(OR14-06-23) Mealworms As Alternative Protein Reduced Weight Gain, Improved Blood Lipid Profiles, and Altered Adipose and Hepatic Gene Expression of Diet-Induced Obesity Mice

Objectives: Insect-based proteins have been identified as sustainable, high-quality protein sources that may be used as alternatives to conventional proteins. Studies have also shown that a high-protein diet exhibits beneficial effects on obesity by modulating satiety and energy metabolism. We aimed to determine the effects of yellow mealworm (Tenebrio molitor)- and lesser mealworm (Alphitobius diaperinus)-based proteins on the body weight (BW), serum metabolites, and liver and adipose tissue histology and gene expression profiles of diet-induced obesity mice.

Methods: Male C57BL/6J mice were fed a high-fat diet (HFD; 45% kcal from fat) for 8 wk to induce obesity and metabolic syndrome that was confirmed by intraperitoneal glucose tolerance tests (IPGTT) at 20 wk of age. Obese mice were randomly assigned to 1 of 5 treatments (n=10/group) for 8 wk following a 1-wk diet transition: HFD: HFD control diet based on casein protein; B50: HFD where 50% protein derived from whole lesser mealworm; B100: HFD where whole lesser mealworm was the sole protein source; Y50: HFD where 50% defatted protein derived from yellow mealworm; Y100: HFD where defatted yellow mealworm was the sole protein source. Lean mice (n=10) fed a low-fat-diet (LFD; 10% kcal from fat) were also included. Food intake, BW, body composition, and IPGTT were measured over time. After 8 wk, serum was collected, and perirenal adipose depot and liver tissue samples were collected for gene expression, histopathology, and triglyceride analysis.

Results: After 8 wk, mice fed Y50, B100 and Y100 had a lower (P < 0.05) BW change rate than mice fed HFD. Obese mice fed mealworm-based diets had increased (P < 0.05) serum HDL and reduced (P < 0.05) serum LDL concentrations, and reduced (P < 0.05) LDL/HDL ratio. Mice fed mealworm-based diets had increased (P < 0.05) expression of genes related to immune response and antioxidants in the liver, and reduced (P < 0.05) expression of genes associated with chemoattractants, inflammation, and apoptosis in adipose tissue. Mealworm-based diets also altered (P < 0.05) glucose and lipid metabolism genes in the liver, and to a lesser extent, in adipose tissue.

Conclusions: Mealworms may not only serve as an alternative protein source, but may confer beneficial health effects in diet-induced obesity mice.

Funding Sources: Funding was provided by Ÿnsect.