Fat Substitutes: Do They Cause Weight Gain?
A study published in the June 20, 2011, issue of Behavioral Neuroscience found the following:
“Food intake, body weight gain, and adiposity were greater for rats that consumed both the high-calorie chips and the low-calorie chips with olestra compared to rats that consumed only the high-calorie chips, but only if the animals were also consuming a chow diet that was high in fat and calories. However, rats previously exposed to both the high- and low-calorie chips exhibited increased body weight gain, food intake, and adiposity when they were subsequently provided with a high-fat, high-calorie chow diet suggesting that experience with the chips containing olestra affected the ability to predict high calories based on the sensory properties of fat.”
Laboratory rats were fed either a high-fat or low-fat diet of chow. Half of the animals in each group received regular potato chips, and the other half received regular potato chips and lite potato chips made with olestra. The chips were provided for 28 days before switching the animals in the low-fat chow group to the high-fat chow maintenance diet for 16 days with no potato chips provided. When the animals were given both the high-fat and the low-fat chips, they gained weight on the high-fat diet, regardless of whether the low-fat chips were given to them before or during exposure to the high-fat maintenance diet. The rats fed a low-fat diet did not gain a significant amount of weight from either type of potato chips.
An alternative hypothesis that the animals fed both types of chips ate more as a result of increased sensory variety is unlikely. The animals fed a standard chow diet, low in sensory cues associated with fat, did not gain weight when given both high-fat and low-fat chips. Furthermore, animals given both types of chips did show significantly greater weight gain and increased adiposity when given a high-fat maintenance diet with no chips. Animals did not lose the gained weight when they were no longer given the chips. Animals who were switched from the low-fat chow diet to the high-fat chow diet after receiving chips gained more weight than animals that were maintained on the high-fat chow diet.
Previous studies have likewise shown that people consuming high-intensity calorie-free sweeteners have an increased risk of overweight, obesity, and health problems associated with excess weight, such as diabetes mellitus and metabolic syndrome. The taste of sugar and fat signals animals that a food is high calorie. Many responses are generated from the sensory experience of tasting something sweet, including salivation, secretion of hormones, and metabolic and thermic responses, which prepare us for the arrival of calories in the gut. These responses promote efficient energy utilization. Therefore, it is hypothesized that sweeteners and fat substitutes lead to the dysregulation of energy balance, because our learned associations are harmed and the ability to respond physiologically is perhaps weakened.
References and recommended readings
American Psychological Association. Fat substitutes linked to weight gain.
Available at: http://www.apa.org/news/press/releases/2011/06/fat-substitutes.aspx.
Accessed July 5, 2011.
Neubert AP. Study: trying to lose weight? Lose the fat substitutes.
Available at: http://www.purdue.edu/newsroom/research/2011/110621SwithersObesity.html.
Accessed July 5, 2011.
Swithers SE, Ogden SB, Davidson TL. Fat substitutes promote weight gain in rats consuming high-fat diets. Behav Neurosci. 2011;125:512-518.
Review Date 10/11