New research by the Smart Food Centre at the University of Wollongong has discovered a solid serving of vegetables is one of the best ways to control your weight. However, the finding applies only if vegetables are eaten in chunks or slices. Pureed, juiced or mashed vegetables are less effective in warding off hunger pangs.
The weight control benefits of vegetable consumption are not a direct result of their low calorific and high vitamin content, but relate instead to a secondary attribute of all vegetables -- they make one feel very full or satiated.
The Smart Food Centre, using funding provided by vegetable growers through a production levy, is investigating if some vegetables are more effective than others in combating obesity.
It is also researching if raw or cooked vegetables offer different weigh-control benefits or if the form in which they are consumed -- shredded, diced or sliced -- affects how quickly appetite returns. Early findings from a study in which University of Queensland students were given large servings of carrots mixed with pasta for breakfast and lunch show there is little difference between raw, steamed or cooked carrots in inducing a sensation of fullness. But pureed carrots are not nearly as effective in delaying the return of hunger and thus the potential to overeat.
Researchers from the Smart Food Centre believe pureed food is less effective in making vegetable eaters feel as full, and does so for a shorter time after the meal, because less chewing energy is required and the meals are eaten much more quickly.
"The nature of fruits and vegetables make them excellent satiating agents that could promote feelings of fullness whilst minimising energy intake during a meal," said researcher Kelly Boulton. "Their freshness and tastiness also lessens the boredom of eating (while) the presence of dietary fibres in fruits and vegetables induces thickening and the formation of gel-like structures when in contact with liquids, thereby increasing the stomach distension and leading to prolonged sensations of fullness."
Andrew While, spokesman for the Ausveg producer organization, said its 9000 growers were delighted to discover the positive additional role played by vegetables in controlling weight and helping prevent obesity.
"If you feel full you are less likely to overeat," White said.
"Researchers also commented that vegetables may be the ideal food group for promoting satiety due to a generally low energy density, high levels of swellable fibre and diverse phytochemical contents."
From the March 30, 2012, Prepared Foods’ Daily Update
