Multidimensional Phenotyping Towards Personalized Preventive Nutritional Support for Elderly People

Kinetics of change in postprandial blood glucose over a period of 4 hours following home consumption of four types of test meals by continuously monitoring blood glucose

The investigators' objective is to have a good understanding of eating habits: estimation of precise food intake over three days but also long-term eating habits, preferences for sweet foods, salty foods, fatty foods. Participants will also be questioned about their general appetite, their neophobia, their culinary habits. An effort will be made to estimate polyphenol intake through specific questions.

The participants will be offered drinks containing either water (n=2) or salted water (n=8), with various concentrations of salt. The objective is to determine which drinks contain salt or not. The score will vary from 0 (only bad answers) to 8 (only good answers). A score of 8 thus means that the taste abilities are good.

Six groups of 4 vials will be presented to the participants. For each group of 4, only one vial has an odor. The first step will be to find the vial that does contain an odor. Then, the participant will have to identify the odor, choosing among 4 proposed odor. The score will increase with the number of vial found and the number of correct odor identification. It will thus vary from 0 to 8. If a participant has a score of 8, it means that he could detect each time in which vial there was an odor, and could each time identify the odor. Thus a score of 8 denotes very good olfactory abilities.

The time to walk 4 m will be measured.

The time to stand up 5 times from a chair will be measured.

The maximum tolerated muscle power will be measured on a cycloergometer

The maximal isometric strength of the quadriceps will be measured on an isometric measuring bench.

The objective is to assess the amount of time usually spent by the participant for physical activity and for sedentary activities, the intensity of activities, through 28 questions. This questionnaire will give a categorical score, with 3 levels of physical activity: 1) Low: no physical activity or only low intensity activities. 2) Moderate: 3 or more days of intense activity lasting at least 20 min per day, or 5 days or more of moderate intensity activity and/or walking for at least 30 minutes per day, or 5 days or more of activity combining walking, moderate or high intensity activities. 3) Intense activity at least 3 days per week or 7 days or more of activity combining walking, moderate or high intensity activities

Lean body mass will be measured by multi frequency electrical bio impedance (Bodystat QuadScan 4000). A weak electric current is delivered to the subject through electrodes, and the voltage is measured in order to calculate impedance (resistance and reactance) of the body. Most body water is stored in muscle. Therefore, if a person is more muscular there is a high chance that the person will also have more body water, which leads to lower impedance. Using the weight of the participant, through calibration curves, the system then calculates total body water, total body fat mass, and total body lean mass.

Fat body mass will be measured by multi frequency electrical bio impedance (Bodystat QuadScan 4000). A weak electric current is delivered to the subject through electrodes, and the voltage is measured in order to calculate impedance (resistance and reactance) of the body. Most body water is stored in muscle. Therefore, if a person is more muscular there is a high chance that the person will also have more body water, which leads to lower impedance. Using the weight of the participant, through calibration curves, the system then calculates total body water, total body fat mass, and total body lean mass.

Peripheral endothelial function of the participants will be assessed by tonometry using the Endo-PAT X system (Itamar Medical Ltd) before and after induction of post-occlusive reactive hyperemia. Endothelium-induced changes in vascular tone are measured at the fingertip using a pair of single-use plethysmographic sensors. The result obtained is the Reactive Hyperemia Index (RHI, %) which corresponds to the ratio between the amplitudes of the PAT® (Peripheral Arterial Tonometry) signal during hyperemia and the basal amplitudes of the occluded side, normalized by the values of the control arm. The values will be considered as normal if inferior to 1.67, and abnormal if higher than 1.67.

Microvascular stiffness (=Augmentation Index) of the participants will be assessed by tonometry using the Endo-PAT X system (Itamar Medical Ltd). Augmentation Index (AI) will be calculated from the shape of the pulse wave recorded in basal conditions. This measurement is a recognized marker of cardiovascular risk. The AI value is inversely proportional to the stiffness of the vessels. The scale of the measurement is the following:

Values between 20-80: healthy degree of arterial flexibility. Values between 81-100 : increased cardiovascular risk Values over 100: high cardiovascular risk.

