This randomized clinical trial was carried out from January 2017 to December 2017 at the facilities of the Catholic University of Murcia. Written informed consent was required from each patient. The protocols of the present clinical trial follow the CONSORT standards. To measure the impact of cognitive training on weight loss in overweight / obese subjects, a double-blind study (de facto masking) was designed.

Both the participants and the statistical assessors were unaware of the study hypothesis. Participants were unaware of treatments and possible assignments between groups, and only those subjects who were randomly assigned to the cognitive training group were informed that such training was part of dietary therapy.

The principal investigator of the present study (J.J.H.M.) carried out the randomization, with the assistance of the Microsoft Excell program, with the help of a macro designed in Visual Basic® for that purpose.

The randomization divided the subjects into two groups, as they were treated with a hypocaloric diet plus 12 nutrition education sessions (CONTROL group) or a group that were treated with a hypocaloric diet plus 12 sessions of cognitive training (COGNITIVE group).

In order to obtain a similar size in both groups, a randomization in blocks with a 1: 1 allocation ratio was performed.

Cognitive performance measures were performed before and after training. One week before the beginning of the cognitive and dietary intervention, the participants performed a series of cognitive tests. After 12 weeks of both dietary and cognitive intervention, participants were reexamined to measure performance on neurocognitive tests.

Inclusion Criteria:

• Present a BMI> 27 kg / m2, and want to be part of the study voluntarily

Exclusion Criteria:

• subjects with diabetes mellitus type 2
• subjects with a history of a cardiovascular event (acute myocardial infarction, intermittent claudication, etc.)
• subjects with kidney or liver failure or some other significant pathology (cancer)
• subjects under pharmacological treatment that could affect body weight (corticoids, thyroxine, etc.)
• subjects who were on a diet or had been on a diet at least 6 months before their participation in the study were also excluded.

Randomization was performed by the principal investigator. The interventions were carried out individually, so the participants were unaware of the existence of another study arms.