Effects of Intermittent Versus Continuous Energy Restriction on Metabolic Adaptation in Women With Obesity

One of the major challenges for treating obesity is to maintain a weight reduced state on the long term due to the high rate of weight regain. Therefore, the aim of this study is to evaluate the effects of an intermittent versus a continuous energy restriction in body composition (body weight, fat mass and fat-free mass) and metabolic adaptation, in women with obesity.

Inclusion Criteria: * Women * BMI ranging between 30 and 39.9 kg/m2 * Age between 20-45 years * Weight stable in the last 6 months (less than 5% weigh variation) * Inactive (less then 150 min/week of moderate physical activity or 75 min/week of vigorous physical activity * Living in Lisbon Metropolitan Area and being able to drive to Faculty of Human Kinetics and Germano de Sousa Laboratory (Algés) * Available to be randomized to any of the trial groups (CER or IER) * Willing to commit with the assigned group protocol, including the nutritional intervention and lifestyle recommendations, as well as being available for participation in all evaluation moments. Exclusion Criteria: * Previous or present health disorders: cancer, autoimmune, cardiac, psychiatric, kidney and liver disease (except liver steatosis), diabetes, chronic intestinal inflammatory disease, or other medical conditions known to affect energy balance homeostasis * Menopause * Hormonal or thyroid disorder * Medications that promote weight gain or alter energy balance, including corticosteroids, antidepressants, anxiolytics, mood-stabilizing, and antipsychotics * Medications or dietary supplements for weight-loss in the past 3 months * Pregnant for the past 6 months or breastfeeding * Planning to get pregnant in the next 2 years or getting pregnant during the study * Current consumption of more than 14 alcoholic drinks per week or other substance abuse, and/or current acute treatment or rehabilitation program for alcohol/substance abuse * Surgery or in hospital admission for the last month * Positive for Covid-19 in the past 3 months or testing positive during the intervention phase of the study