Since all the pregnant women in this study have at least one of the following risk factors: obesity, diabetes or hypertension, nutritional follow-up is a standard-care procedure in the Portuguese National Health System, therefore the control group receive usual care from the nutritionist in the hospital.

In addition to the standard-care follow-up in the Portuguese National Health System, the intervention group will have additionally three approaches within the intervention: i) one face-to-face appointment lasting 10 to 15 minutes conducted by a registered dietitian (3rd trimester: 30 - 35 gestational weeks); ii) a 13-page manual that accompanies the dietary education session, which is provided to each participant; and iii) five monthly newsletters sent via e-mail from two weeks after childbirth until the fifth month postpartum.

In the same way as the control group, the intervention group receives standard nutritional care from the hospital nutritionist, since all the pregnant women have at least one of the following risk factors: obesity, diabetes or hypertension, nutritional - standard-care procedure in the Portuguese National Health System.

To assess the effect of the dietary education counseling focused Mediterranean Diet promotion (intervention group) vs nutritional standard-care of the. Portuguese National Health System (Control Group: Standard Hospital Dietary Care)) on the percentage change of the Mediterranean Diet Adherence Screener (MEDAS) score.

The MEDAS score ranges from 0 to 14, with higher scores indicating greater adherence to the Mediterranean Diet. Scores are commonly classified as follows:

• Low adherence: < 7
• Moderate adherence: 7-9
• High adherence: ≥ 10

To assess the effect of dietary education counseling focused on Mediterranean Diet promotion (intervention group) vs control group on cardiac reverse remodeling, evaluated through echocardiographic measurements of cardiac structure and function during pregnancy and postpartum.

Cardiac reverse remodeling will be assessed as the change (Δ) in left ventricular (LV) mass between the third trimester of pregnancy and 6 months postpartum.

Conventional transthoracic echocardiography will be performed using a 3 MHz phased-array probe (ACUSON SC2000 PRIME) by a single operator. Measurements will be obtained from standard parasternal and apical views, according to the European Society of Cardiology recommendations.

Left ventricular mass (g) will be estimated using the following formula:

LV mass = 0.8 × {1.04 × [(LVEDD + PWTd + IVSd)³ - (LVEDD)³]} + 0.6 where: LVEDD = LV end-diastolic diameter PWTdP = posterior wall thickness in diastole IVSd = interventricular septal thickness in diastole

To assess the effect of dietary education counseling focused on Mediterranean Diet promotion (intervention group) vs nutritional standard care of the Portuguese National Health System (control group) on the timing of complementary feeding (solid food) introduction in infants.

At every time points, mothers will be asked using structured parental questionnaires to report the infant's age (in weeks) at the introduction of any solid or semi-solid foods, excluding breast milk or infant formula.

The primary metric will be the infant's age in weeks at first introduction of complementary feeding.