Artificial sweeteners have been sold as a guilt-free way to satisfy our sweet tooth. Sugar substitutes trigger our taste buds but pass through our body, virtually unabsorbed. The label “zero calories” on that cool can of Coke almost reads “go ahead, drink all you want.” And so we chug with the belief that the zero-calorie drink will provide caloric balance to that heap of chilli cheese fries. Not so fast, according to a recently published study from the University of Southern California. Drinks that contain the artificial sweetener sucralose may increase food cravings and appetite in certain people.
The artificial sugar - weight management controversy
There’s a bit of controversy surrounding the role of artificial sweeteners in weight management and weight loss. In theory, eating food and drinking beverages with artificial sweeteners should help with weight management. But there’s evidence to suggest that the lack of calories in artificial sweeteners fails to trigger the “I feel full” signal in our brain and may lead to increased appetite and cravings for sweets. And there’s also evidence to suggest that artificial sweeteners do not affect appetite or calorie intake from other foods. To confuse the matter further, when researchers investigate the role artificial sweeteners may play in weight management, some studies find a positive correlation between use of artificial sweaters and increased body weight while others conclude that the use of artificial sugars can be helpful in weight maintenance or weight loss particularly in obese individuals.
The paper published on September 28, 2021 in JAMA Network sought to understand some of the demographic factors that may influence the conflicting findings in the artificial sugars-weight management debate. This study focused on sucralose, a minimally absorbed sugar molecule with chlorine atoms attached that is 600 times sweeter than table sugar. During the course of three visits, 74 participants drank a drink sweetened with table sugar, a drink sweetened with sucralose, or water as a control. Following each drink, participants had their brain imaged in response to pictures of food items, and had measures of blood sugar as well as hormones in their blood taken. Two hours after each drink session, participants were given a snack buffet and the amount of food consumed was recorded.
The study found that women and obese individuals may be more sensitive to lack of satiety signal from artificial sugar. In particular:
Women and people who were obese showed more activity in regions of the brain responsible for food cravings in response to food images after drinking sucralose-containing drink when compared to drinks containing table sugar.
There were decreased levels of satiety hormones after drinking the sucralose-containing drink compared to the table sugar drink. This suggests that artificially sweetened drinks may not be effective in providing the “I feel full” signal.
Women and obese individiuals ate more at the snack buffet after drinking the sucralose beverage than after they drank table sugar beverage. This difference in consumption was not seen among men.
Consume with a grain of … sugar?
This finding from the University of Southern California provides interesting insight into differential neurohormonal response to artificial sugar by sex and body mass index. The conclusions require further investigation. It is unclear if the findings are applicable to other artificial sweeteners. In addition, participants in the study were subject to a 12 hour fast; It is difficult to apply findings following a 12 hour fast to general eating behavior. Moreover, the food buffet was provided 2 hours after the drinks were given; In real life, people drink and eat whenever they please, so there remains gaps in understanding the food cravings and intake at any time interval between drinking the artificially sweetened beverage and food consumption. Finally, this was a short-term study which was not designed to address the long-term clinical outcomes of using artificial sweeteners. Nevertheless, these findings provide plenty of (sugary) food for thought.
Sources:
Yunker, A.G., et al. (2021) Obesity and Sex-Related Associations With Differential Effects of Sucralose vs Sucrose on Appetite and Reward Processing A Randomized Crossover Trial. JAMA Network Open. doi.org/10.1001/jamanetworkopen.2021.26313.
https://familydoctor.org/sugar-substitutes/
https://foodinsight.org/everything-you-need-to-know-about-sucralose/
Tandel K. “Sugar substitutes: Health controversy over perceived benefits” J Pharmacol Pharmacother. 2011 Oct-Dec; 2(4): 236–243.
Blackburn GL et al. “The effect of aspartame as part of a multidisciplinary weight-control program on short- and long-term control of body weight” Clin Nutr. 1997 Feb;65(2):409-18.
Raben A. et al, “Sucrose compared with artificial sweeteners: different effects on ad libitum food intake and body weight after 10 wk of supplementation in overweight subjects” Am J Clin Nutr. 2002 Oct;76(4):721-9.
Yang Q. “Gain weight by “going diet?” Artificial sweeteners and the neurobiology of sugar cravings”Yale J Biol Med. 2010 Jun; 83(2): 101–108.
Smeet PA et al. “Functional magnetic resonance imaging of human hypothalamic responses to sweet taste and calories” Am J Clin Nutr. 2005 Nov;82(5):1011-6.
Rogers PJ et al “The effects of low-calorie sweeteners on energy intake and body weight: a systematic review and meta-analyses of sustained intervention studies.” Int J Obes (Lond). 2021 Mar;45(3):464-478.
Catenacci VA et al, ”Low/no calorie sweetened beverage consumption in the National Weight Control Registry.” Obesity (Silver Spring). 2014 Oct;22(10):2244-51.
Fowler SPG. “Low-calorie sweetener use and energy balance: Results from experimental studies in animals, and large-scale prospective studies in humans.” Physiol Behav. 2016 Oct 1;164(Pt B):517-523.
Azad MB et al. “Nonnutritive sweeteners and cardiometabolic health: a systematic review and meta-analysis of randomized controlled trials and prospective cohort studies.” CMAJ. 2017 Jul 17;189(28):E929-E939.