JAMA questions sense of sweeteners for weight loss

Low-calories sweeteners are used in products including beverages, biscuits, cakes and confectionery intended to meet consumers' desire for sweet treats but, at the same time, deliver less calories. This strategy has become especially important given the food industry's efforts to help curb the current obesity crisis. A recent report by Freedonia revealed that the US sweetener market alone is poised to increase 4 percent per year at present, to reach over $1bn in 2010. The feature, which appears in the Journal of the American Medical Association (JAMA), gives a roundup of recent research into the how useful sweeteners could really be in addressing the current obesity crisis. "Although low-calorie sweeteners are a dietary staple for many individuals trying to maintain or lose weight, am emerging body of evidence suggests these substances offer little help to dieters and may even help promote weight gain,"​ wrote author Tracy Hampton, PhD. To support her argument, Hampton cites a 2007 review of laboratory, epidemiological and clinical studies examining the effects of low-calorie sweeteners (Bellisle, Drewnowsku, 2007), which she said "presented an unclear picture of their usefulness". Notably, "there is currently no official recommendation about using artifical sweeteners as a tool for weight control"​ - even if that is the tack often taken by food and beverage manufacturers and the understanding of consumers. One of the most interesting areas of study at present is the brain response triggered by sweeteners, as opposed to sugar. A recent study published in Neurimage​ (Frank GK at al) used functional magnetic resonance imaging to look at the brains of women as they ate sugar, and as they ate sucralose. The found that sugar better stimulates areas of the brain related to expectation and desire. The result is that the thought of sweeteners actually lessens the desire for sweetness. In addition, the authors proposed that the lack of feedback from the brain that results in satiety could lead the consumer to over-eat. Hampton said that other (uncited) studies have concluded that low-calorie sweeteners could increase appetite for sweet foods, this prompting over-eating. She said they may "blunt the body's energy expenditure mechanisms and activate taste pathways different than sucralose - findings that might prompt dieters to rethink their weight loss strategies".​ Earlier this year researchers from Purdue University reported on findings that male rats fed yoghurt sweetened with glucose or saccharin were seen to gain body weight and body fat. "The data clearly indicate that consuming a food sweetened with no-calorie saccharin can lead to greater body-weight gain and adiposity than would consuming the same food sweetened with a higher-calorie sugar,"​ wrote Susan Swithers and Terry Davidson in the journal Behavioral Neuroscience​, published by the American Psychological Association (APA). Sources: Journal of the American Medical Association ​May 14 2008, Volume 299, No 18, doi: 10:1001/jama.299.18.2137 "Sugar substitutes linked to weight gain" ​Author: Tracy Hampton European Journal of Clinical Nutrition​ Volume 61, Pages 691-700, doi:10.1038/sj.ejcn.1602649 "Intense sweeteners, energy intake and the control of body weight"​​Authors: F. Bellisle and A. Drewnowski Neurimage ​2008; 39(4): 1559-1569 ​"​Sucrose activates human taste pathways differently from artificial sweetener.​Authors: Frank GK, Oberndorfer TA, Simmons AN, Paulus MP, Fudge JL, Yang TT, Kaye WH ​Behavioral Neuroscience​ February 2008, Volume 122, Number 1, doi: 10.1037/0735-7044.00.0.000 "A Role for Sweet Taste: Calorie Predictive Relations in Energy Regulation by Rats"​ Authors: SE Swithers, TL Davidson