The Proportion of Dietary Protein Digested as Measured by the Dual-isotope Method.

Study Overview
=================
Brief Summary
-----------------
The retrospective cohort study will compare the prevalence of sarcopenia and associated factors between older patients who have undergone bariatric surgery and older patients with obesity without previous bariatric surgery.

Detailed Description
-----------------
The aim of the study is to compare the prevalence of sarcopenia and nutritional status between adults older than 65 years who have previously undergone bariatric surgery and patients with obesity but without previous bariatric surgery. Current sarcopenia will be assessed during a cross-sectional assessment after surgery using the criteria from the European Working Group on Sarcopenia in Older People (EWGSOP).

Official Title
-----------------
The Proportion of Dietary Protein Digested as Measured by the Dual-isotope Method.

Conditions
-----------------
Aging, Overweight and Obesity, Bariatric Surgery Candidate, Protein Malabsorption

Intervention / Treatment
-----------------
* Other: Dual isotope method


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Signed informed consent Age 65 years or older Group 1 & 2: Previous bariatric surgery for obesity 1 - 10 years ago Group 3: No previous weight loss surgery Exclusion Criteria: Current diagnosis of cancer Advanced organ failure, including chronic kidney disease Stage 5, liver cirrhosis Stage 3, intestinal failure, heart failure stage D, or chronic obstructive pulmonary disease stage 4. Immobility Neuromuscular degenerative conditions Gastrointestinal conditions including coeliac disease, Crohn's disease, previous resection of the small intestine, gastroparesis Unable to follow the procedures of the studies due to cognitive impairment such as diagnosed dementia. Allergy/intolerance to milk, or soy or spirulina

Ages Eligible for Study
-----------------
Minimum Age: 65 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
Accepts Healthy Volunteers

Study Plan
=================
How is the study designed?
-----------------

Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Group 1: Patients over 65 years of age who had undergone Roux-en-Y bariatric surgery<br>Group 1: Patients over 65 years of age who had undergone Roux-en-Y bariatric surgery | Other: Dual isotope method<br>* Dual isotope method<br>|
| Group 2: Patients over 65 years of age who had undergone sleeve gastrectomy surgery<br>Group 2: Patients over 65 years of age who had undergone sleeve gastrectomy surgery | Other: Dual isotope method<br>* Dual isotope method<br>|
| Group 3: Patients over 65 years of age without previous bariatric surgery<br>Group 3: Patients over 65 years of age without previous bariatric surgery | Other: Dual isotope method<br>* Dual isotope method<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The proportion of dietary protein digested as measured by the dual-isotope method. | The proportion of dietary protein digested as measured by the dual-isotope method. | 3,5 hours |