Sugar Rush or Sugar Crash? A Meta-Analysis of Carbohydrate Effects on Mood: Do not have a beneficial effect on any aspect of mood, lowers alertness within 60 minutes after consumption, increase fatigue within 30 min post-consumption

Sugar Rush or Sugar Crash? A Meta-Analysis of Carbohydrate Effects on Mood. Konstantinos Mantantzis, Friederike Schlaghecken, Sandra I.Sünram-Lea, Elizabeth A.Maylor. Neuroscience & Biobehavioral Reviews, Apr 3 2019. https://doi.org/10.1016/j.neubiorev.2019.03.016

Highlights
•    Carbohydrates do not have a beneficial effect on any aspect of mood.
•    Carbohydrate consumption lowers alertness within 60 minutes after consumption.
•    Carbohydrates increase fatigue within 30 minutes post-consumption.

Abstract: 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.