Effects of Time-restricted Eating and Exercise Training on Skeletal Muscle Mass Quantity, Quality and Function in Postmenopausal Women With Overweight and Obesity

Participants will be required to reduce their eating time window to ≤ 8 hours/day. Women can choose when to begin eating, but the last meal should be completed before or at 20:00 hours (concentrating the eating window towards the active phase confers higher cardiometabolic health benefits). Our preliminary results suggest that this eating window is feasible and safe. Participants will receive dietary advice regarding the daily amount of high quality protein and meal-specific protein quantities. All the participants will attend a lifestyle education program based on Mediterranean diet and WHO physical activity recommendations every two weeks.

Sport sciences specialists will design, supervise and monitor the concurrent exercise intervention following the 2020 WHO recommendations. The program will be tailored to the participant's ability and health, and will be focused on a gradual increase to levels that are safe. Resistance training: 3 times/week designed to manage, attenuate and even prevent the loss of skeletal muscle tissue and function. The exercise sessions will be scheduled within or immediately after their eating window in order to maximize muscular muscle protein synthesis. Morning and afternoon training schedules will be offered to participants.

Individualised intensive behavioural intervention weight loss program including CR, exercise training and lifestyle education designed according to the current guidelines. CR will be tailored to participants (objectively assessed). Diet will provide 600 kcal/day less than the individual energy requirements based on measured resting energy expenditure (indirect calorimetry) and multiplied by an activity factor obtained by accelerometry. Experienced nutritionists will design personalized and balanced CR diet, and will train the participants through the food exchange system to follow the treatment. In those cases in which the CR compromised a protein intake of at least 1.2 g/kg/day, the macronutrient percentage distribution will be modified prioritizing achieving this minimum protein intake.