With the new year there is plenty of advice on how to watch your weight, and as with every year, there’s a liberal sprinkling of myths. It can be hard to know what’s myth and what’s not. Here’s one of the perennials:
do we mistake thirst for hunger?
“9 Rules That Make Any Diet Work Better” in Good Housekeeping’s February 2017 issue says:
“the parts of the brain that deal with the sensations of hunger and thirst are very close to each other, so it can be easy to confuse one with the other”.
I’ve heard it said so many times in the past by my clients, and in the media, that we can confuse thirst for hunger. I wasn’t sure this was right so a couple of years ago I looked into this. I turned to the writing of Barbara Rolls, Professor of Nutrition at Pennsylvania State University and past-president of the Society for the Study of Ingestive Behavior.
Professor Rolls has spent her academic life researching thirst and hunger. She says,
“You see it all the time in tips for dieters: ‘You may be eating because you are thirsty, not hungry’. We’re sceptical. The body senses hunger and thirst through separate mechanisms… Because hunger and thirst are controlled by different mechanisms, it is unlikely that you are eating more food because you are thirsty” (The Volumetrics Weight Control Plan, p 108*)
Drinking liquids can temporarily reduce hunger
Although hunger and thirst don’t get confused in the way implied in the quote, drinking liquid causes stretching of the stomach in the way that eating food does, so that when you drink, your stomach tells your brain that something has arrived. Stomach-wall-stretching is one of the mechanisms the body has to signal to the brain what is going on the gut. So when you drink, the brain receives messages that something has entered the stomach, and this can provide a temporary reduction in feelings of hunger. But this isn’t anything to do with feeling thirsty and interpreting that as feeling hungry.
*Rolls, B. and Barnett, R.A. The Volumetrics Weight Control Plan (2000) Harper Torch USA
Dr Helen McCarthy
Associate Fellow if the British Psychological Society
Founder of Appetite Retraining www.theappetitedoctor.co.uk