Diet and disabilities—2
Are we chasing a sugar high again?
In a press conference 22 April 2025, Robert F. Kennedy, Jr., US Secretary of Health and Human Services, while announcing that the US Food and Drug Administration will promote removal of synthetic dyes from foods (see press release), also expressed concern about sugar in children’s diets. He said, “sugar is poison.”
Secretary Kennedy’s comments, which included his observations about childhood diabetes, were covered widely in US news sources (see, for example, Sheryl Gay Stolberg’s and Kim Severson’s coverage for the New York Times and Fox17 Nashville’s YouTube video).
I have written about some topics in the diet-disability space previously, particularly in an earlier post in this series (Diet and Disabilities—1), and I’ll return to them in this and a subsequent post or two. This one is about sugar’s effects on behavior. Before I turn to sugar in our food for this post, let me remind regular readers of Special Education Today that some posts go behind a paywall a week or so after they are published; paid subscribers have access to all the earlier posts in SET dating back to 2021.
Here I have reprinted the bulk of my report from 1994.1
Sugar High?
Information and Links about Effects of Sugar on Children's Behavior
Sugar apparently is not as bad for children as popularly believed. A study reported in the New England Journal of Medicine concludes that contrary to the belief of many parents... sugar does not turn their children into hyperactive terrors. In fact... the researchers say their study suggests that sugar may even have a slight calming effect.
The researchers say that despite their findings... they expect many parents will continue to believe sugar causes bad behavior in children. They suggest that parents who are concerned about hyperactive children should not just blame sugar... but should take them to a doctor for an examination.
After hearing a story on National Public Radio, I clipped these two paragraphs from the UPI newswire (3 Feb 1994). I also looked at the study itself. It was conducted by Mark Wolraich and colleagues and included a double-blind design in which lots of families participated. The families' diets were closely controlled (e.g., food stuffs removed from house, meals prepared by the research project). Over many weeks, families ate foods that were sometimes sweetened by sugar and sometimes sweetened by two artificial agents; they got these special diets in different orders. Differences in the sweeteners did not affect children's activity level or several other measures.
Though these results probably do not surprise many of us, I thought the UPI story had it right: "many...will continue to believe sugar causes bad behavior." How come common wisdom indicates a connection when careful research doesn't? Perhaps it's because our informal observations miss some other critical factors. Here are alternative explanations for the appearance of a connection between consumption of sugar and hyperactive behavior:
Some other agent in the foods consumed by children may increase their activity level. For example, perhaps the caffeine in chocolate is the active ingredient. This surely can be tested empirically.
Some other environmental condition may be responsible for more "hyper behavior." For example, it is usually right after dessert that all the cousins get to leave the constrained situation at the dinner table and play; it's not the dessert but the change to a situation where racing about and talking animatedly is O.K.
In any case, there's pretty good scientific consensus that sugar consumption does not cause hyperactivity. Perhaps, in some extraordinarily rare cases, sugar may cause problems, but those cases wouldn't be reason to make general statements about causation
So that was what I wrote in the 1990s (and updated in the 2000-2010s. Are those conclusions out of date?
More recent research reports
I spent a few hours searching for more recent studies that examined the connection between sugar and behavior (especially hyperactivity and attention deficit disorder). I didn’t conduct an integrative literature review of the sort that I used to teach in class for graduate students (they called it “the meta class”). This is just a selection of studies that I found while reading reports from the years between 2020 and 2025.
Beecher (2021) reported that adolescents who consumed excessive amounts of sugar had ADHD symptoms and cognitive problems as adults.
de Oliveira Rios and Klettenberg (2024) analyzed 12 articles and, “Although there is no proven link between sugar consumption in the diet and symptoms, excessive sugar consumption may be one of several potentially relevant factors,” they called for more research.
Ditasari and Putri (2024) reported an uncontrolled case.
