How hungry you feel, and how much energy you have available when you are running are both strongly linked to blood sugar levels.
Quick hits of simple carbs, like sugars, white bread, cakes etc. will cause your blood sugar level to boost quickly. OK during a run to keep you going, but this can be a problem before exercise or at lunch. The problem is that the body controls blood sugar levels with insulin and it is a not a very clever process: when blood sugar levels get too high, insulin is produced in such large amounts that instead of reducing blood sugar levels to a sensible level, they crash through the floor. This is why we feel sleepy after a big meal and why we get hungry after a few beers. You are bang on with eating breakfast. You should try to include some protein (e.g. nuts or an egg) in your breakfast and try to have wholegrains for carbs (oats / porridge is excellent), as this leads to a slow, controlled release of energy and maintains blood sugar at the correct levels for longer - you'll be alert and you won't get hungry so quickly. You should look at lunch in a similar way. All the carbs in the fruit you are eating are relatively simple, mainly sugars. Now, the actual amount of sugars is not too great, afterall we know fruit is much lower in calories per portion than cake! However, the sugars are quickly digested and thus cannot give you the sustained energy levels you need. This is why you are starving later. The solution is to eat a bigger lunch, keep the calories low, but not too low and avoid white bread, sugar etc. Eat more beans, chick peas, vegetables, white meat, fish, wholegrains, nuts and seeds but keep an eye on the calories. You still have to remember that CALS IN - CALS OUT = FAT. Oh, and caffein, being a stimulant, will increase adrenalin levels, which increases blood sugar and hence insulin levels, ultimately giving too low a blood sugar level; so, lots of coffees will make you hungry later. This should get you through most of the day without leaving you starving. A mid afternoon snack if a piece of fruit or some veg's will keep you going until run time. Then just before the run, go for some of the snacks suggested above. I prefer the slower releasing energy options - sunflower seeds or nuts. The other advantage is these contain protein which, when taken before and after exercise, helps strengthen and build your muscles. And muscles burn fat. By the way, I must emphasise that I am not a nutritionalist, but I have recently had a few consultations with one. It was well worth it and I have subsequently hit PBs on most of my regular running routes. Could be worth a try. A web page that may help: http://www.bupa.co.uk/health_information/html/healthy_living/lifestyle/diet/burn.html
Posted: 31/08/2006 at 10:08