Sugar Substitutes: Fewer Calories, More Risks?
The action of replacing someone, or something, with another person or thing; this is known as substitution. It’s an often-used tactic in life that can improve workplace endeavors, create new solutions, and better human health. Substitution can take place in a high school classroom (a substitute teacher), or on the basketball court; maybe a coach decides his star player needs a break from the action, so he calls for a ‘sub’ to fill his role. Even more — substitution occurs at the dinner table, with health-conscious swaps between high and low-calorie alternatives. However, in all of these scenarios, the substitution comes to an end. Eventually, the hired teacher replaces the substitute, the star player checks back into the game, and occasional indulgences are allowed in our diets. The substitution is not infinite.
Yet, as I stood outside of the Explorado Market, a Fort Collins-local “Low Carb & Gluten-Free” store, specializing in products marketed towards ketogenic-practicing consumers, I couldn’t help but feel disarrayed. The ketogenic diet asks its practitioners to limit carbohydrates and increase fat intake (Mawer and Richter, 2020). As I watched consumers purchase “keto-friendly” products, containing sugar substitutes that claimed to offer “A zero-calorie natural sweetener that’s sweeter than sugar!” (Pure Sweet for Life, 2021), it was clear something was wrong. Instead of utilizing these low-calorie substitutes for therapeutic purposes, consumers thrust these alternatives into the long-term picture of their lives — leading to physiological and psychological issues.
Sugar substitutes, sometimes labeled as artificial sweeteners, are food additives that replicate sugar’s taste, usually with less food energy — often advertised as zero-calorie sweeteners (Tandel, 2011). There is a multitude of different types of sugar substitutes — falling within three categories: sugar alcohols, naturally plant-derived sugars, and synthetic, artificial sugars.
Erythritol, Sorbitol, and Xylitol are several sugar alcohols, commonly found in artificially sweetened gum, frozen desserts, and protein bars. Stevia, extracted from the Stevia rebaudiana plant, and Mogrosides, extracted from monk fruit (commonly recognized as Luo Han Guo) are the most popular natural sweeteners, appearing in restaurant sweetener packets, liquid sweetener drops, and granular baking additives. Aspartame, Saccharin, Sucralose, Acesulfame potassium, and Neotame, are all created artificially through chemical synthesis (Koeller and Wong, 2001). Aspartame, known as NutraSweet and Equal, commonly appears in low-calorie fruit drinks. Acesulfame potassium, known as “Ace K,” usually blends with aspartame in carbonated beverages to mask its bitter aftertaste — and sucralose is the world’s most commonly used artificial sweetener — you may know it as Splenda.
Confused? Don’t worry — most of society is. In all, there are over 40 alternatives, with each substitute containing a different chemical constitution and taste experience. These are not a “one-size-fits-all” product. Different sugar substitutes, justly, have different effects on our bodies — yet many organizations, such as the US Food and Drug Administration (FDA), largely combine studies on all of these compounds into an indistinguishable clump. Often ignored is the fact that many of the abnormal physical effects noticed with sugar substitutes were only found in epidemiological, in vitro, and animal trials (Higgins & Mattes, 2019), not in humans. Dr. Richard D. Mattes of Purdue University, an author of a 2019 study on low-calorie sweeteners’ effects on body weight, provides new insights from his research.
“I should be clear, that study was the very first of its time — we have to interpret this study very cautiously until somebody replicates it and proves the effect,” Dr. Mattes warned. “However, the interesting thing we found was that different low calories sweeteners have different effects. The reality is they’re all different chemicals, digesting differently — some are absorbed into the bloodstream and some area not, and some make it to the colon to influence microbiota, whereas others don’t.”
Dr. Mattes’ research is within the field of weight management and moderating energy intake — with a background in sensory science, spending 13 years at Monell Chemical Sense Center, a nonprofit research institute devoted to the study of taste and smell. All of this is to say that Dr. Mattes has an astute orientation toward sensory components and drivers in our food choice, which is uniquely applicable to the case of sugar substitutes.
The study Dr. Mattes speaks of was somewhat simple; matching beverages on palatability and sweetness with four sweeteners: aspartame, saccharin, sucralose, and stevia, with a base variable beverage using sucrose — actual sugar. The study looked for different responses with different sweeteners amongst participants; interestingly, the study found that saccharin led to a response similar to sucrose, causing individuals to gain weight, whereas sucralose caused individuals to experience weight loss. Meanwhile, those that consumed stevia and aspartame saw minimal changes.
So — are these sugar substitutes safe for consumption? According to the FDA, six of these substitutes are approved for use: aspartame, sucralose, neotame, Ace-K, advantame, and saccharin — with stevia and monk fruit falling under the GRAS (Generally Recognized as Safe) category, awaiting approval from the FDA. Meanwhile, all other sugar substitutes seen on the market are regulated as a food additive and must undergo a premarket review and FDA approval, whereas GRAS substances do not require this premarket approval (FDA, 2014).
“Every governmental agency across the world is charged with evaluating the safety of the food supply in their nation, and all have concluded that these compounds are safe at the doses that are recommended for use,” Dr. Mattes said. “Now, efficacy is another matter — if these sweeteners are just added to the diet and not substituted for another energy source, like sugar, then the likelihood of modifying blood sugar levels, weight management, or energy intake are low — whereas substituting for another source of energy could see beneficial results.”
