Over the next few weeks, we’ll be posting 10 myths about dieting from the article by Michael Mosley in The Times.
Claim 6. If you stop eating for a while then your blood sugar will fall dramatically and you will faint.
In the trial I mentioned in the previous post, Resting energy expenditure in short-term starvation, they also measured the volunteers’ blood glucose levels. They found that their blood glucose levels did slowly fall over the three days, from 4.9mmols/l on day one to 3.5mmols/l by day 4. These, however, are the sort of levels you might expect to see in a healthy individual who had their blood taken before breakfast . They are not, in any sense, abnormally low.
At the same time the levels of fatty acids in their blood shot up, showing that their bodies had switched into major fat burning mode.
Your body evolved to cope with periods without food. Modern humans, however, are used to eating lots of regular meals and there is evidence that the hunger hormone, ghrelin, rises simply in anticipation of a meal. Intermittent fasting can be tough, but there is no evidence it is will cause you to faint.
12:41 pm
7 Jul 14