So this is a big topic which often has a range of interpretations attached, but the crux of it is – Is obesity a disease of the person, or is it a disease of our society?

Some people think it is just calorie in and calorie out and a dose of willpower – simple right?  That may be in a lab but in my experience of the real world it is vastly more complex than this, partly because of the unique biologies from our brain to our bodies metabolic and hormonal processes, but also because of the simple practicality of it all – our social lives, our cultures and our preferences are also very different from one another and hence the causes and treatments are wide-ranging as well. The vast majority of this series is about what you can do about it so I did the next few videos because I want to dispel the myths that I hear so often and highlight that there are many many contributors to being overweight, some we can control and some we cannot.

Focussing on our biologies for a moment and leaving the rest for the next videos; there is still a lot we don’t know and a lot that is debated. The science and interpretations get pretty heavy so I won’t go into too much detail on all of the various theories out there but I will highlight a few key principles to know about because in the end what matters is what we do about it. For example one theory is about the hormone insulin that stimulates fat cell storage after we eat food.  Insulin was thought to be only stimulated by carbohydrates in food but when we look at the studies we see insulin production is also from a range of protein and fat sources as well like cheese, milk and animal proteins and when we look at high-quality clinical trials comparing low carbohydrate diets to low-fat diets we see that there is no difference in the reduction of insulin scores. Hence in this specific example despite seeing a wide range of various theories it doesn’t actually change our path forwards that much, which is the whole point of this course; moving forwards.

Each of us is biologically unique, in our genes, in the way those genes are expressed called epigenetics, in the trillions of healthy bacteria that live on and in us called the microbiome.  We are learning more how different people respond very differently to the same foods, for example, I might eat some rice and be fine, but you might eat some and your sugars will go up really high.

But there are many other factors that may be responsible for our weight.  Some are things we cannot change. For example, there are at least 90 genes which we inherit from our parents that are related to being overweight, like the FTO gene.  Whilst having these genes make you more likely to be overweight, it actually does not mean you cannot lose weight. In fact, studies have shown that people with these genes can lose weight just as effectively as those without the genes.  Partly this is because of how the genes are expressed, called epigenetics. See genes can be switched on or off, and when we are physically active and eating well, it may be affecting the way these genes are expressed.

Other biological things that affect our weight can include how we were fed as an infant like whether we were breastfed or not, what happened to use whilst we were growing as embryos and fetuses and possibly specific types of infections.

There are also medical conditions like an underactive thyroid called hypothyroidism, Cushing disease, or polycystic ovarian syndrome and certain medications that may be contributing to your weight.  It might be helpful to discuss these with your doctor.

What else?  There is now interesting research going on in our gut microbiome which I have mentioned before.   There are 100 trillion good bacteria, fungus and virus happily living in our gut, mouth, lungs etc doing lots of good things for us like.  However, some also do bad things. We know that you can put the gut bacteria of a fat mouse, into a skinny mouse and make that skinny mouse – fat!  So we don’t know what to do with that information yet except to alter our food, because that is what feeds the bacteria and hence the bacteria change when we change our food and lifestyle choices.  But watch this space and I discuss this more in a later video.