Food and Behaviour Research

Donate Log In

How Food Affects Your Brain: The Role of Nutrition and Diet in the Mental Health Crisis - BOOK HERE

Sugar Rush or Sugar Crash? A Meta-Analysis of Carbohydrate Effects on Mood

Mantantzis K, Schlaghecken F, S├╝nram-Lea SI, Maylor EA (2019) Neurosci Biobehav Rev.  101 45-67. doi: 10.1016/j.neubiorev.2019.03.016. Epub 2019 Apr 3. 

Web URL: Read this and related abstracts on PubMed here


The effect of carbohydrate (CHO) consumption on mood is much debated, with researchers reporting both mood improvements and decrements following CHO ingestion.

As global consumption of 
sugar-sweetened products has sharply increased in recent years, examining the validity of claims of an association between CHOs and mood is of high importance.

We conducted a systematic review and 
meta-analysis to evaluate the relationship between acute CHO ingestion and mood. We examined the time-course of CHO-mood interactions and considered the role of moderator variables potentially affecting the CHO-mood relationship.

Analysis of 176 effect sizes (31 studies, 1259 participants) revealed no positive effect of CHOs on any aspect of 
mood at any time-point following their consumption. However, CHO administration was associated with higher levels of fatigue and less alertness compared with placebo within the first hour post-ingestion.

These findings challenge the idea that CHOs can improve 
mood, and might be used to increase the public's awareness that the 'sugar rush' is a myth, inform health policies to decrease sugar consumption, and promote healthier alternatives.


Consumption of sugar and/or other carbohydrates fails to improve mood at any timepoint studied, according to this systematic review of all the available evidence from placebo-controlled trials.

Even within the first hour after consumption, the researchers found that ingestion of sugary or 'carb-rich' foods or drinks was linked with lower energy and alertness - not higher levels, as is widely assumed.

See the associated news article: