The effects of a 6-week controlled, hypocaloric ketogenic diet, with and without exogenous ketone salts, on cognitive performance and mood states in overweight and obese adults

Abstract

BackgroundKetogenic diets are a commonly used weight loss method, but little is known how variations in sodium content and ketones influence cognition and mood during the early keto-adaptation period.ObjectivesTo investigate the effects of an exogenous ketone salt (KS) as part of a hypocaloric KD on mood and cognitive outcomes in overweight and obese adults. A secondary objective was to evaluate changes in biochemical markers associated with inflammatory and cognitive responses.Materials and methodsAdults who were overweight or obese participated in a 6-week controlled-feeding intervention comparing hypocaloric diets (∼75% of energy expenditure). KD groups received twice daily ketone salt (KD + KS; n = 12) or a flavor-matched placebo, free of minerals (KD + PL; n = 13). A separate group of age and BMI matched adults were later assigned to an isoenergetic low-fat diet (LFD; n = 12) as comparison to KD. Mood was assessed by shortened Profile of Mood States and Visual Analog Mood Scale surveys. Cognitive function was determined by the Automated Neuropsychological Assessment Metrics mental test battery.ResultsBoth KD groups achieved nutritional ketosis. Fasting serum glucose decreased in both KD groups, whereas glucose was unaffected in the LFD. Insulin decreased at week 2 and remained lower in all groups. At week 2, depression scores in the KD + PL group were higher compared to KD + KS. Performance in the math processing and go/no-go cognitive tests were lower for KD + PL and LFD participants, respectively, compared to KD + KS. Serum leptin levels decreased for all groups throughout the study but were higher for KD + KS group at week 6. Serum TNF-α steadily increased for LFD participants, reaching significance at week 6.ConclusionDuring a short-term hypocaloric diet, no indication of a consistent decline in mood or cognitive function were seen in participants following either KD, despite KD + PL being relatively low in sodium. WK2 scores of “anger” and “depression” were higher in the LFD and KD + PL groups, suggesting that KS may attenuate negative mood parameters during the early intervention stages.

The Relationship of Ketogenic Diet with Neurodegenerative and Psychiatric Diseases: A Scoping Review from Basic Research to Clinical Practice

“…In a 6 week controlled-KD intervention, no evidence of a constant decrease in mood or cognition performance was found in adults affected by overweight or obesity ( n = 13) aged between 21 and 65 years [ 62 ]. The insertion of a ketone salt into a well-formulated hypocaloric KD attenuated negative mood parameters during the early intervention stages with no evidential variations in cognitive function [ 62 ].…”

“…In a 6 week controlled-KD intervention, no evidence of a constant decrease in mood or cognition performance was found in adults affected by overweight or obesity ( n = 13) aged between 21 and 65 years [ 62 ]. The insertion of a ketone salt into a well-formulated hypocaloric KD attenuated negative mood parameters during the early intervention stages with no evidential variations in cognitive function [ 62 ]. A significant advantage of this survey was the presence of a controlled-nourishing design, which guarantees that participating individuals efficiently adopt the applied nutritional intervention [ 62 ].…”

“…The insertion of a ketone salt into a well-formulated hypocaloric KD attenuated negative mood parameters during the early intervention stages with no evidential variations in cognitive function [ 62 ]. A significant advantage of this survey was the presence of a controlled-nourishing design, which guarantees that participating individuals efficiently adopt the applied nutritional intervention [ 62 ]. On the other hand, this survey was performed on a military sample group, and its findings cannot be extrapolated to the general population [ 62 ].…”

“…A significant advantage of this survey was the presence of a controlled-nourishing design, which guarantees that participating individuals efficiently adopt the applied nutritional intervention [ 62 ]. On the other hand, this survey was performed on a military sample group, and its findings cannot be extrapolated to the general population [ 62 ]. In a small clinical survey of 20 older adults with subjective memory complaints ( n = 11) or MCI ( n = 9), two diets were followed, including a modified KD [ 63 ].…”

Effects of Dietary Supplementation of a Microalgae Extract Containing Fucoxanthin Combined with Guarana on Cognitive Function and Gaming Performance

“…Cardona and coworkers [55] reported that eight weeks of multi-probiotic supplementation reduced errors of omission in Go trials (indicating an improvement in attention), with no impact on memory in patients with fibromyalgia. Moreover, Kackley and associates [56] reported that ingesting ketogenic salts may attenuate negative aspects of mood associated with diet intervention. Our group has also reported that acute and one-week ingestion of paraxanthine (the compound that caffeine is primarily converted into after ingestion) [33,57], as well as ashwagandha [58], appears to improve short-term memory, reaction times, and/or errors in healthy individuals.…”