The aim of the study is to investigate the effects of milk fat globule membrane (MFGM) content and intactness on postprandial metabolic response to a high-fat meal in humans.

The investigators hypothesize that MFGM content and intactness alters the postprandial lipid profile and substrate metabolism in healthy individuals after consumption of a high-fat meal.

The subjects will be invited for four visits in total: one screening visit and three test days separated by a one-week washout period. At the test days, subjects will consume two high-fat meals composed of milk fat with intact MFGM, destroyed MFGM, and without MFGM, respectively. The first meal will be consumed as breakfast and the second meal will be consumed as lunch. Test meals will be isocaloric and with similar macronutrient composition. The meal will consist of a sandwich with a butter-like dairy product.

The three trial days will be completely alike, besides the interventions.

Subjects will arrive at the research lab the night before test day and stay inside a metabolic chamber to acclimatize.

The participants will have one intravenous (iv.) access placed in the elbow on the three trial days where blood samples will be collected at 15, 30, 60, 90, 120, 150 and 180 min after each test meal (breakfast and lunch).

Immediately after consuming each of the two test meals, the subjects will take 1,500mg paracetamol to determine ventricular emptying rate using the acetaminophen test. After this, the subjects can lay in the bed and watch TV, iPad, or work on their laptop.

Before and every hour after consumption of the test meals, the subjects will be asked to fill out an appetite questionnaire (visual analogue scale). At the end of the day the participants will be offered an "ad libitum meal" to measure if MFGM content and intactness influences ad libitum intake of calories at the next meal.

An one-way mixed model of linear regression will be used to compare postprandial area under the curve, ventricular emptying, and ad libitum food intake between the three test days. Secondary outcomes will be analyzed using a two-way mixed model of linear regression with repeated measurements.

Based on the results from a previous study that investigated the effects of the fat and protein structure in dairy products on postprandial triglycerides (20), the investigators will need 11 subjects to detect a 15% decrease in postprandial triglyceride AUC (α=0.05, β=0.80). To account for potential missing values, 12 subjects will be included in total.

Inclusion Criteria:

• 18-40 years
• Written and informed consent
• HbA1c < 48 mmol/l

Exclusion Criteria:

• Medicine with an impact on blood glucose, lipid profile, or blood pressure and birth control pills
• BMI > 30kg/m2
• Affected screening blood sample as evaluated by the clinical responsible investigator
• Severe claustrophobia
• Lactose intolerance
• Doesn't speak and understand Danish
• Commitment to special diets