Khazdouz and colleagues (2023), who examined nine correlational studies about consumption of “junk food” (sweetened beverages, sweets, candies) by children and ADHD symptoms, reported a positive relationship between the two.
Kim et al. (2024) assessed the daily consumption of sugar-sweetened beverages by > 330,000 children at ~ age 2 years. The followed those children for an average of 9 years and found that the toddlers with higher consumption of sugary beverages (as reported in parental interviews) had a higher risk of meeting criteria for ADHD after age 6.
Some studies appear to examine questions that don’t go to the center of the issue of the sugar ➔ hyperactivity. For example, one examined whether heavy consumption of sugary drinks increased ADHD symptoms among medical students.
Please do not consider this list of findings to be a thorough or comprehensive “review.” However, please do note that the results reported in these studies do not provide a conclusive indication that sugar causes hyperactivity or behavior problems. Indeed, the author teams that reported positive relationship often were careful not to assert a causal connection. In many of the reports that argued for a connection between sugar and behavior, weasel words are common.
At best, I think we can say that a causal relationship between sugar and its relatives and hyperactive behavior remains to be demonstrated. If there is a causal relationship, it is logically not proven and probably exists primarily in our fallible human perception of connections.
This is not to say that it is probably a good idea to reduce consumption of refined sugar because it has other deleterious heath consequences (e.g., obesity, diabetes). Also, one would have a difficult time eating a healthy diet without consuming sugars, as they occur naturally in many food (fruits, vegetables) that should be a part of healthy diet. But, I think arguing that we should reduce sugar intake because it causes behavior problems is unfounded.
References
Beecher, K., Alvarez Cooper, I., Wang, J., Walters, S. B., Chehrehasa, F., Bartlett, S. E., & Belmer, A. (2021). Long-term overconsumption of sugar starting at adolescence produces persistent hyperactivity and neurocognitive deficits in adulthood. Frontiers in Neuroscience, 15, 670430.
de Oliveira Rios, R., & Klettenberg, M. R. P. (2024). Effect of sugar on ADHD symptoms in children up to 12 years old. Revista Eletrônica Acervo Saúde, 24(9), e17310-e17310.
Ditasari, N. N., & Putri, D. A. (2024). The impact of reducing consumption of sugar-sweetened beverages (SSB) on the behavior of children with attention deficit hyperactivity disorder (ADHD). Psikoscientia, 1(1).
Khazdouz, M., Safarzadeh, R., Hejrani, B., Hasani, M., Mahdavi, F. S., Ejtahed, H. S., & Qorbani, M. (2024). The association between junk foods consumption and attention deficit hyperactivity disorder in children and adolescents: a systematic review and meta-analysis of observational studies. European Child & Adolescent Psychiatry, 1-10.
Kim, S., Shin, J., Cha, H. R., Ha, E. K., Kim, J. H., & Han, M. Y. (2024). Consumption of sugar-sweetened beverages before 2 years of age and attention-deficit/hyperactivity disorder. Annals of Nutrition and Metabolism, 80(5), 276-286. https://doi.org/10.1159/00053948
Wolraich, M. L., Lindgren, S. D., Stumbo, P. J, Stegink, L. D., Applebaum, M. I., & Kiritsy, M. C. (1994). Effects of diets high in sucrose or Aspartame on the behavior and cognitive performance of children. New England Journal of Medicine, 330(5), 301-307.
Yingchankul, N., Panuspanudechdamrong, C., Techapipatchai, N., Chanmuang, T., Netsiri, P., Karawekpanyawong, N., ... & Phinyo, P. (2023). Is the Consumption of Added Sugar from Common Beverages Associated with the Presence of Attention Deficit Hyperactivity Disorder Symptoms in Thai Medical Students?. Nutrients, 15(20), 4395.
Footnote
I only reprinted the text; I did not include approximately 50 links from that report, as I doubt most of them would resolve; they would be “dead links.” Interested readers are welcome to read the archived original and test the links.