There are many negative effects sugar can have on the body.
Per Harvard Health Publishing, when we eat sugar, most of it gets broken down and absorbed in the small intestine. Specialized enzymes attack larger molecules and convert them into three simpler sugars: glucose, galactose, and fructose. The liver and muscles store some of the glucose as glycogen, a molecule that can be turned back into glucose when your body needs it.
When glucose enters the bloodstream, however, levels of blood glucose rise. In response, the pancreas secretes insulin to help glucose get where it needs to go in your body. If you’re consuming large amounts of added sugar, the cells can become resistant to insulin over time — a risk factor for systemic inflammation, type 2 diabetes, and other chronic conditions.
According to a study published in November 2016 in the journal Nutrients, consuming too much added sugar has also been linked to weight gain and obesity, risk factors for heart disease, nonalcoholic fatty liver disease, and cancer.
There are 12 signs your eating too much sugar
1. Increased Hunger and Weight Gain
If you’re consuming a lot of extra calories through added sugars, increased hunger is one of the first signs. “[Sugar] is satisfying to the taste buds, but it doesn’t really satisfy or fill our stomachs,” Keri Stoner-Davis, RDN, who works at Lemond Nutrition in Plano, Texas.
Without protein, fiber, and healthy fats, which most processed snacks and sugary treats lack, the body burns through sugar quickly and ramps up hunger, which can lead to mindless and even compulsive snacking, Cording says.
According to a review and meta-analysis, consumption of sugar-sweetened beverages promotes weight gain in adults and children.
Yet it’s not only the extra calories that can increase weight.
The gut microbiome, an ecosystem made up of 39 trillion microorganisms, is the body’s self-defense system, according to an article published in May 2016 in Cell. A healthy gut helps our metabolism regulate blood glucose and insulin levels and, in part, enables our bodies to use lipids and manage cholesterol. “When you have added sugar, it damages that ecosystem,” Dr. Li says.
Good bacteria decrease and bad bacteria overgrow, leading to dysbiosis (an imbalance between these bacteria) as well as problems with metabolism and the ability to properly process lipids and cholesterol.
What’s more, sugar may damage our fat hormones, including leptin, which inhibits hunger, Li argues. “High sugar disrupts metabolism, in part by interfering with leptin,” according to Li. “Eating sugar makes you want to eat more sugar, which makes you more hungry.”
If you’re feeling on edge , moody, irritable, stress may not be the only reason — it could be a sign that you’re eating too much sugar.
A high-sugar meal or snack without protein and fat quickly spikes your blood sugar, but as your body rushes to process all of it, your energy levels crash, making you feel sluggish and irritable, Cording says.
Also, when there’s low glucose in the bloodstream because your insulin levels have spiked after eating a lot of added sugar, levels of blood glucose in the brain decrease as well. “Our brains are absolutely critically dependent on having a normal level of blood sugar to fuel them,” Li says.
The important thing is to pay attention when you’re feeling off. For example, if you start to feel irritable an hour after you eat a snack or at the same time every day, excess sugar could be to blame. “If you notice that’s happening to you a lot, it’s a good opportunity to take a look at what you’re eating,” Cording says.
3.Fatigue and Low Energy
Sugar is easily digested and absorbed , so if you’re feeling fatigued, it could be due to the amount of sugar you’re getting in your diet.
“Sugar is a very quick energy source, so regardless of how much you eat, in 30 minutes you’re going to be hungry again, low on energy, or looking for energy again,” Stoner-Davis says.
Large swings of blood sugar and insulin can also cause energy levels to plummet and affect your overall energy level, Li says.
4. Foods Don’t Taste Sweet Enough
If you’ve noticed that foods don’t taste as sweet as they used to, or if you need to add sugar to foods to make them taste good (think: dusting your cereal with brown sugar), it could be that you’re getting too much sugar to begin with.
If you’re trying to make healthier choices, say by switching from flavored yogurt to plain yogurt, the difference will be more noticeable.
“You train your brain to expect a very high level of sweetness, and when you’re used to that, it can be harder to feel satisfied with foods that are less sweet because you’re primed to expect the high sweet levels,” Cording says.
