Alexander Krokedal Rønnevik:
Effect of various protein sources on body weight development

Date: 01-08-2014    Supervisor: Karsten Kristiansen & Lise Madsen

Background: Due to the increasing prevalence of obesity, finding effective dietary strategies for weight loss and weight maintenance is of great interest. High protein diets are reported to protect against diet-induced obesity, however less is known about how different protein sources affect body weight regulation. We aimed to investigate how various protein sources influenced body weight development and glucose metabolism by feeding obesity prone male C57/BL6 mice various protein sources in different background diets.

Results: In high fat/high sucrose diets (HF/HS), high fat/high protein diets (HF/HP), and Western diets, consumption of lean meat promoted obesity compared to lean seafood and casein.

Consumption of lean meat stimulated accretion of fat mass independent of energy intake when used as the protein source in (HF/HS) diets and most likely due to decreased energy intake when used as the protein source in (HF/HP) diets and Western diets. Consumption of lean seafood increased spontaneous locomotor activity when provided as the protein source in the Western diet and showed a tendency to increase spontaneous locomotor activity when consumed in a (HF/HS) diet compared to lean meat. In comparison to lean seafood, the consumption of lean meat resulted in decreased glucose tolerance when used in both HF/HS- and HF/HP diets. The consumption of lean meat also decreased glucose tolerance when used as the protein source in a Western background. The decreased glucose tolerance associated with the consumption of lean meat in Western background diets was only evident with free access to the diets, most likely due to differences in body composition.

We purpose that the beneficial effects of lean seafood consumption in relation to body weight regulation may be due to an enrichment of the amino acids taurine and glycine.

Conclusion: In summary, our results show that consumption of lean seafood is less obesogenic than lean meat. The benefits of lean seafood consumption were associated with increased spontaneous locomotor activity and possible increased satiety.