Science reveals how soup helps tame appetite
Eating soup can help you lose weight and is dieting’s best kept secret according to science writer and author of the website explaining-science.co.uk, Jack Challoner.
He explains that blending food and water to make soup keeps you hunger-free for longer and makes you less likely to snack through the afternoon.
The secret to this lies in the stomach. Scientists have used ultrasound and MRI scans of people’s stomachs to investigate what happens after eating solid-food-plus-water meals compared with the same food made into soup.
After you eat a meal, the pyloric sphincter valve at the bottom of your stomach holds food back so that the digestive juices can get to work. Water, however, passes straight through the sphincter to your intestines, so drinking water does not contribute to ‘filling you up’.
When you eat the same meal as a soup, the whole mixture remains in the stomach, because the water and food are blended together. The scientists’ scans confirm that the stomach stays fuller for longer, staving off hunger pangs.
This is because a hormone called ghrelin which makes you feel hungry is released by cells in the stomach wall. But whenever the stomach wall is stretched – when the stomach is full – the cells stop producing ghrelin, turning off the appetite signal. The longer the stomach remains full, the longer you feel satisfied and the less you are likely to eat.
Finding ways to control the appetite signal is crucial to stave off the meteoric rise in obesity. In 2006, scientists at the Scripps Research Centre in the US developed a vaccine to counteract the influence of ghrelin, in an attempt to control appetite.
It is still undergoing clinical trials – so for now, the best and simplest way to keep hunger at bay is to blend your food into a healthy, voluminous soup. The best sort? Vegetable soup, as it produces a more consistent blend and is generally lower calorie than chicken or fish soup.