If you’re replacing sugar with artificial sweeteners in your diet, you may also want to give it a second thought. “A lot of these sugar substitutes are so much sweeter than actual sugar so it tricks our brains into expecting this insanely high level of sweetness,” Cording says. This can increase sugar cravings overall.
5. Cravings for Sweets
If you’re craving sweets, you may be addicted to the feel-good effects that sugar has on your brain. Sugar targets the brain’s pleasure center (called the mesocorticolimbic pathway), triggering a rise in the so-called "happy hormone" dopamine, Cording says.
This pathway in the brain plays a significant role in the food choices we make, including affecting cravings for sugar.
Put simply, eating sugar increases dopamine, and the dopamine rise itself can increase cravings for sugar, leading to a vicious cycle, according to research.
The good news is that focusing on small meals and snacks comprised of real, whole foods, and eating regularly, can help those cravings improve, Stoner-Davis says.
6. High Blood Pressure
If you’ve been diagnosed with hypertension, too much added sugar in your diet could be a contributor.
Yet Li cautions that a direct cause-and-effect relationship hasn’t been found. However, what scientists do know is that high levels of glucose can damage the lining of our blood vessels, making it easier for lipids like cholesterol to stick to the walls of the blood vessels. “When that happens, you get hardening of the blood vessels. When your blood vessels get hardened, your blood pressure goes up,” Li says.
7. Acne and Wrinkles
If you’re battling acne, it may be worthwhile to consider how much added sugar you’re eating, suggests the American Academy of Dermatology Association. “Glycemic control plays a significant role in skin health and acne,” Cording says. For example, one study suggests that insulin resistance may influence the development of acne.
Wrinkles may be another sign that you’re consuming too much sugar. Advanced glycation end products, which are products of excess sugar, encourage skin aging, notes an article published in March 2020 in Nutrients.
8. Joint Pain
If you notice pain in your joints, it may not be age alone.
According to a survey published in December 2017 in the journal Arthritis Care & Research, among the 24 percent of respondents who had rheumatoid arthritis (RA) and said food affected their symptoms, soda and desserts were most commonly cited.
Consuming too much sugar can lead to systemic inflammation, which may lead to joint pain, Cording says. That said, there are several causes of joint pain, she adds, so improving your diet by cutting back on the sweet stuff may not be a magic bullet.
9. Sleep Issues
If you’re having trouble falling or staying asleep, you may want to take stock of what you’re eating.
According to a study of 300 university students published in August 2019 in the American Journal of Lifestyle Medicine, poor sleep quality is significantly related to higher consumptions of added sugars.
Our sleep cycles and the quality of sleep are regulated by the light and the temperature of the room, as well as glycemic control. “For someone who is chronically consuming excessive amounts of added sugar, it can absolutely mess with their sleep cycle and sleep quality,” Cording says.
10. Digestive Issues
If you’re having stomach pain, cramping, or diarrhea, there may be many causes to blame, and your doctor can help you get to the bottom of your symptoms. Too much sugar, a known gut irritant, is one of the possible culprits, Cording says.
Plus, for those with underlying health conditions such as irritable bowel syndrome, Crohn’s disease, or ulcerative colitis, or for those who have had stomach surgery, sugar can also exacerbate gastrointestinal symptoms, Stoner-Davis says.
If high-sugar foods are replacing fruits, vegetables, and whole grains, which offer fiber, constipation can be a problem, too.
11. Brain Fog
Problems with mental clarity, focus and concentration, and memory could be a result of consuming too many added sugars.
Although glucose is the brain’s primary source of fuel, excess amounts can cause hyperglycemia, or high blood glucose levels, and have an inflammatory effect in the brain and a negative impact on cognitive function and mood, Cording says.
According to research, impairments with information-processing speed, working memory, and attention were found in people with type 2 diabetes who had hyperglycemia.
Research suggests the same is true for those without diabetes. A study that found high blood glucose has a negative impact on cognition, including decreases in delayed recall, learning ability, and memory consolidation.
The bacteria in our mouths like to feed on simple sugars, so if your dentist is finding more cavities, or if you’ve been diagnosed with gum disease, it could be that you’re eating too much added sugar, Stoner-Davis says.
Although cutting back on added sugars is a good idea, if you’re going to consume a high-sugar food, swish water around your mouth afterward or eat it with foods like carrots or milk, which protect the teeth and provide a coating, Stoner-Davis says.