Non-restrictive Approach to Facilitate Appetite Control and Long-term Body Weight Loss in Individuals With Obesity: Can we do Better?

The objective of this study is to evaluate (1) the effect of a non-restrictive satiating intervention on appetite control, body weight loss and maintenance; and (2) determine whether switching to a non-restrictive satiating intervention following a conventional restrictive intervention can prevent increases in appetite and attenuate body weight regain usually observed after weight loss in men and women living with obesity. This is an 18-month, randomized, controlled, parallel weight loss [Phase 1 (P1): 6 months] and maintenance trial [Phase 2 (P2): 12 months] with three groups (n=234 men and women): (1) non-restrictive, satiating intervention (P1) followed by a continuation of this intervention (P2); (2) conventional restrictive intervention (-500 kcal/d) (P1) followed by a non-restrictive satiating intervention (P2); (3) control group that follows minimal healthy guidelines (P1) followed by recommended weight maintenance strategies (P2). All groups will be controlled for physical activity and sleep patterns. The non-restrictive satiating intervention will include guidelines and recipes to prepare highly satiating meals that will be low in energy density and glycemic index and high in protein, polyunsaturated fats, vitamins and minerals (e.g. calcium), and certain constituents of spices (e.g. capsaicin). Measurements at baseline (week 0), after P1 and P2 will include the following primary outcomes: appetite control, weight loss and maintenance; and secondary outcomes: body composition, physiological, psycho and neurobehavioural and health-related variables. Follow-ups will be done by a dietitian every 2 weeks during P1 and once a month during P2.