Oslo, July 17 2025: A new study, led by the University of Glasgow’s School of Medicine, Dentistry and Nursing, shows that supplementation with krill oil during an alternate-day fasting diet helps reduce the associated decline of fat-free mass, primarily muscle mass, and muscle strength. The study, published in the journal Obesity, is the first of its kind to investigate the effects of krill oil on muscle mass and strength during diet-induced weight loss.
Growing global interest in weight-loss interventions – from calorie-restricted diets to pharmacological approaches such as GLP-1 receptor agonists – has brought increased attention to the potential health implications of rapid weight reduction. One concern is the simultaneous loss of skeletal muscle, which can negatively impact metabolic health, physical function, and long-term weight maintenance. While this study did not include participants on GLP-1 medication, the findings provide relevant insights for a broad range of weight-loss scenarios.
“While losing weight is often a good thing one of the unintended consequences is that we don’t only lose fat, but we also lose muscle. In this study we have found that krill oil can help to preserve our muscle mass and strength as we lose weight. As maintenance of muscle is very important for our overall health and quality of life, these are extremely exciting findings,” says Dr. Stuart Gray, a Professor at the University of Glasgow and co-author of the study.
Clinical study background
The study was based on the premise that weight loss during a fasting diet can lead to a decline in muscle mass, which can negatively impact muscle strength. The scientists at the University of Glasgow hypothesized that krill oil, as a source of long-chain omega-3 poly- unsaturated fatty acids, could help minimize this decline.
They put this theory to the test by enrolling 52 adult participants (between 25-65 years of age with above average BMI) in the randomized placebo-controlled trial, using krill oil and placebo supplements supplied by Aker BioMarine.
The participants received either 4g of Superba Boost krill oil per day or 4g of vegetable oil per day (placebo) both before and during the weight loss period. During fasting days, participants consumed no more than 500 Kcal during a two-hour window. On feeding days, participants were allowed to eat normally but were told to avoid overeating.
Results of the trial
The 41 participants who completed the trial underwent several tests following the weight loss period, including handgrip strength, chair rising, body composition and a fatty acid composition analysis. The key results included:
- The loss in muscle mass was lower in the krill oil group compared to the placebo group
- The resulting loss in handgrip strength was lower in the krill oil group compared to the placebo group.
- The amount of time to rise out of a chair was shorter for participants taking the krill oil supplements.
- The reduction in systolic blood pressure was greater in the krill oil group than in the placebo group.
- The amount of fatty acids (EPA, DHA) and the omega-3 index were higher among participants in the krill oil group.
Following this experiment, the scientists concluded that 4g per day of krill oil during a period of weight loss can help reduce losses in muscle mass and strength, making it a viable strategy to mitigate some of the associated unwanted effects. They also noted that future studies are recommended to explore the underlying mechanisms behind the impact of krill oil in terms of preserving muscle function.
“We are pleased to continue our work with the University of Glasgow to further explore krill oil and its positive effects on muscle mass and function,” says Line Johnsen, SVP Human Health Ingredients R&D, Aker BioMarine. “We have previously conducted scientific studies with Dr. Gray and his team to show how the important nutrients found in krill impact muscle strength and mass with age, and this follow up study helps strengthen our understanding of this area.”
Explore the complete University of Glasgow study here.
About Aker BioMarine
Aker BioMarine is a leading human health innovator that develops krill-derived products for consumer nutrition. The company has a strong position in its industry and is the world's leading supplier of krill, the natural, powerful and health promoting source of nutrients from the pristine waters of Antarctica. Our ingredient portfolio consists of Superba Krill Oil, Lysoveta, FloraMarine, and PL+, as well as our consumer brand, Kori Krill. Our innovative approach also extends into spin-offs like AION (reduce and recycle plastic waste across industries), and Understory (our protein brand). Aker BioMarine is listed on Oslo Stock Exchange (AKBM). More information is available at www.akerbiomarine.com.
About the University of Glasgow
The University of Glasgow is a top world 100 University (THE, QS) and the current Times and Sunday Times Good University of the Year 2022. The University is a member of the prestigious Russell Group of leading UK Universities and has an annual research income of more than £180m. As a world-leading, research-intensive University, the University of Glasgow is committed to contributing towards the UN’s 17 Sustainable Development Goals (SDGs) and has committed to carbon neutrality by 2030. Glasgow was the first UK University to declare it would divest from fossil fuels within a decade and the first in Scotland to declare a Climate Emergency. In 2021, the University of Glasgow received a Queen’s Anniversary Prize for its national service to the Covid-19 pandemic.