Our bodies and brains run on a simple sugar called glucose, but that cane sugar sitting on your table is sucrose. Confusing, right? Table sugar is called sucrose because it is one molecule of glucose and one molecule of fructose chained together. Fructose is a “simple sugar” like glucose, meaning it is a simple one-molecule substance. The carbohydrates we eat are turned into simple units of glucose within our bodies. So, what happens to our bodies when we consume glucose directly versus when we consume sucrose? A new study finds that the difference between the two even affects our ability to feel full after eating.
The Hormones Behind Hunger and Fullness
Hunger and the lack of hunger (fullness or satiety) are tied to two hormones within the body which are secreted by fat cells. The hunger hormone which tells you to eat is called ghrelin, and the hormone which (hopefully) tells you to stop eating when the body has received enough is called leptin. Certain conditions can lead to a decreased awareness in some people where they don’t pick up on the leptin cues their bodies give to stop eating.
Ghrelin and leptin are always in a delicate dance with one another. For those who are actively trying to lose weight through reducing their caloric intake, leptin gradually reduces over time. This is the methodology behind having “cheat days”; just one meal heavy in carbohydrates can boost the leptin levels and help stave off hunger more efficiently than before.
While ghrelin and leptin are secreted by fat cells, another hormone produced inside the intestinal system in response to food also works to reduce appetite and help you stop eating: Glucagon-like Peptide 1. To learn more about how the body’s hormones are changed by the intake of different forms of sugar, Glucagon-like Peptide 1 was measured along with ghrelin levels after participants drank beverages containing either 75 g of glucose or fructose.
Studying Glucose vs. Fructose's Effects on the Hunger Hormones
In the group of sixty-nine adults studied, drinking a beverage containing sucrose lead to a lower production of hunger-regulating hormones. The intake of either sugar caused a fall in ghrelin levels as the body recognized the participants had gotten the signal to intake energy and responded by drinking the beverage. However, the science behind hunger and fullness showed that table sugar (sucrose) was less efficient in helping the body produce hormones to cause fullness.
In addition, there was a difference in how the different sugars were metabolized based on the body mass index (BMI) of the participants: obese participants who consumed table sugar had smaller blood sugar spikes than those at a normal BMI. Another interesting finding was that men who consumed table sugar had smaller increases in one of the hunger-regulating hormones (Glucagon-like Peptide 1) than the female participants.
The Real World Applications of the Study
Glucose isn’t a common additive in our foods, so it’s rare to find it on a nutrition label. Understanding that most of the substances listed on nutrition labels ending with -ose are forms of sugars that have varying numbers of molecules can help us recognize hidden sugars. Carbohydrates like bread, pasta, and rice are all converted straight into glucose within our bodies, while fruits and vegetables contain sucrose.
To sum it up, this study demonstrates that how the body processes the different types of sugars is dependent on whole-body factors, like body weight and gender, and helps us understand why drinking a tasty cappuccino loaded with sugar and flavoring syrup doesn’t help us feel as full as a carbohydrate-rich meal—even if the amount of carbs and sugars were identical.
Alexandra G Yunker, Shan Luo, Sabrina Jones, et al. Appetite-Regulating Hormones Are Reduced After Oral Sucrose vs Glucose: Influence of Obesity, Insulin Resistance, and Sex, The Journal of Clinical Endocrinology & Metabolism, , dgaa865, https://doi.org/10.1210/clinem/dgaa865