January 12, 2017
So far I still have seen/heard nothing on TV/newspaper/radio to tell me about obesity awareness week!
But I am blogging on it.
So – why is obesity such a problem?
We all know the health effects – but why does a bit of extra fat cause so many problems?
The quick answer is that too much body fat takes on a bit of a life of its own with all sorts of knock on effects, including type 2 diabetes (T2D) and cardiovascular disease (CVD), which have been the target of much scientific research to try and nail down exactly why.
So here are some of the questions and current thinking…
Does body shape matter?
You may have heard of apple (android) shape being more of a risk than pear (gynoid) shape. These terms refer to whether excess body fat is stored around your middle (android/apple) or on your bottom (gynoid/pear) – and some of this is due to your genes – so hard to change – blame your ancestors!
The fat on your bottom (gynoid – pear shaped) is mostly as a layer under your skin (subcutaneous) and therefore spread out over a wide area.
The fat around your middle is under your skin as well but is also packed in large blobs around internal organs such as the intestines, kidneys, heart etc. On the outside, it becomes ‘the beer belly’ and can be seen escaping over the top of trousers, hanging over belt buckles in extreme cases and popping buttons. Women can be apple or pear shapes – men are usually apple shaped.
This apple/android shape with its central / abdominal / tummy fat deposits is associated with increased risk of CVD, T2D and some cancers.
So why should this android shape be such a problem?
The fat deposits can be quite large and fat cells are pretty lazy – if you look at them under a microscope they are cells that look like a big globule of fat. Like most other cells they have a nucleus and a few other cell organelles for general maintenance. But they are metabolically relatively inactive – on ‘tick over’ – when compared with very busy muscle cells (lean tissue) which need a lot more energy to survive.
The blood supply to fatty tissue is nowhere near as extensive as that to lean tissue – doesn’t need to be as fat cells need less in the way of oxygen and nutrients for their sluggish lives compared to lean, mean muscle cells which might suddenly be called upon to perform at top speed.
And now some information about inflammation…
Chronic, long term disease such as CVD or T2D are associated with what we call a state of ‘chronic low grade inflammation’.
‘Chronic’ means long-term, ‘low grade’ means mild and ‘inflammation’ is the natural protective defence our bodies normally use to protect us against attack from invaders or injury. The inflammatory response occurs when our body cells start sending out ‘help’ messages to their cell friends which in turn recruit help from all those specialised response systems geared up to protect us when needed. But this protective response should be a short term helpful response which ends once the foe is vanquished and the body is repaired.
What does this mean for fat deposits?
There is some thinking that the large fat deposits in abdominal cavities may suffer from lack of oxygen due to the relatively minimal blood supply in the centre of such big deposits. Cells need oxygen – and when deprived they start complaining and sending out help messages – ‘we’re suffocating in here’ – which provoke an inflammatory response and the release of chemicals from other cells keen to help repair damage. We know this because blood samples show higher levels specific chemicals (called ‘markers’) known to be involved in inflammation.
The problem is that the foe is those fat deposits and cannot be vanquished and therefore keeps sending out more and more help messages – the normally helpful chemicals continue to circulate in our blood but end staying for far too long as continually topped up – causing damage because of their long term and continual presence.
There are many other complex processes involved and many theories offering further explanation. But in the end it is clear that a chronic low grade inflammatory response is undesirable and counterproductive to health.
It can eventually result in disease states such as T2D and CVD.
And what happens if we reduce those fat deposits?
Reducing the size of fat deposits by losing weight, or even liposuction, means the oxygen and nutrient supply problem is reduced or even resolved. Blood samples have shown that the levels of inflammatory markers – those chemicals in the blood described earlier – reduce, can even revert to normal, indicating that the chronic low-grade inflammatory state has been ‘turned off’.
And all of the above can help explain why reducing fat deposits can reduce the levels of inflammatory markers which in turn has a beneficial impact on those chronic diseases.
If those large masses of fat with their bevy of complaining cells no longer exist – there can be no help messages being sent out and therefore no response forthcoming.
Sue Force, Mission4Nutrition