Soup has long been the friend of those who are trying to lose weight. Much research has confirmed that people who begin a meal with soup, consequently eat less calories at that meal than those who don’t eat soup and that they feel fuller afterwards. New research published in the January 2013 issue of the European Journal of Clinical Nutrition, which was published Jan. 10, has found out why. Soup raises increases the blood sugar more quickly than other foods, making sugar and other nutrients available to the body more quickly.
Researchers from the Functional Food Centre, Oxford Brookes University, Headington, Oxford, UK in conjunction with the Brenner Centre for Molecular Medicine in Singapore and the Physiology Department of the School of Medicine at the National University of Ireland in Galway studied 12 volunteers and their responses on three different occasions to three different types of meals – a typical solid meal, a chunky soup and a smooth soup.
The partipants then recorded how full they felt and had their blood sugar and the time it took their stomach to empty from the meal measured, using standard tests.
The smooth soup took the longest to leave the stomach, followed by the chunky soup with the solid meal taking the longest. The smooth soup had the greatest effect on blood sugar levels, raising blood sugar by an average of 87 mmol/l/minute, followed by the chunky soup at 65.4 mmol/l/minute and the solid meal coming in at 61.6 mmol/l/minute.
The researchers concluded that the smooth soup induced greater fullness compared with the solid meal because of a combination of delayed gastric emptying leading to feelings of gastric distension and rapid accessibility of nutrients causing a greater glycaemic response.y participants, in line with the findings of previous studies, reported feeling most full after the smooth soup than the other two meals.
This is something that people who are following a low carbohydrate diet should take into consideration when choosing the ingredients for their soups. Many people choose a low-carbohydrate lifestyle in order to minimise disruption to insulin and blood sugar levels. Eating smooth soups which have even a moderate amount of carbohydrate in them may be detrimental to blood sugar and insulin control, particularly if the soups contain ingredients like pumpkin, sweet potato or potato.
Part of the reason why soups help people to feel fuller after a meal is that they sit in the stomach for longer, making the stomach feel distended which triggers feelings of fullness and hormones associated with satiety. Another reason that they trigger a feeling of fullness is that the nutrients contained in the soup require very little digestion and are almost immediately available in the bloodstream. In some instances this is a good thing, and soups are definitely something that can easily play a significant part in a healthy, low-carbohydrate diet, just be careful to consider the glycaemic response when choosing ingredients.
Clegg ME, Ranawana V, Shafat A, & Henry CJ. (2013) Soups increase satiety through delayed gastric emptying yet increased glycaemic response. European Journal of Clinical Nutrition, 67(1), 8-11. PMID: 23093339