Effect of a non-energy restricted ketogenic diet on cognition in sedentary healthy young adults

Khattak, Munaza and Habib, Syed Hamid and Irfan, Mohammad (2026) Effect of a non-energy restricted ketogenic diet on cognition in sedentary healthy young adults. PHYSIOLOGY INTERNATIONAL, 113 (1). pp. 81-96. ISSN 2498-602X

Preview

Text 2060-article-p81.pdf - Published Version Available under License Creative Commons Attribution Non-commercial. Download (506kB) | Preview

Abstract

Background: Ketogenic diet (KD) is increasingly recognized as a strategy to combat obesity. However, its effects on cognition in sedentary healthy young adults remain underexplored. Methods: In a quasiexperimental design, 186 participants were screened, 78 excluded based on predefined criteria, leaving 108 healthy adults (age 25–45 years, BMI 18–29.9 kg m2 , sedentary <5,000 steps/day) assigned to either KD group (<5% carbohydrates, 20–25% protein, 70–75% fat; n 5 54) or control group (regular diet ∼50–65% carbohydrates; n 5 54). Participants underwent a 4 weeks’ dietary intervention. Cognitive domains were assessed at baseline and post intervention using validated computer-based test battery. Pre, mid and post weight, BMI, blood ketones and fasting glucose were also measured. Forty-three participants in the KD group and 38 in the control group completed the trial. Results: Four weeks of non-energy restricted KD improved processing speed, semantic memory, working memory, episodic memory, fluid cognition, crystallized cognition and overall cognitive composite scores (all P ≤ 0.001) versus controls. Attention and inhibitory control (P 5 0.46) and cognitive flexibility (P 5 0.21) showed no significant differences. Blood ketones increased (0.12–1.32 mmol L1 , P < 0.001) in KD participants versus controls (0.118–0.105 mmol L1 , P 5 0.94). KD reduced weight (P < 0.001), BMI (P < 0.001) and fasting glucose (P < 0.001). Post intervention ketones predicted cognitive gain in most cognitive domains except attention & inhibitory control and cognitive flexibility. Conclusion: Short term KD intervention enhances memory, processing speed, fluid, crystallized and overall cognitive function composite scores in sedentary healthy adults.

Actions (login required)

Edit Item