Comparison Between Olive Oil and Palm Oil-enricHed chOCOlate Spreads (CHOCO) in Healthy Subjects

This clinical trial aims to investigate if extra virgin olive oil (EVOO) or palm oil enriched chocolate spread snacks consumption lead to differential insulin resistance status in young, healthy subjects. Such effect includes difference in a) plasma ceramides, b) glucose metabolism markers, c) lipid profile, d) inflammatory markers, e) hunger/satiety hormonal markers and visual analogue scale.

Exceeding intake of foods high in palmitic acid, abundant in Palm Oil, has been associated with lipotoxicity, a condition featured by high toxic lipids in the body such as ceramides, which ultimately can lead to insulin resistance and therefore to diabetes and increased cardiometabolic risk through the promotion of atheroma plaque formation.

On the other hand, foods high in oleic acid, rich in extra virgin olive oil EVOO and typical of the Mediterranean diet, has been related to reduced insulin resistance and inflammatory state, with proved protective effects against metabolic diseases such as diabetes, hypercholesterolemia and cardiovascular disease.

Therefore, this clinical trial aims to assess potential metabolic differences in relation to daily consumption of EVOO-enriched chocolate spread in comparison with a Palm oil-enriched chocolate spread.

The investigators, therefore, aimed to evaluate the impact of fourteen days consuming the two different oils added to the same chocolate spread in terms of the composition of plasma ceramides as the primary outcome; and as secondary outcomes, changes in glucose metabolism markers (Glucose, Insulin, HOMA-IR), in LDL, total cholesterol, Triglycerides, HDL levels, in inflammation Markers (CRP, IL-6, TNF-a) and in the appetite-regulating hormones (Leptin, Adiponectin, GLP-1, Ghrelin, PYY and Oxyntomodulin) and in the visual analogue scale (VAS) analysis.

Both chocolate spreads have an identical composition with the exception of fat content (EVOO vs. Palm Oil).

Once eligibility will be assessed through screening and medical anamnesis, twenty healthy subjects will be enrolled and randomized based on a double-blind, controlled, crossover design.

They will undergo a 1-week "run-in diet" phase before the randomization (V1) and the inception of a 14-day interventional diet phase 1. A compliance visit (V2) will be performed on day-7 to ensure that daily compliance is available from each participant (i.e., that the chocolate spread provided is eaten daily). On day 14, the participants will undergo a meal Challenge (V3), consuming the chocolate spread jar (challenge meal) and, serial blood withdrawals will be performed at times 0 ', 30', 60 ', 90', 120 'and 180 ' and, at the same time points, subjects will be required to complete a Visual Analogue Scale (VAS) for monitoring hunger and satiety. Subsequently, the subjects will undergo another week of run-in diet, identical to the previous run-in diet, to be then allocated to another fourteen days of the opposite treatment to the previous one, with the same described methods. Also, in all the visits physical examination with the collection of anthropometric data and body composition analysis will be performed.

Study subjects will be provided structured meals, according to isocaloric diets designed by nutritionists based on subjects' energy requirements. Meals will be prepared by specific canteens and consumed on-site or collected daily in individual meal boxes. Patients will be asked to fill daily food diaries, in order to ensure all of the daily food is ingested (including the chocolate spread), as well as to assess any leftovers.

Eligibility Criteria:
Inclusion Criteria:

* Healthy volunteers of both genders.
* Aged \> 18 years.
* Body mass index ranging from 18 to 29.99 kg/m2.
* Subjects able to provide written informed consent.

Exclusion Criteria:

* Diagnosis of diabetes. defined as per the Italian Society of Diabetology guidelines. fasting glucose twice greater than 126 mg / dL and/or random glucose greater than 200 mg / dL.
* Subjects being treated with oral and/or injectable hypoglycemic and/or insulin-sensitizing agents
* Subjects undergoing therapy with synthetic cholesterol-lowering agents (statins and/or fibrates) and/or cholesterol-lowering nutraceuticals (berberine and/or monacolin k)
* Individuals with triglycerides greater than 200 mg/dL
* Subjects with LDL greater than 159 mg/dL
* Moderate or major renal impairment (and GFR \<60 mL/min)
* Hypertensive subjects and/or subjects being treated with antihypertensives
* Subjects receiving omega 3 supplements.
* Pregnancy and/or breastfeeding.
* Coronary cardiovascular disease.
* Stroke and heart failure.
* Celiac disease.
* Malabsorption.
* Irritable bowel syndrome.
* Chronic inflammatory bowel disease.
* Present alcoholism or drug abuse or use of medicines whose dose may change during the study or when there is an intention to start a new therapy.
* Individuals with an allergy to hazelnuts or any of the ingredients present in the chocolates under study.
* Neurological or psychiatric pathologies
* Subjects who cannot participate in the study for any reason
* Infectious diseases such as HIV, hepatitis or chronic infections
* Any uncontrolled endocrine pathology such as Cushing's. Acromegaly. etc.
* Any existing cancer and/or lymphoma
* Eating disorders such as anorexia and bulimia
* Previous bariatric surgery or gastrectomy
* Individuals with pacemakers
* Not consuming the chocolate spread for more than three days