Meal times differ from culture to culture. These differences may influence energy regulation and, consequently, body weight. Current studies support the notion that not only "what" but also "when" the investigators eat may have a significant role in obesity treatment. Recently, it has been shown that eating the main meal of the day, lunch in Spain, late in the day is predictive of difficulty in weight loss and decreased insulin sensitivity. This project aims to study in a Mediterranean population the potential influence of genetics and food timing on obesity, metabolic syndrome and weight loss.
Meal times differ from culture to culture. These differences may influence energy regulation and, consequently, body weight. Current studies support the notion that not only "what" but also "when" the investigators eat may have a significant role in obesity treatment. Recently, it has been shown that eating the main meal of the day, lunch in Spain, late in the day is predictive of difficulty in weight loss and decreased insulin sensitivity. Furthermore, it has been shown that eating late at night when plasma melatonin concentrations are elevated, impairs glucose tolerance, particularly in MTNR1B risk allele carriers. The main objective is to identify the mechanisms underlying the association between the timing of food intake, obesity and metabolic syndrome (MetS) in order to design effective weight loss therapies. The long-term goal is to determine the potential impact of more European, i.e., earlier meal timing on obesity, MetS and weight loss. The challenge for the society is to develop evidence-based dietary interventions incorporating meal timing and genotype to combat the epidemic of obesity and MetS. These goals will be achieved through three specific approaches: * Epidemiological (observational study) (Aim 1): To assess in an obese population (n=5000) who will follow a weight loss program if clock-related (CLOCK, PER2, CRY, etc.) and melatonin-related variants (MTNR1B) interact with the timing of food intake to determine weight loss effectiveness and MetS features. * Interventional (randomized controlled trials) (Aim 2): To determine the internal mechanisms of energy balance and circadian system implicated in the differential effects of food timing (lunch) on weight loss, MetS alterations and the intestinal microbiota (n=25), and to study the potential interaction between meal timing (dinner) and genetic variants MTNR1B for glucose tolerance in obese women (n=100).
Study Type
OBSERVATIONAL
Enrollment
University of Murcia
Murcia, Spain
RECRUITINGTotal weight loss
Body weight will be measured in barefoot wearing light clothes, with a digital scale to the nearest 0.1 kg, at the same time each day.
Time frame: weekly, during the 28 weeks of treatment
Long term weight loss maintenance
Body weight will be measured in barefoot wearing light clothes, with a digital scale to the nearest 0.1 kg.
Time frame: once at least one year after ending the treatment
Food timing
Timing of breakfast, lunch and dinner
Time frame: at baseline
Sleep timing
Habitual sleep timing is estimated using a self-reported questionnaire.
Time frame: at baseline
Siesta timing questionnaire
Habitual siesta timing is estimated using a self-reported questionnaire.
Time frame: at baseline
Individual chronotype questionnaire
With the Morning and Eveningness Questionnaire (MEQ)
Time frame: at baseline
Food habits questionnaire
Variety of food groups is assessed by at 24h recall the day before starting the intervention and by a a seven days dietary record during the intervention. The number of different food items per day will be counted to assess variety of food
Time frame: at baseline
Total energy intake dietary questionnaire
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by at 24h recall the day before starting the intervention and by a a seven days dietary record during the intervention. Daily energy intake will be calculated
Time frame: at baseline
Macronutrient distribution dietary questionnaire
by at 24h recall the day before starting the intervention and by a a seven days dietary record during the intervention. Macronutrient (% from total calories of the diet) and (grams) will be calculated
Time frame: at baseline
Glycemic Index questionnaire
by at 24h recall the day before starting the intervention and by a a seven days dietary record during the intervention. The glycemic index will be calculated by using different composition tables
Time frame: at baseline
Barriers to Weight Loss checklist
A questionnaire will be complete by the participants. The test consisted of 29 questions classified into seven sections: meal recording; weight control and weekly interviews; eating habits; portion size; food and drink choice; way of eating; and other obstacles to weight loss. There are were three possible responses (never 0, sometimes 1, very often 2) to those questions that represented barriers to losing weight, such as ''Have you lost your motivation?'' or ''Do you have binges?'' Questions that represented aids to weight loss, such as ''Do you accurately measure your portions?'' or ''Is absolutely everything written down?'' applied the same score (0 to 2) but with negative signs. A final ''Barriers to Weight Loss'' score is calculated by adding every answer's score for each patient.
Time frame: at baseline
Emotional eating questionnaire
The EEQ (Emotional eating Questionnaire) will be used extent emotions affect eating behaviour. . All the questions had four possible replies: 1) Never, 2) Sometimes; 3) Generally and 4) Always. Each reply was given a score of 1 to 4, the lower the score, the healthier the behaviour. For the clinical practice subjects are classified in four groups attending to the score obtained. Score between 0-5: non-emotional eater. Score between 6-10: low emotional eater. Score between 11-20: emotional eater. Score between 21-30: very emotional eater.
Time frame: at baseline
Physical activity questionnaire
by the IPAQ (international Physical Activity Questionnaire)
Time frame: at baseline
Mediterranean Diet Score questionnaire
By the questionnaire developed by Antonia Trichopoulou, M.D., Tina Costacou, Ph.D., Christina Bamia, Ph.D., and Dimitrios Trichopoulos, M.D. N Engl J Med 2003; 348:2599-2608June 26, 2003DOI: 10.1056/NEJMoa025039
Time frame: at baseline
Glucose tolerance
either by meal test or by glucose tolerance test
Time frame: from 1 year to 3 years after weight loss treatment
Daily rhythms of wrist temperature
7 day-record of wrist temperature by wrist temperature sensors.
Time frame: from 3 months to 3 years after weight loss treatment
Daily rhythms of activity
7 day-record of activity by actiwatch
Time frame: from 3 months to 3 years after weight loss treatment
Daily rhythms of autonomus system by ambulatory electrocardiography
7 days of ambulatory electrocardiography
Time frame: from 3 months to 3 years after weight loss treatment
Glucose
Fasting glucose
Time frame: at baseline
Insulin
Fasting insulin
Time frame: at baseline