As mouth-watering as a sugar-laden sundae or icing-topped cupcake is, we should all know by now that sugar isn’t exactly healthy. In fact, it may be one of the worst things you can eat (that is, if you’re trying to live a long, healthy life).
One study from UC San Francisco actually found that drinking sugary drinks like soda can age your body on a cellular level as quickly as cigarettes. The way the sweet stuff impacts your body is way more complex than just causing weight gain. In fact, when you eat a ton of sugar, almost every part of your body feels the strain—and that’s bad news for your health in both the short term and especially the long term.
From an initial insulin spike to upping your chances of kidney failure down the road, this is what really happens in your body when you load up on sugar.
Your brain responds to sugar the same way it would to cocaine.
Eating sugar creates a surge of feel-good brain chemicals dopamine and serotonin. So does using certain drugs, like cocaine. And just like a drug, your body craves more after the initial high. “You then become addicted to that feeling, so every time you eat it you want to eat more,” explains Gina Sam, M.D., M.P.H., director of the Gastrointestinal Motility Center at The Mount Sinai Hospital.
Your insulin spikes to regulate your blood sugar.
“Once you eat glucose, your body releases insulin, a hormone from your pancreas,” Dr. Sam explains. The insulin’s job is to absorb the excess glucose in the blood and stabilize sugar levels.
And a little while later you get that familiar sugar crash.
Once the insulin does its job, your blood sugar drops again. Which means you’ve just experienced a sugar rush, and then a drastic drop, leaving you feeling drained. “That’s the feeling you get when you’ve gone to the buffet and you’ve overdone it, and all you can do is lie on the couch,” explains Kristen F. Gradney, R.D., Director of Nutrition and Metabolic Services Our Lady of the Lake Regional Medical Center, and spokesperson for the Academy of Nutrition and Dietetics.
In fact, eating too much sugar can make you feel tired. All. The. Time.
Feeling sluggish all the time, or always being hungry or thirsty can all be signs you’ve been binging on a little too much sugar. “Your body’s physiologic response is to send out enough insulin to deal with all the sugar and that can have a sluggish effect,” Gradney explains. “Additionally, if you are only eating simple sugars, you will feel hungry and tired because you are not getting enough of the other nutrients to sustain your energy,” like protein and fiber.
You may start to notice you’re putting on some extra weight.
The equation is pretty simple: Excess sugar equals excess calories equals excess weight in the form of fat. Not only do high sugar foods pack a ton of calories into a small amount, but they contain almost no fiber or protein—so you often end up eating much more before you feel full. Dangerous cycle. “If you’re just eating sugar, you may be gaining weight but still feeling hungry,” Gradney says. She adds that you could easily gain a pound over the course of a week from eating one candy bar and one 20-ounce soda (that’s 500 extra calories) each day.
Long term, eating too much sugar can lead to obesity.
Our high-sugar diets are a big part of why more than one-third of American adults are clinically obese.
And obesity can lead to insulin resistance, which ramps up blood sugar levels, which leads to diabetes.
When you’re overweight or obese, your cells can become resistant to the normal effects of insulin (for reasons that aren’t 100 percent understood), and struggle to absorb glucose from the blood to use for energy. So your pancreas goes into overdrive to produce more insulin. But despite the excess insulin trying to do its job, the cells still do not respond and accept the glucose—which ends in excess sugar floating around in your bloodstream, with nowhere else to go. Above-normal blood glucose levels is called prediabetes. When blood sugar levels reach even higher, that’s type 2 diabetes.
Your liver plays an important role in metabolizing carbohydrates by taking excess glucose out of the blood stream and storing it for later use.
One of the liver’s functions is regulating blood sugar levels. Your cells use the glucose in your blood for energy, and your liver takes the excess and stores it in the form of glycogen. When your cells need energy later, like in between meals, the liver will release glucose back into the bloodstream.
But your liver can only store a certain amount of glucose, so the rest can accumulate as fat in the organ.
“If you exceed this amount, it turns into fatty acids and that’s when you get fat deposits in the liver,” Sam explains. That can lead to nonalcoholic fatty liver disease, a condition when your body contains more fat than it can metabolize, causing it to accumulate in the liver cells. (Sugar isn’t the sole cause, but glycogen storage is a big contributor, as is any sugar-induced weight gain.) “Fatty liver can develop within a five-year period,” Gradney explains. But it can happen even quicker based on your dietary habits and genetic predisposition to insulin resistance. If it progresses, it can eventually lead to liver failure down the road. Your love of soda isn’t really worth that, is it?
Having blood saturated with sugar can damage pretty much every other organ, too, as well as your arteries.
Trying to pump blood full of sugar through blood vessels is basically like pumping sludge through a teeny tiny pipe. “The pipes will finally get tired. That’s what happens with your vessels,” Gradney explains. So any area relying on small blood vessels can become affected—kidneys, brain, eyes, heart. “It can lead to chronic kidney disease or kidney failure, high blood pressure, and you have an increased risk of stroke if you have high blood pressure.”
It also screws up your skin by breaking down collagen and aging you faster.
In addition to slathering on fancy anti-aging serums and SPF, cutting back on sugar can help skin look younger for longer. “The collagen and elastin fibers in the skin are affected by a lot of sugar in the bloodstream,” explains dermatologist Debra Jaliman, M.D. Through a process called glycation, glucose attaches to proteins in the body. This includes collagen and elastin, the proteins found in connective tissues that are responsible for keeping skin smooth and taught. Studies have shown glycation makes it harder for these proteins to repair themselves, resulting in wrinkles and other signs of aging.
As your dentist has probably told you, eating a lot of sugar leads to tooth decay.
“The sugar itself doesn’t do any damage, but it sets off a chain of events that can,” explains Jessica Emery, D.M.D., owner of Sugar Fix Dental Loft in Chicago. “We have bacteria in our mouths that feed on the sugars that we eat; when this takes place it creates acids that can destroy tooth enamel. Once the tooth enamel is weakened, you’re more susceptible to tooth decay.”
If you’re ready to eat less sugar, simply reading nutrition labels is a good way to start. But the basic fact is there’s no “right” amount of sugar you should be consuming.
Added sugar is packed into so many foods that you’d never really think about (case and point: ketchup). “We encourage people to read labels and count grams of sugar,” Gradney says. According to the Academy, there’s no hard and fast recommendation for daily intake, she adds. Good rule of thumb: “Always choose the option that has the least amount of sugar in it. If you have juice or soda, choose water.” Choose whole fruits instead of drinking the juice—the sugar content is less concentrated and the fiber helps your body break it down more effectively. And choose whole foods to naturally limit the amount of sugar in your meals. “The more you stay away from processed foods, the better off you’ll be.”