Stay off that white bread and dig into that apple or lentils, for a new study has found that foods like the latter that release energy slowly once they have been consumed helps dieters lose more weight than those more likely to spike blood sugar levels.
Foods that release sugars rapidly are said to have a high glycaemic index - those that release it slowly have a low glycaemic index, and Cochrane researchers led by Dr Diana Thomas, the Scientific Director of the Centre for Evidence Based Paediatrics Gastroenterology and Nutrition, in Westmead, Australia conducted a review of studies that looked at the effects of eating high and low glycaemic index foods.
They found six randomised controlled trials that involved a total of 202 participants from Australia, France, South Africa, Denmark and the United States. The trials ran for between five weeks and six months.
Their conclusion was that people eating low glycaemic index diets lost a mean of one kilogram more than those on similar energy high glycaemic index diets.
Low GI dieters also experienced greater decreases in body fat measurements and body mass index.
None of the studies reported adverse effects associated with consuming a low glycemic index diet.
"Low glycaemic index diets appear to be particularly effective for people who are obese," says Dr Diana Thomas.
"It may be easier to adhere to a low glycaemic index diet than a conventional weight loss diet, since there is less need to restrict the intake of food so long as the carbohydrates consumed have a low glycaemic index," says Thomas.
Added review co-author Elizabeth Elliott, Ph.D.: "Losing weight is very difficult and many people are unable to sustain a weight-loss diet. The low glycemic index diet is satisfying and has proven benefits".
"Compared to other diets, the low GI diet is more satisfying - people are less inclined to feel hungry. One advantage of this type of diet is that it is more likely to be maintained than other strict diets on which people feel hungry," Elliott, a professor at the University of Sydney, The Children's Hospital at Westmead, added.
Low glycemic index diets might also benefit heart health.
In the three studies that measured cardiovascular risk factors, people eating low GI foods experienced greater improvements in total blood cholesterol and low-density lipoprotein (LDL) - sometimes called "bad" cholesterol. High levels of total cholesterol and LDL cholesterol increase the risks for heart disease.
After reviewing the findings, Lawrence Cheskin, M.D. said, "There's surprisingly little in the way of studies to draw any hard and fast conclusions."
Cheskin is director of the Johns Hopkins Weight Management Center and associate professor at Johns Hopkins Bloomberg School of Public Health in Baltimore. He was not involved with the review.
The review appears in the latest issue of The Cochrane Library, a publication of The Cochrane Collaboration, an international organization that evaluates medical research.