The Effects of Too Much Added Sugar

Consuming too much added sugar is detrimental to our health—here’s why, and what you can do about it.

Fifty-six. That’s how many different names the food industry uses for sugar.

Here’s another number: 19½. That’s, on average, how many teaspoons of added sugar each person in the U.S. consumes each day. To be clear: We’re talking about added sugar—the sugar the food industry adds to foods, not the sugar found naturally in foods. The daily maximum recommendation from the American Heart Association? Six teaspoons for women, 9 teaspoons for men, less than 6 teaspoons for children ages 2-18, and zero for children ages 2 and younger.

Ready for another? One-quarter: the number of pounds of added sugar Americans are consuming daily, on average, which equates to 90-100 pounds of added sugar annually. “The problem is you’re really supposed to be consuming zero [added sugar], but you could consume an ounce or an ounce and a half,” says Robert Lustig, M.D., a pediatric endocrinologist, professor of pediatrics in the Division of Endocrinology at University of California, San Francisco, and author of Fat Chance: Beating the Odds Against Sugar, Processed Food, Obesity, and Disease.

So, why is it a big deal that we’re consuming so much added sugar? Dr. Lustig—who was also featured prominently in the 2015 documentary Sugar Coated (available on Netflix) and is a member of the SugarScience team, an authoritative source for the scientific evidence about sugar and its impact on health—shares what we need to know and think about before saying “Yes” to sugary foods.

Glucose vs. Fructose

There are two main sugars found in foods, and it’s important to know the difference because one is necessary and one isn’t.

Glucose, which is found in starch, is the energy of life, according to Dr. Lustig. “Glucose is so important that if you don’t consume it, your body makes it,” he says. The liver has a way of turning fat into glucose called gluconeogenesis. So while it’s necessary for life, it’s not necessary to eat.

Fructose, on the other hand, is an entirely different molecule. “There’s no animal cell on the planet that needs fructose for any reaction at all,” Dr. Lustig explains, adding that it’s sweet, it’s energy, and it’s calories, but it’s not nutrition.

Effects of Too Much Sugar

Acutely, too much sugar doesn’t have significant effects on the body. It’s the long-term effects that are the issue.

Dr. Lustig says there are three things fructose does to our bodies that glucose does not:

Liver fat: “Because of the way fructose is processed, it goes to the liver and excess gets turned into liver fat, and that liver fat gums up the workings of the liver. When that happens, you end up with a phenomenon called insulin resistance. You have a situation where the liver’s not responding to the insulin signal so the pancreas has to make extra,” Dr. Lustig says, which raises insulin levels all over the body and leads to hyperinsulinemia.

Excess insulin, Dr. Lustig explains, does two things in your body to make you gain weight: It turns energy into fat cells, and it blocks leptin, the hormone that sends a signal to the brain when you’ve had enough to eat. Continued insulin secretion is also one of the major factors involved in chronic metabolic diseases, such as cardiovascular disease, Type 2 diabetes, cancer, and dementia. “All of those are referred to in total as metabolic syndrome. Some people will get some of those diseases, some people will get others of those diseases, and some unfortunate people will get all of them,” Dr. Lustig says. “Anything that drives insulin is going to drive those, and because of the liver fat issue, fructose drives it.”

Aging: Have you ever thought of why bananas brown? It’s a chemical reaction called the Millard reaction—the aging reaction. “All carbohydrates bind to proteins, all carbohydrates cause a mild reaction. But because of fructose’s unique chemistry, it causes that mild reaction to occur seven times faster and generate a hundred times the number of oxygen radicals called oxidative stress that damage proteins and lipids inside cells,” Dr. Lustig says. “So basically sugar drives aging faster than other carbohydrates.”

Dopamine: Fructose causes the reward system to release dopamine, the reward response. When dopamine is released, it fosters continued consumption, according to Dr. Lustig. “That’s something only fructose does. So you get into a vicious cycle of consumption and disease.”

To paint a clearer picture, Dr. Lustig compares fructose to alcohol: “Alcohol is calories, but it’s not nutrition. Consumption of alcohol is dangerous in two ways: It’s dangerous acutely, and it’s dangerous chronically. Fructose is not dangerous acutely, but it is dangerous chronically for the same reason that alcohol is. In fact, fructose and alcohol are metabolized exactly the same in the liver, and that’s why kids are getting the disease of alcohol—Type 2 diabetes and fatty liver disease—without alcohol. Fructose sugar is the alcohol of the child. While we have the capacity to metabolize a limited amount of alcohol, excess is dangerous. While we have a limited capacity to metabolize the sugar in our diet, excess is dangerous.”

What Happens When You Cut Sugar From Your Diet?

When sugar is cut from your diet, “your metabolic primers get better, and you feel better, and your metabolic parameters improve, and you detox, and you don’t crave it as much. Everything gets better,” Dr. Lustig says, referring to a study his team published in October 2015.

For that study, the research team studied the diets of 33 Latino and African-American kids with metabolic syndrome (obesity plus at least one other chronic medical condition) to determine a home-baseline diet. Then, for the next 10 days, sugar was cut from the kids’ diets. “What we did was we gave them starch instead so they would not loose weight. We took pastries out, and we put the bagels in. … We took the chicken teriyaki out, and we put turkey hotdogs in. We gave them processed foods, but there were no added-sugar foods,” Dr. Lustig explains.