Oral status will be assessed through the Nordic Orofacial Test - Screening (NOT-S), which is a screening and evaluation tool for orofacial motor dysfunctions and disorders. It includes two parts: 1) "Maintenance" part containing 6 sections: sensory function, breathing, habits, chewing and swallowing, drooling, and dry mouth (I-VI); 2) "Examination" part comprising 6 sections: face at rest, nasal breathing, facial expression, function of the masticatory muscles and jaws, oral motor functions, and articulation of speech. The NOT-S total score ranges from 0 (no dysfunction) to 12 (high dysfunction). For each section, from the moment the subject answers "Yes" to one of the questions, the box is checked and results in a score of 1 in the last right column of the questionnaire.

The cognitive abilities of the participants will be assessed using the CANTAB®, using a computer under supervision. This method makes it possible to assess 1) episodic memory; 2) verbal recognition memory, that is, immediate and delayed memory for verbal information; 3) Spatial working memory, which requires the retention and manipulation of visuospatial information. 4) The spatial span task (CANTAB spatial spam), which evaluates the maximum amount of information that the subject is capable of recalling after a single presentation.

Participants' depressive nature will be assessed using the Geriatric Depression Scale (GDS) test. It is a self-questionnaire which contains 15 items, each with a binary Yes-No response. It is a commonly used tool to assess the presence of depressive symptoms in older adults. A score of 0 to 5 is considered normal. A score between 5 and 9 indicates a high likelihood of depression, and a score between 10 and 15 almost always indicates depression.

The socio-economic status of participants will be assessed using the EPICES scale (Évaluation de la Précarité et des Inégalités de santé dans les Centres d'Examens de Santé) which was developed in France by the National Institute of Prevention and Education for Health . This scale is used in public health to assess the social precariousness of individuals, which takes into account the multidimensional nature of precariousness. The main interest of the EPICES score consists of understanding populations which, while escaping the traditional administrative indicators of precariousness, present the same health risks. The EPICES score is based on 11 questions which summarize 90% of a subject's precarious situation. The answer to each question is assigned a coefficient, the sum of the 11 answers gives the EPICES score. The score is continuous, it varies from 0 (absence of precariousness) to 100 (maximum of precariousness).

Participants' self-esteem will be assessed using the Rosenberg Self-Esteem Scale. It is a psychometric tool widely used in psychology research, social sciences and clinical settings. It consists of 10 questions to which respondents are asked to indicate their degree of agreement or disagreement using a 4-point Likert scale, ranging from "strongly disagree" to "strongly agree". The questions are designed to assess overall self-perception and personal esteem. The score between 10 and 40 which are interpreted according to specific thresholds.Higher scores indicate higher self-esteem.

To have a better understanding of the characteristics of the participants' intestinal function, they will have to complete an intestinal transit diary. Such a diary is a tool used to record a person's stool habits and characteristics over a period of time. It is often used in the field of gastroenterology and nutrition to assess the functioning of the digestive system. Participants will note every day for 15 days: the frequency of stools, noting each time the time they had a bowel movement, as well as the consistency of stools based on the Bristol visual scale. which categorizes 7 types of stools, ranging from the hardest to the softest. Experts consider types 1 and 2 to be uncharacteristically hard and indicative of constipation, while types 6 and 7 are unusually loose and may indicate diarrhea. Medical professionals generally consider types 3, 4, and 5 to be the most typical. Overall, a qualitative assessment of intestinal function will be made, with no calculated score.

One sample of stool will be taken and analyzed by metagenomic.

These measurements will be made 1) in the post-absorptive state, 2) after the ingestion of 4 standards test meals, 3) after the ingestion of a sweet and fatty meal.

These measurements will be made 1) in the post-absorptive state, 2) after the ingestion of 4 standards test meals, 3) after the ingestion of a sweet and fatty meal.

These measurements will be made in the post-absorptive state.

These measurements will be made 1) in the post-absorptive state 2) after the ingestion of a protein rich test meal.

These measurements will be made 1) in the post-absorptive state 2) after the ingestion of a sweet and fatty meal.

These measurements will be made 1) in the post-absorptive state 2) after the ingestion of a sweet and fatty meal.

These measurements will be made 1) in the post-absorptive state 2) after the ingestion of a sweet and fatty meal.

These measurements will be made in the post-absorptive state

These measurements will be made in the post-absorptive state

These measurements will be made 1) in the post-absorptive state 2) after the ingestion of a sweet and fatty meal.

These measurements will be made in the post-absorptive state.