How Much Is Too Much?

The growing concern over too much added sugar in our diets

For most people, experts agree that some added sugar in the diet is fine. But the truth is, most Americans are consuming way too much — on average, nearly 57 pounds of added sugar per person, every year. This could be affecting us in ways that make us prone to craving more sugar and to obesity.

How much is okay?

Expert panels worldwide have made consistent recommendations on daily sugar intake. The American Heart Association (AHA) recommends no more than 6 teaspoons (25 grams) of added sugar per day for women and 9 teaspoons (38 grams) for men.1 The AHA limits for children vary depending on their age and caloric needs, but range between 3-6 teaspoons (12 - 25 grams) per day.

That is in line with the World Health Organization's (WHO) recommendation that no more than 10% of an adult's calories – and ideally less than 5% – should come from added sugar or from natural sugars in honey, syrups and fruit juice. For a 2,000-calorie diet, 5% would be 25 grams.

Limit daily sugar to 6 tsps (25 g) for women, 9 tsps (38 g) for men.

Yet, the average American consumes 17 teaspoons (71.14 grams) every day.2 That translates into about 57 pounds of added sugar consumed each year, per person.3

Children and teens are particularly at risk. The U.S. Dietary Guidelines for Americans recommend limiting total intake of discretionary calories, including both added sugars and fats, to 5% –15% per day. Yet children and adolescents in America obtain about 16% of their total caloric intake from added sugars alone.4

Sugar leaves us craving more

It's easy to exceed those limits. With as many as 11 teaspoons (46.2 grams) of added sugar in one 12 oz. soda, a single serving is close to double most people's daily sugar allowance.5 But sugar also is pervasive in our food supply. A leading brand of yogurt, for example, has 7 teaspoons (29 grams) of total sugars in a single serving, most of it added.

The sugar in one 12-oz soda is as much as in 1 orange + 16 strawberries + 2 plums.

Research also shows that, for some people, eating sugar produces characteristics of craving and withdrawal, along with chemical changes in the brain's reward center, the limbic region.

Using brain-scanning technology, scientists at the U.S. National Institute on Drug Abuse were among the first to show that sugar causes changes in peoples' brains similar to those in people addicted to drugs such as cocaine and alcohol.6,7 These changes are linked to a heightened craving for more sugar.8 This important evidence has set off a flood of research on the potentially addictive properties of sugar.9

Natural changes lead to weight gain

Consuming too much added sugar over long periods of time also can affect the natural balance of hormones that drive critical functions in the body. Eating sugar increases levels of glucose in the bloodstream, which leads the pancreas to release insulin. Higher levels of insulin, in turn, cause the body to store more food calories as fat.

Insulin also affects a hormone called leptin, which is our natural appetite suppressant that tells our brains we are full and can stop eating. Imbalanced insulin levels, along with high consumption of certain sugars, such as fructose, has been linked to a condition called leptin resistance,10 in which the brain no longer "hears" the message to stop eating, thus promoting weight gain and obesity.

Leptin resistance enabled our ancestors to survive long periods of limited food supply by encouraging them to overeat during times of plenty and enabling them to conserve more calories as fat. In the modern world, that's not a benefit. To make matters worse, people with leptin resistance also tend to feel sluggish, making it difficult to be active and contributing to further weight gain.

[1] Johnson, R.K., Appel, L., Brands, M., Howard, B., Lefevre, M., Lustig, R., Sacks, F., Steffen, L., & Wyllie-Rosett, J. Dietary sugars intake and cardiovascular health: a scientific statement from the American Heart Association. Circulation , 120(11), 1011-20. doi:10.1161/CIRCULATIONAHA.109.192627. Retrieved from http://circ.ahajournals.org/content/120/11/1011.full.pdf

[2] 2015-2020 Dietary Guidelines for Americans Cut Down on Added Sugars. Retrieved from https://health.gov/dietaryguidelines/2015/resources/DGA_Cut-Down-On-Added-Sugars.pdf

[3] United States Department of Agriculture, Economic Research Service. USDA Sugar Supply: Tables 51-53: US Consumption of Caloric Sweeteners. Retrieved from http://www.ers.usda.gov/data-products/sugar-and-sweeteners-yearbook-tables.aspx

[4] Ervin, R.B., Kit, B.K., Carroll, M.D., & Ogden, C.L. U.S. Department of Health and Human Services, Centers for Disease Control and Prevention. NCHS Data Brief No. 87: Consumption of added sugar among U.S. children and adolescents, 2005â€“2008. . Retrieved from http://www.cdc.gov/nchs/data/databriefs/db87.htm

[5] Soft drinks: sugar content. Retrieved from http://www.floridahealth.gov/chdcollier/Documents/ToothFairy/sugarinsodas.pdf

[6] Volkow, N.D., & Li, T.-K. Drug addiction: the neurobiology of behaviour gone awry. Nature Reviews Neuroscience , 5(12), 963-970.

[7] Brownell, K.D., & Gold, M.S. Food and addiction: A comprehensive handbook. () Oxford University Press.

[8] Avena, N., Rada, P., & Hoebel, B. Evidence for sugar addiction: behaviroal and neurochemical effects of intermittent, excessive sugar intake. Neuroscience Behavior Review , 52(1), 20-39. Retrieved from http://www.ncbi.nlm.nih.gov/pubmed/17617461

[9] Garber, A.K., & Lustig, R.H. Is fast food addictive?. Current Drug Abuse Reviews , 4(3), 146-162.

[10] Shapiro, A., Mu, W., Roncal, C., Cheng, K.-Y., Johnson, R.J., & Scarpace, P.J. Fructose-induced leptin resistance exacerbates weight gain in response to subsequent high-fat feeding. American Journal of Physiology. Regulatory, Integrative and Comparative Physiology , 295(5), R1370â€“1375. doi:10.1152/ajpregu.00195.2008