After those 10 days, the kids were assessed, and “every aspect of their metabolic health improved and their liver fat reversed. That is without any change in calories or any change in weight. This shows fructose is the primary driver because when we gave them extra glucose instead of fructose, it got better unrelated to calories and unrelated to weight,” Dr. Lustig says. “That proves that sugar is the driver of these metabolic diseases. It may not be the only driver, but it certainly is the primary driver, and the one that children are exposed to.”

Easy Tips for Cutting Sugar

When working the following tips into your family’s lifestyle, the first thing to keep in mind is to cut back gradually and make realistic goals for your family. “It’s really hard to go to an extreme. I work with families that want to cut everything all at once, and that’s usually unsuccessful,” says Nicole Silber, R.D., a pediatric nutritionist based in New York City. “Meet your child where they’re at, engage them in the plan, and cut back slowly, which I think will end up yielding more success than to cut back drastically.”

Be weary of foods labeled as fat-free. “There are a bunch of fat-free items that tend to be loaded with sugar to compensate for the loss of fat in the product, especially in baked goods,” Silber says.

Opt for fresh fruit over dried fruit or fruit sauce. With dehydrated fruit and sauces, it’s a matter of the source of sugar being concentrated, Silber says. For example, when you dehydrate a plum, what’s left is the fiber and natural fruit sugar. “It ends up being much smaller, so you could eat five prunes, which will fill your stomach the same amount as one plum, but you’re consuming five times the amount of sugar because you’re essentially eating five plums,” Silber explains. The same thing happens with applesauce. “It will take a child a few minutes to eat a whole apple, which has the skin, the fiber, the liquid. When you boil it down and puree it into a sauce, you can probably have four or five apples in the same amount of time it would take to eat one whole apple,” Silber adds.

Choose plain yogurt over flavored. Yogurt can be unhealthy if you’re not picking the right one, Silber says. “If a child is used to high-sugar yogurts, you can add in your own fruit, jam, maple syrup, honey,” she advises. “You can even add in your own white sugar. I’m confident you will add in less than the food companies.” And make sure you check the labels on baby yogurts; Silber says some brands are really high in added sugar.

Preventatively, don’t introduce infants to juice or sweetened foods in their first year. Silber advises to give babies more veggies and less fruit to accustom their taste buds to less sweet foods. When shopping for baby foods or making your own, opt for blends that have one or no fruit.

Cut down your weekly dessert intake. Wherever your family is now, cut back one to two servings per week, Silber advises. “If a family has dessert every night, I would say cut back to five nights per week,” Silber says. Another option is to substitute fresh fruit and eat the fruit when it’s extra ripe because it will taste sweeter.

Drink water rather than sweetened beverages. Nearly two-thirds of kids in the U.S., ages 2-19, consumed at least one sugar-sweetened beverage per day, and roughly 30 percent of children consumed two or more, between 2011-2014, according to a study published in January by the Centers for Disease Control and Prevention’s National Center for Health Statistics. That includes soda, fruit drinks, sports and energy drinks, and sweetened coffees and teas.

Silber says most kids don’t need to consume beverages aimed toward athletes. “Usually water and a nutritious snack before and after will be sufficient to restore the nutrition and hydration,” she says.

Leave sugar out of recipes when possible. With cooking, Silber suggests cutting the sugar from the recipe entirely, or cutting it in half. “I do this a lot where I see a recipe for a marinade that has a lot of honey or white sugar that I will eliminate and I still think the recipe comes out tasty,” she says.

For baking, Silber says to look for recipes that use more natural forms of sugar, such as honey, agave, or maple syrup because they’re more concentrated, so you’ll use less of it. And remember: “There is a time and a place for [sweets],” Silber says. “Just because it doesn’t have the white sugar doesn’t mean it’s a food that should be given all the time.”

Read and understand the Nutrition Facts labels on packaged foods. The Food and Drug Administration announced a new Nutrition Facts label in May 2016, which among other changes includes an “Includes X g Added Sugars” field. Food manufacturers will need to implement the new label by July 26, 2018, while smaller companies will have an additional year to comply, according to the FDA.

Until then, Silber suggests thinking about it in terms of a sugar packet, which is approximately 4 grams of sugar. If you choose a food product that has 8-12 grams of sugar per serving, “envision yourself opening up two or three sugar packets and pouring that into your dish. That can become quite alarming,” she says.

Silber recommends choosing condiments (ketchup, salad dressing, and marinades) with less than 5 grams of sugar per serving, and foods (breads, yogurts, cereals, etc.) with no more than 10 grams of sugar per serving.

An easy way to keep track of your added sugar intake is to convert the grams per serving into teaspoons. There are 4.2 grams of sugar per teaspoon, Dr. Lustig says. That comes out to less than 25 grams per day for children and teens, 25.2 grams for women, and 37.8 grams for men. “We’re currently at about 90 [grams per day] on average. That’s a big difference,” Dr. Lustig says.

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