BACKGROUND: Several reports have observed that the alteration of normal biological rhythms is associated with obesity development. In this regard, those subject with the preference for evening seems to be prone to develop obesity. However, the current treatment of obesity does not take into account these aspects OBJECTIVE: To evaluate whether a diet adjusted to patient's chronotype is more effective than the current dietary recommendations.

SUBJECTS/METHODS: 209 subjects take part in a randomized, double-blind clinical trial. 104 subjects followed a typical hypocaloric dietary treatment (CONTROL) and the other 105 subjects undergone a diet with a daily caloric distribution adjusted to their chronotype (CHRONO).

CONCLUSIONS: A chronotype-adjusted diet may be a promising alternative to the classical hypocaloric dietary treatment since the investigator's data indicate a higher effectiveness regarding weight loss when the diet was adjusted to the patient's chronotype.

Inclusion Criteria:

• students or staff of the Catholic University of Murcia (UCAM), with an age ranged between 18 and 65 years old

Exclusion Criteria:

• clinically significant illnesses (including type 2 diabetes, chronic heart failure, hepatitis and cancer)
• those taking any medications known to affect body weight (thyroid hormones, corticosteroids, etc.)
• women in special physiological situations (pregnant, lactating).