Obesity is in the genes, but….


Scientific American reports the results of a study into the effect of genes and exercise on body weight.  It is confirmation of something that I think we all knew, which is that some people just put on weight more than others.  They just have obesity genes. Researchers have been able to identify some of the genes involved.  But it turns out that even people with this predisposition to obesity are still pretty trim if they get enough exercise.

One interesting point that comes out of studies like this is that although exercising will certainly burn up the body’s fat reserves – this in itself isn’t enough to lose weight.  The point is you have to exercise and not replace the calories that you have just burnt up by simply eating more.  And this is pretty much what your body will instantly tell you to do.  In fact I often wonder if there is an analogy between fast food and exercise.  The problem with fast food is not really the food itself, but the way we eat it and the way it enables us to pump a pile of carbohydrate straight into our blood stream at short notice.  This leaves the body with the problem of responding to what is in effect a shock to the system.  Sudden and prolonged exercise might well have the oppisite effect, depleting sugar from the bood rapidly.  If we then knock back an ‘energy drink’ (i.e., a high sugar drink) or a sandwich or the like we will have undone the entire point of the exercise.   It is quite frightening to consider the calorific value of a lot of what we eat.  To burn up the equivalent energy of a Mars bar might well take an hour of running, so if you are relying on exercise to lose weight you could easily lose the benefit with a fairly minor amount of extra snacking.

Maybe that’s why so many of us take so long to lose any weight through exercise, although no doubt we all feel much better for it.   I haven’t done any trials on this myself yet, I am not really overweight, but I wonder if it would be more effective to exercise more gently, perhaps just a walk rather than running or swimming?  And maybe a few shorter sessions rather than one long one?

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