Objective: To investigate the effect of krill oil (KO) supplementation during alternate-day fasting (ADF) on body composition and muscle function in healthy adults with overweight.
Methods: In a randomized trial, during the 8-week ADF, participants consumed four capsules per day containing krill oil (KO group) or vegetable oil (placebo group). Each capsule of KO contained 191 mg EPA, 94 mg DHA, 78 mg choline, and 100 mcg astaxanthin. Body mass, fat-free mass (FFM), and handgrip strength (HGS) were measured before and after the intervention. Data were analyzed using ANOVA.
Results: The study was completed by 41 (25 women and 16 men) participants (age: 39 ± 10 years, BMI: 31.1 ± 4.2 kg/m2). Body weight reduction was not different (p > 0.05) between groups (KO, -4.6 ± 1.4 kg; Placebo, -4.5 ± 1.9 kg). The KO group had no change (p > 0.05) in FFM (-0.2 ± 0.9 kg) or HGS (-0.2 ± 0.5 kg). The placebo group experienced a reduction (p < 0.05) in FFM (-1.2 ± 2.0 kg) and HGS (-0.9 ± 0.7 kg). Changes in FFM and HGS were different (p < 0.05) between groups.
Conclusions: KO supplementation during body weight loss attenuates the decline in FFM and muscle strength.
Trial registration: ClinicalTrials.gov Identifier (NCT06001632).
Keywords: body composition; caloric restriction; long‐chain n‐3 polyunsaturated fatty acids; muscle function; weight loss.
© 2025 The Author(s). Obesity published by Wiley Periodicals LLC on behalf of The Obesity Society.