This is an open label, non-randomized, interventional, single arm study.

The primary objective is to assess whether the MAG oil-containing study formula is well tolerated and safe when used as an ONS in healthy adolescents.

Hypothesis: The study product will be safe and well tolerated in healthy adolescents (as previously observed in adults).

Secondary objectives:

1. Describe the frequency and characteristics of possible gastrointestinal intolerance symptoms
2. Describe stool characteristics specifically stool frequency and consistency
3. Describe changes in anthropometric parameters, particularly weight and body mass index (BMI)
4. Describe changes in blood parameters of lipid metabolism
5. Describe changes in hematological and serum biochemistry parameters
6. Describe daily ONS intake and overall compliance

Inclusion Criteria:

1. Healthy volunteers aged 12-17 years
2. BMI range between the 10th and 90th percentile according to the Swiss growth charts with a minimum body weight of 40 kg.
3. Deemed able to comply with study protocol for the study period
4. Able to obtain written informed consent from participants and legally authorized representative(s)

Exclusion Criteria:

1. Pre-existing chronic medical or psychiatric conditions.
2. History of a chronic gastrointestinal disorder (e.g., inflammatory bowel disease, irritable bowel syndrome, celiac disease etc.), or chronic or recurrent gastrointestinal symptoms, including self-reported symptoms such as abdominal pain.
3. Recent episode of an acute gastrointestinal illness with significant gastrointestinal symptoms in the 7 days prior to enrolment.
4. History of chronic constipation (with passage of fewer than 3 spontaneous bowel movements per week on average or history of painful or hard bowel movements), OR chronic or intermittent diarrhea with loose or watery bowel movements ≥ 3 times per day.
5. Colonoscopy or other bowel cleansing procedures within 4 weeks prior to enrolment.
6. Prior use of prescription medication(s), in particular antibiotics, antiacids, laxatives, antidiarrheal agents or other medications impacting gastrointestinal transit time, within 3 weeks prior to enrolment.
7. Significant medical or surgical event in the past 3 months potentially interfering with study procedures and assessments.
8. Subjects following a weight loss program including a low-carbohydrate or low-fat diet, ketogenic diet, intermittent fasting, or any other special diet.
9. Known food allergy in particular cow's milk protein allergy or known/suspected hypersensitivity or intolerance to any other ingredients in the study product. Subjects experiencing gastrointestinal symptoms when consuming dairy products or avoiding dairy in their diet should not participate in the study.
10. Subjects taking energy or protein supplements.
11. Known alcohol or substance abuse.
12. Pregnant or lactating females or having given birth in the past 6 months prior to enrolment. Pregnancy will be ruled out by performing a standard urine dipstick test to female participants of childbearing potential prior to enrolment.
13. Family or hierarchical relationships with Clinical Innovation Lab staff