat tissue. I work on increasing our understanding of the way fat/adipose tissue changes and responds to surplus calories, and how it contributes to ill health such as diabetes and heart disease. I also treat patients with weight problems who are preparing for weight-loss surgery, and patients with diabetes.
More than a quarter of adults in the UK are obese, as defined by a body mass index above 30kg/m2 if we are Caucasian or above 27.5kg/m2 if we are of Asian origin. Worryingly, this is predicted to rise to half the UK population by 2050.
The health risks of obesity are cardiovascular disease, cancer, stroke, dementia, diabetes, arthritis, and infertility. Whilst we are generally aware that surplus calories make us fat, what makes us eat them? And what specifically makes us overeat? This is a question I typically pose to patients at the beginning of my consultations, and the theme of dependency is prominent in their answers and my observations.
Physiological energy dependency
We have to eat to survive. As we evolved through history, people with genes which predispose to obesity had a survival advantage by being able to survive famines. Scientists believe that this ‘thrifty gene’ make up is, in part, responsible for the increasing obesity epidemic becoming more noticeable in times of energy surplus.
The concept of “food addiction” is controversial, but if we accept this idea then we are faced with the difficulty that, unlike in any other addiction, we cannot avoid contact with the ‘substance of addiction’, we cannot stop eating and survive.
However, most people with severe obesity do not eat because they are hungry.
Emotional dependency to calories
Most people with severe obesity eat because they are stressed or feeling low, feeling lonely, or for comfort. Our brain reward and pleasure centres, such as the hippocampus and striatum, respond to calories by releasing ‘happy hormones’, particularly if we eat sugar.
This helps to achieve short term gratification and is used as an emotional coping mechanism. A very memorable comment from one of my patients was: ‘food is my friend and you want to take my friend away’. Thus, for many who look into weight loss, the first step should include identification of any emotional eating patterns and finding solutions in how to deal with the emotional needs such as stress and loneliness.
With food being so easily available and its acquisition hardly requiring any physical energy expenditure (from internet shopping to freezer and then microwave) the emotional fix with food or drink, including alcohol, can be detrimental to the waist line of many people. Disconcertingly, in our current time of austerity, which translates to many people as financial hardship, we observe an increased popularity of baking and comfort food. Given people’s sensitivity about their weight and the stigma of obesity with the embarrassment and shame it brings to the affected, we can easily imagine why some unfortunate people chose social isolation with food remaining one of their very few friends.
Cultural dependency on calories
Calories are an easily available and most popular treat. We bring food or drink along when we see friends and cannot party and celebrate without calories. Not serving food or drink to a guest is an insult to hospitality. In some countries obesity is not a social stigma, but is seen as sign of prosperity.
As we are all prone to conform to social norms to the amount we eat and what we should look like (and most adults are overweight or obese -more than 60% in the UK), a diversion from these social norms will make us subject to social pressure. With this in mind, when trying to lose weight it is not easy to stick to a diet plan and work on a healthy lifestyle with social norms and our friends threatening to boycott our best intentions.
Let’s consider the moral and ethical dilemma this brings: do you serve a chocolate cake to your overweight friend because he/she likes it? Do you still do it if you know your friend is trying to diet and lose weight or has diabetes, and what if it is a birthday? Do you gain satisfaction in seeing a lovely big smile on your friend’s face when indulging with the cake? Alternatively, are you prepared to risk a conflict, be a spoil sport and remind your friend about health issues of obesity such as diabetes, all because you care? (..and do your decisions depend on your own success/failure with calories?)
My research is into fat (adipose) tissue which is the culprit of obesity and obesity associated complications such as heart disease and diabetes. Energy surplus leads to deposition of superfluous energy in form of fat packed in cavities of fat cells within fat tissue. With overnutrition fat tissue becomes overworked and its storage capacity limited. It develops inflamed and scarred which makes the tissue rigid and further restricts fat cells expansion. As fat tissue is increasingly unable to deal with the demand and storage of surplus energy, fats are deposited instead within and around organs.
Examples are the fat deposition in the liver causing fatty liver disease, fat in and around the heart causing weakening of the heart muscle and surplus fat within the vascular walls of the arteries contributing to heart disease, stroke and dementia. Fat is also increasingly found in the skeletal muscle which is not specific to us humans as we may more or less consciously observe in the mottling in the muscle/meat of the breakfast bacon.
One of my biggest contributions in research is the characterisation of a specific factor called SPARC which contributes to the scarring of human fat tissue and the cross talk of fat hormones with the brain. I continue to study the role of the scarring of fat tissue in obesity and its role in obesity complications. Losing weight is tough, I believe the body tries to hang on to fat tissue as much as it can. It is part of my research to understand why, from the fat tissues perspective, this is so difficult.
More research is needed to help and identify how to keep us at least healthy as we gain weight if not help us to lose weight. However, there are no obesity charities and obesity research funding is difficult to find. Funding undernourishment is compassionate. With the WHO reporting that most of the world’s population lives in countries where overweight and obesity kills more people than underweight, why is obesity research funding so difficult to obtain?
You find more on my research on my staff profile.
In summary, we must eat to function and survive; we tend to use food as an emotional crutch. Serving food and eating helps us to conform to societal pressure and cultural expectations which allows us to be nice people and avoid conflict.
On a personal note, as I work in weight management my workplace is often devoid of cakes and chocolates. But when they do appear, despite the fact that I’m immersed in the latest research and know that I should avoid them, I can’t always resist. We are all just human.