I was planning to write this second blog post about measles (and other scary infectious diseases which we are starting to see again), but that seemed a bit miserable for the week after Christmas, so I’ve diverted to write about something more positive.
I realise that obesity doesn’t really sound like a cheerful topic, but actually it is a condition that is, always, totally reversible, making it a lot more positive than measles in my view. And, even better, relatively small amounts of weight loss can make a big difference to health outcomes: Information leaflets and public health campaigns generally quote values of around 5-10% loss of body weight in obese individuals as starting to make measurable improvements in cholesterol profile, blood pressure, and diabetes control. They less commonly mention the psychological benefits, but I know from talking to successful graduates of weight loss groups, or just grim determination to lose weight on their own, that there are usually massive psychological benefits, which can start with improved self-belief after just attending the first group or losing the first pound.
The World Health Organisation definition of overweight and obesity is ‘abnormal or excessive fat accumulation that presents a risk to health’. For practical purposes we need figures which we can all use to flag up weight issues. The body mass index (BMI) is widely used, calculated by dividing weight (in kilograms) by height squared (in meters). The desirable range is 18.5-24.9, with 25-29.9 described as overweight, 30-39.9 obese, and 40+ morbidly obese. In children age and gender come into play too, and you can find a calculator tool for both adults and children on the site https://www.nhs.uk/live-well.
Further prediction of how healthy our weight, but also fat distribution, is can be gained from measuring waist circumference. This takes into account the fact that storing our fat mostly around our internal organs (‘apples’ not ‘pears’ as women might know it, or ‘beer bellies’ as men might) is worse in terms of health outcomes than having the same amount but storing it mostly under the skin.
Now when I said in the first paragraph that obesity is always reversible this is undeniably, if uncomfortably, true – if you take all calories away from a person their body will rapidly use up the sugar stores (in the liver), then move on to the fat stores (internal around the organs, and external under the skin), and when those are gone it will use up protein (muscle), before eventual death from starvation. This will occur whether they are a diabetic, have an underactive thyroid, are on medications which promote weight gain, or come from a family that tend to be overweight.
If we can agree that weight loss is always possible, and that it is highly desirable for health not to be overweight, then why is it that so many people, medical professionals included, are obese? The phrase ‘it could be her glands’ is one I’ve heard repeatedly over the years. It isn’t her (or his) glands. An underactive thyroid gland can cause weight gain, but is corrected with thyroxine medication. And anyway, sufficiently low calorie intake will still lead to using up stored fat.
So if it isn’t ‘the glands’, what is the problem?
Well of course most of you are now shouting at the screen that it is too much food/drink and too little energy burned off by activity. And you are right! However, the processes underlying that statement are complex and our understanding is evolving. Scientists have discovered hormones, enzymes and neural pathways (nerve communications between parts of the brain, but also the brain and the gut) that weren’t even known during my time at medical school, 20 (ish) years ago.
I’ve done a lot of reading preparing this post, medical school having left me with gaps in the science here. And the more I’ve read the more dizzying the interactions between appetite, blood sugar, fat storage, exercise, digestion, insulin levels, heat generation, genetic make-up, ghrelin, and leptin (hormones I didn’t learn about at medical school) have become. These should all interact perfectly, as developed over the millennia by mother nature, so that our bodies remain a healthy weight. Much simplified, when we eat, the body tells the brain we are not hungry any more, and starts to use up the calories by making more heat, then storing what is left for later. If the stored fat starts to build up this sends messages to the brain to eat even less, the body uses up the fat instead, and everything stays in balance. BUT the more sugar we eat, the more insulin we need to deal with it. The more fat there is the more insulin we need to make our tissues absorb the sugars… but all that insulin has effects on the other hormones and pathways, in a bad way, so the brain stops listening to signals that we don’t need to eat more, and the system starts to get out of balance, and can spiral downwards with the excess fat making it harder to regulate everything else.
I said this was a positive post for the New Year, and I can leave you with a couple of really helpful conclusions from all that reading:
- Firstly, as you’ll be aware from the press, it is looking like sugar is the enemy here. And that is not just refined sugar, but also ‘white’ carbohydrates (pasta/bread/potatoes/rice) because they just turn into sugar on hitting the gut. This may be the easiest time of year to resolve to alter our diets, thanks to a combination of guilt and simply needing a change from the rich foods of the festive season. It doesn’t make it any easier to stick to the changes though. So, if you can, once the detox diets and resolutions have run their course, have an honest look at the amount of sugar creeping back into your life. Sadly it’s out there hidden in most packet foods/sauces, and white carbohydrates, as well as the obvious biscuits, cakes, sweets and puddings.
- Secondly, one factor keeps popping up as having an anti-obesity influence on all the different hormones and neural pathways. It can even reverse the imbalances that excess fat cells and sugar cause. Now that is surely fantastic news! So PHYSICAL ACTIVITY is a topic I’d like to come back to next month, and maybe I’ll feel inspired to make a February resolution…just in case the January one has wobbled off course by then.
For now I wish you a Happy New year.
By Dr Kate Roberts-Lewis