Dietary protein intake of adequate quality is essential for human health. Traditional animal source foods play a key role in providing high quality protein but are associated with a high burden on the environment. Therefore, viable alternative protein sources are needed to be able to meet human nutritional needs for the rapidly increasing world population, while keeping food production within the planetary boundaries. T. molitor (Yellow Mealworm larvae) is a sustainably produced and commercially available edible insect, which contains a high quantity of protein with a favorable amino acid profile. Protein quality evaluation considers the amino acid composition as well as the ileal digestibility of the food's individual amino acids, to assess if human dietary requirements for essential amino acids can be met by the protein source. The present study will measure the digestibility of essential amino acids from T. molitor with a minimally invasive dual stable isotope tracer method that follows a plateau-fed test meal protocol. T. molitor will be intrinsically labelled with the stable isotope deuterium (2H), which will be given along with a reference amino acid mixture of known digestibility, labelled with the stable isotope carbon-13 (13C). Based on the results from the present study, protein quality of T. molitor as a protein source for human nutrition can be assessed, allowing a direct comparison of this novel protein source to other protein sources, such as meat and legumes.

Inclusion Criteria:

• Female aged between 18-45 years
• Normal BMI (18.5 - 25 kg/m2)
• Body weight < 60 kg
• Signed informed consent
• Able to communicate and comprehend English
• Are open-minded towards consuming insect-based meals

Exclusion Criteria:

• Anaemic (Hb < 12 g/dL)
• Inflammation (CRP > 5.0 mg/L)
• Pregnancy or intention to become pregnant during the study or within 30 days after the discontinuation of the study intervention
• Lactating up to 6 weeks before the study initiation
• Chronic digestive, renal and/or metabolic diseases
• Antibiotics in the last 4 weeks prior to the study and during the study
• Mineral and vitamin supplementation in the last 2 weeks prior to the study
• Chronic medication intake (except for oral contraceptives)
• Daily exercise routine of high intensity
• Blood transfusion, blood donation or significant blood loss (accident, surgery) over the past 4 months
• Participation in any clinical study within the last 30 days
• Food allergies, especially hypersensitivity to crustacea, dust mites, sea food, gluten, milk, or eggs
• History of serious illness or infection within 3 months of the study
• Cigarette smoking (> 1 cigarette per day)
• Difficulties with blood or breath sampling
• Participants who cannot be expected to comply with study protocol (e.g., not available for the full 8.5 hours of the study day or unable to follow fasting period)
• Inability to understand the information sheet and the informed consent form due to cognitive or language reasons