Dr. Mattes and researchers akin to his studies have all addressed these sugar substitutes' issues in causing cancer, diabetes, or metabolic syndrome — and all have been uniformly rejected by toxicologists. To many individuals struggling to maintain their health and blood-sugar regulation, these sugar substitutes can be incredibly helpful; that is, of course, if used in non-restrictive, approved ways. “The analogy I like to use is ‘What causes traffic accidents — automobiles or drivers?’, Dr. Mattes said, half-grinning. “It’s how you drive the car, not the car itself; it’s not the sweetener itself, but how you use it, that determines its efficacy.”
The other side of this puzzle is the psychological component, and Ashlie Johnson, a doctoral candidate in the Applied Social and Health Psychology program at Colorado State University, is key in analyzing this issue. Her focus is within food behaviors — such as whether or not individuals restrict intake or listen to their bodies for hunger cues — and in anti-diet approaches to health. Johnson’s interests have helped her create and teach a Psychology of Eating course at CSU, as well as a passionate interest in purely psychological studies that affect our food choices — such as Stanford University’s Dr. Alia Crum’s 2011 study.
“I think that study is one of my favorite studies I’ve ever read — I love telling people: “It was the same milkshake all along!”, exclaimed Johnson. For context, Dr. Crum’s study offered participants a 380-calorie milkshake, with pretenses that they were either consuming a 620-calorie “indulgent” or 140-calorie “sensible” shake. Ghrelin, the “hunger hormone,” was measured before and after, fascinatingly depicting results of lower ghrelin levels associated with indulgent shake consumption, and minimal ghrelin response from the sensible shake consumption. This went on to prove that food consumption is inherently affected by the mindsets we have around the food we eat (Crum et al., 2011).
How does this connect with sugar substitutes? Imagine eating a slice of chocolate cake, made with eggs, butter, milk, flour, and real sugar, coated with a rich, delicious chocolate ganache. Sound good? It should — these are natural, nutrient-dense ingredients that our bodies are physiologically conditioned to digest. Now, imagine eating a Quest Bar, a common protein bar sweetened with sucralose and erythritol — maybe even in a chocolate cake flavor if you’re feeling extra indulgent. That Quest Bar is viewed as a smart, low-calorie snack — much like the “sensible” shake from Dr. Crum’s study. While the protein bar may contain fewer calories, allowing an indulgence in the chocolate cake may contribute to decreased cravings, longer satiation, and diminished ghrelin levels — whereas the Quest Bar may only cause us to eat a bigger caloric load than the cake itself.
Thus is the issue with sugar substitutes — when we knowingly restrict our intake and fill up on what we perceive to be “smart” choices, this restriction and dieting behavior can lead to weight gain, disordered eating, and binge-like episodes. It’s less of an issue with the sugar substitute itself, and more with the mindsets we have around them.
“I would say that most of the issues society holds around these sweeteners are confounded by dieting,” Johnson said. “Many people claim that these substitutes lead to weight gain, but the number one predictor of weight gain over a period of time is a weight loss diet.”
Johnson makes a great point — the overall efficacy of these substitutes on human health has often been linked to people trying to cut calories, trim their waste, and overall: diet. Restriction through dieting takes self-control, which Johnson outlines as a depletable resource — the more we do these tendencies over and over again, the less satisfied we become, leading to binges and disordered eating.
“In the context of medical benefits, folks who need a low sugar diet, or can benefit from a keto diet — which is a very, very small portion of people — yeah, I think sugar substitutes have a place,” Johnson said. “I also think that people have a right to food autonomy; if people want to consume these products in a way that doesn’t reinforce negative ideas about themselves, I think that it could be healthy.”
As nutrition experts and food psychologists like Dr. Mattes and Johnson have increasingly nullified physiological claims of health hazards with sugar substitutes, so too have they attempted to decriminalize societal perceptions of sugar. Apart from the fact that our bodies require carbohydrates and sugar to function, allowing occasional indulgences in sugar-dense foods is positive in establishing a healthy, non-restrictive mindset around food.
“We’re all the same species, but we have diets that vary dramatically in protein, fat, carbohydrates, and many other nutrients” explained Dr. Mattes. “There is no such thing as one optimal diet; humans are extraordinarily resilient and flexible in how they respond to food intake.”
Instead of searching for ‘optimal diets’ or to ‘nail your macros,’ — find what works for you. While commercially approved sugar substitutes are inherently safe for consumption, take a moment to reflect on if low-calorie sweeteners are right for your circumstances. Acknowledging cravings and allowing a few sweet treats here and there leads to a healthy body and mind — that way, you can have your cake, and eat it too.
Benjamin Randall is a journalism student, triathlete, and science communicator, studying at Colorado State University in Fort Collins. A podcaster, Fulbright Scholar, and Instagram influencer, Randall aims to combine all his passions into a niche career as an adventure-travel journalist. Read along to find stories of the known, unknown, and everything in between — and be sure to leave a clap and comment!
