Effect of an Antiinflammatory Diet on Postprandial Gene Expression of Mononuclear Cells of Adult Obese Women

A randomized controlled crossover study was conducted. Volunteers underwent to two dietary models for 8 weeks each, including a 2 weeks washout diet between them. The order in which they started the interventions was randomized following a computerized assignment list using Excel software (Microsoft Office 2015, Excel 2013).

The primary endpoint was the postprandial gene expression of nuclear factor kappa B subunit 1 (NFKB1) gene. Based on previous studies , 20 individuals had to be studied to detect a 0.2 difference in the expression of the NKKB1 gene between diets with 0.05 significance level and 80 percentage power (type II error Z 0.2), assuming a 10 percentage drop-out rate.

The recruitment of participants was carried out according to the following steps:

• Review of clinical histories of patients diagnosed with obesity, according to their Body Mass Index, ascribed to the chronic non-communicable diseases program of the Clinica Comfamiliar Risaralda in the city of Pereira Colombia.
• Telephone call to invite the participants who met the inclusion criteria to participate in the study.
• Appointment prior to the start of the study to take a blood sample to corroborate the inclusion criteria. With this sample the following tests were performed: blood glucose, lipid profile, thyroid stimulating hormone (TSH), C-reactive protein ( and complete blood count.

This process was carried out by personnel not involved in the research. The results obtained were compared with the clinical history.

The diets followed during the intervention periods were: (1) a diet consisting mainly of the consumption of fruit, avocado and other vegetables, whole grains and trout typical of the colombian coffee region (FAWGT) (experimental diet), and (2) the usual diet consumed by the participants in their normal lifestyle (UD).

At the beginning of the dietary intervention period, each participant was given an individualized food guide containing the suggested food group and portions, with a wide variety of foods allowed for greater adherence to the diet. In addition, specific times for consumption of the foods and precise instructions for the dietary intervention were given. In addition, the subjects were given a talk advising them how to quantify the portions, which would later be converted into grams according to the procedure described

The food portions were standardized with all the participants using synthetic models, adapted according to the Colombian nutritional guidelines, so that they could provide a more accurate report of the portions consumed during the intervention. In addition, a postprandial studies were carried out at the beginning of the study (pre-intervention) and another after 8 weeks of dietary intervention (post-intervention).

The participants were given an appointment at the health center at 7.00 am, after at least 12 hours of fasting and a 5 day abstinence from alcohol. They consumed a breakfast based on the same composition of the diet in which they were randomized for the dietary intervention period. The blood samples were obtained by veni-puncture at baseline and 4 hours after breakfast. During the postprandial period, the participants did not consume any more food, although they were allowed to drink water. The breakfasts were composed of the following foods: FAWGT diet; whole-grain arepa (with unrefined corn flour), cheese, oats, granadilla, mango, linseed, nuts, almonds, peanuts and yogurt. Usual diet; egg, cheese, butter, whole milk, traditional white arepa (with re-fined corn flour), traditional buñuelo (made from wheat flour with cheese), coffee and sugar.

Before starting the dietary intervention period (Pre-intervention), at the midpoint of the study (week 4) and at the end (week 8), all the participants completed three 24-hour recalls (2 non-consecutive weekdays and one weekend day) to obtain information about food, ingredients and preparations consumed in the same units of measurement (grams).

In addition, a weekly telephone call was made to answer any questions relating to the diet (recipes, menu and quantities) and to motivate adherence to the assigned dietary model.

Moreover, in week four of each intervention, the participants attended the hospital for an interview with the main researcher in order to take anthropometric measurements, evaluate the follow-up of the dietary instructions and answer any questions that may have arisen during the intervention, and motivate them to continue with the study. To collect the information on food consumption, formats and questionnaires previously published by the research group were used.

Inclusion criteria

• Informed consent
• Body mass index (BMI) ≥ 30 Kg/m^2.
• Clinical: hypertensive and dyslipidemic participants.

Exclusion criteria

• Age < 40 or > 65 years
• Patients unable to follow a protocol.
• Psychiatric diseases
• Renal Insufficiency
• Chronic Hepatopathy
• Active Malignancy
• Chronic obstructive pulmonary disease
• Diseases of the digestive tract Endocrine disorders
• Smokers.
• Regular alcohol consumers.
• Participants who were in weight reduction programs
• Prescribed hypolipidaemic medication
• Prescribed anti-inflammatory medication
• Kidney or liver dysfunction.
• Diabetes or other endocrine disorders.
• Chronic inflammatory conditions.
• Patients participating in other Clinical trials (in the enrollment moment or 30 days prior).